springboot教程-web（二）

撸了今年阿里、头条和美团的面试，我有一个重要发现.......>>>

第一节

现在开始springboot-web开发教程。

引入依赖，pom.xml

    4.0.0

    cn.ac.iie
    spring-course
    1.0-SNAPSHOT
    jar

    
        UTF-8
        1.8
        1.8
    

    
        
            
                org.springframework.boot
                spring-boot-dependencies
                2.1.4.RELEASE
                import
                pom
            
        
    

    
        
            org.springframework.boot
            spring-boot-starter-web
        
    

spring-boot-starter-web已经包含了spring-boot-starter依赖，因此只需引入这个依赖就可以了。

新建UserController.java

package com.edu.spring.springboot;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class UserController {

    @RequestMapping(value = "/user/home")
    @ResponseBody
    public String home() {
        return "user home";
    }

}

新建App.java

package com.edu.spring.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;


@SpringBootApplication
public class App {

    public static void main(String[] args) {
        SpringApplication.run(App.class, args);
    }

}

运行App.java，则服务器正常运行，默认端口号是8080，通过浏览器访问http://localhost:8080/user/home正常。

这样最简单的web开发就完成了。

如果要修改端口，可以再application.properties中修改：

server.port=8081

这样端口号就修改成功了。

默认的请求方式是：GET，POST，PUT方式都支持。我们可以限制他的请求方式：

方法一：

    @RequestMapping(value = "/user/home", method = RequestMethod.GET)
    @ResponseBody
    public String home() {
        return "user home";
    }

方法二：

使用GetMapping

    @GetMapping("/user/show")
    @ResponseBody
    public String show() {
        return "user home";
    }

    @PostMapping("/user/create")
    @ResponseBody
    public String create() {
        return "user home";
    }

GetMapping PostMapping等是spring4.3的新特性

如何传递参数

方法一：

修改UserController.java

    @PostMapping("/user/create")
    @ResponseBody
    public String create(@RequestParam("username") String username, @RequestParam("password") String password) {
        return "user create, username: " + username + ", password: " + password;
    }

@RequestParam注解默认是参数必须提供，如果可以不提供可以使用required=false

可以提供一个默认值defaultValue=""

方法二：

    @GetMapping("/user/{id}")
    @ResponseBody
    public String show(@PathVariable("id") String id) {
        return "user home id: " + id;
    }

方法三：

注入Servlet的api

    @GetMapping("/user/edit")
    @ResponseBody
    public String edit(HttpServletRequest httpServletRequest){
        return "user edit: " + httpServletRequest.getRemoteHost();
    }

我们发现每个方法都必须使用@ResponseBody来注释。因此可以使用RestController来简化

新建RoleController.java

package com.edu.spring.springboot;


import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class RoleController {

    @GetMapping("/role/show")
    public String show(){
        return "role show ";
    }
}

@RestController 表明了当前controller的方法的返回值可以直接用body输出。

如何在springboot中使用jsp

新建LoginController.java

package com.edu.spring.springboot;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;

@Controller
public class LoginController {
    @PostMapping("/login")
    public String login(@RequestParam("username") String username, @RequestParam(value = "password") String password) {
        if (username.equals(password)) {
            return "ok";
        }
        return "fail";
    }

}

在main文件夹下面新建webapp，与java和resources文件夹并列。

修改application.properties
 

spring.mvc.view.prefix=/WEB-INF/jsp/
spring.mvc.view.suffix=.jsp

在webapp目录下新建文件夹/WEB-INF/jsp，然后新建ok.jsp和fail.jsp

springboot默认是不支持使用jsp的

 在springboot中使用jsp，需要引入依赖：

        
            org.apache.tomcat.embed
            tomcat-embed-jasper
        

这样就可以成功访问jsp了。

如何向jsp传参数？

    @GetMapping("/loginIndex")
    public String loginIndex(Model model) {
        model.addAttribute("username", "root");
        model.addAttribute("password", "123456");
        return "login";
    }

新建login.jsp

username; ${username}
password: ${password}

在springboot中使用jsp时，不能使用@RestController, 而要使用@Controller

如何在Jsp中使用模板？

添加pom.xml依赖：并且删除jsp的依赖

        
            org.springframework.boot
            spring-boot-starter-freemarker
        

在application.properties中删除jsp的配置。

在springboot中使用freemarker的步骤：

1. 在pom中加入依赖，       

        
            org.apache.tomcat.embed
            tomcat-embed-jasper
       

2. 默认的freemaker的模板文件在classpath:/template/， 默认的文件扩展名为：ftl

新建AccountController.java

package com.edu.spring.springboot;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;

@Controller
public class AccountController {

    @GetMapping("/reg")
    public String reg(){
        return "reg";
    }

}

在resources/template下新建reg.ftl

    ftl reg

可以通过访问 http://192.168.170.132:8081/reg来获取这个模板页面了

如何修改模板文件的文件路径

在application.properties中修改：

spring.freemarker.template-loader-path=classpath:/ftl/  多个用逗号隔开

在resources下新建ftl文件夹，然后将reg.ftl文件移动到这个路径下，就可以访问了。

如何在模板文件中传参数

在AccountController.java

    @GetMapping("/logout")
    public String logout(Model model){
        model.addAttribute("username", "admin");
        model.addAttribute("logout", "true");
        return "logout";
    }

在ftl目录下新建logout.ftl文件:

logout
username: ${username}
logout is ${logout}

这样就传递参数到模板中了。

最好在项目中要么选择模板，要么选择jsp，不要二者都选。

Springboot默认容器是Tomcat，如果想换成Jetty，如何做

首先需要把tomcat排除掉。

        
            org.springframework.boot
            spring-boot-starter-web
            
                
                    org.springframework.boot
                    spring-boot-starter-tomcat
                
            
        

导入jetty依赖。

        
            org.springframework.boot
            spring-boot-starter-jetty
        

其余都不需要改变，直接运行，输出：

2019-05-15 21:00:56.619  INFO 14692 --- [           main] o.e.jetty.server.handler.ContextHandler  : Started o.s.b.w.e.j.JettyEmbeddedWebAppContext@37d3d232{application,/,[org.springframework.boot.web.embedded.jetty.JettyServletWebServerFactory$LoaderHidingResource@30c0ccff],AVAILABLE}
2019-05-15 21:00:56.619  INFO 14692 --- [           main] org.eclipse.jetty.server.Server          : Started @2652ms
2019-05-15 21:00:56.776  INFO 14692 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
2019-05-15 21:00:57.069  INFO 14692 --- [           main] o.e.j.s.h.ContextHandler.application     : Initializing Spring DispatcherServlet 'dispatcherServlet'
2019-05-15 21:00:57.070  INFO 14692 --- [           main] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
2019-05-15 21:00:57.075  INFO 14692 --- [           main] o.s.web.servlet.DispatcherServlet        : Completed initialization in 5 ms
2019-05-15 21:00:57.194  INFO 14692 --- [           main] o.e.jetty.server.AbstractConnector       : Started ServerConnector@614aeccc{HTTP/1.1,[http/1.1]}{0.0.0.0:8081}
2019-05-15 21:00:57.196  INFO 14692 --- [           main] o.s.b.web.embedded.jetty.JettyWebServer  : Jetty started on port(s) 8081 (http/1.1) with context path '/'
2019-05-15 21:00:57.198  INFO 14692 --- [           main] com.edu.spring.springboot.App            : Started App in 2.8 seconds (JVM running for 3.23)

说明容器已经变成jetty了。

添加项目名称

默认是不需要有项目名称的，在application.properties文件中修改：

server.servlet.context-path=/mall

在地址栏中，需要指定/mall才能访问。例如：http://192.168.170.132:8081/mall/logout

第二节

如何在springboot中访问静态资源

1. src/main/webapp 下可以直接访问

2. 默认的静态资源路径是：classpath：[/META-INF/resources/, * /resources/, /static/, /public/] 源码在org.springframework.boot.autoconfigure.web包中

3. 可以通过spring.resources.static-locations配置项修改默认静态资源路径

方法一：

在src/main/webapp下新建user.html

    
    


    
this is user page 

可以直接在浏览器访问http://localhost:8080/user.html，说明直接将html页面放到webapp下面就可以直接访问了。

在webapp下面新建目录img，在img目录中拷贝一张图片进去my.jpg,在user.html中添加图片，。这样可以直接在user.html中访问图片了。

方法二：

在resources下新建文件夹public

在resources/public 下新建login.html，

    
    


this is login html page. 在public下

访问http://localhost:8080/login.html 可以访问成功。

在public下新建css文件夹，新建main.css

body {
    color: red;
}

在login.html中引入这个main.css文件

访问login.html页面可以成功访问，字体颜色生效。

方法三：

在application.properties中添加：

spring.resources.static-locations=classpath:/html/

在resources中新建文件夹html

然后在resources/html/中新建index.html页面，

重启以后可以直接访问http://localhost:8080/index.html

如何在springboot中使用Servlet

新建UserServlet.java，并且继承HTTPServlet

使用Servlet3.0注解

package com.edu.spring.springboot;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet("/user.do")
public class UserServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().println("user servlet");
    }
}

修改App.java ，将Servlet添加到spring容器中。

package com.edu.spring.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;

@ServletComponentScan
@SpringBootApplication
public class App {

    public static void main(String[] args) {
        SpringApplication.run(App.class, args);
    }

}

运行，可以通过浏览器访问http://localhost:8080/user.do

如何在springboot容器中使用Servlet filter

新建LogFilter.java

package com.edu.spring.springboot;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;

@WebFilter("/user.do")
public class LogFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("income log filter " + servletRequest.getRemoteHost());
        filterChain.doFilter(servletRequest, servletResponse);
    }

    @Override
    public void destroy() {

    }
}

这个Filter可以拦截user.do请求。运行访问http://localhost:8080/user.do时，控制台输出结果：

income log filter 0:0:0:0:0:0:0:1

如何在springboot中使用Listener

新建MyContextListener.java

package com.edu.spring.springboot;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;
import java.time.LocalDateTime;

@WebListener
public class MyContextListener implements ServletContextListener {
    @Override
    public void contextInitialized(ServletContextEvent sce) {
        System.out.println("app start up at: " + LocalDateTime.now().toString());
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {

    }
}

这个监听器将监听应用程序启动。启动程序时，控制台将会输出：

app start up at: 2019-05-16T15:09:23.084

如何不使用上述方法，实现Servlet的API

新建包com.edu.spring.springboot.servlet，在这个包下面新建BookServlet.java

package com.edu.spring.springboot.servlet;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class BookServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().println("book servlet output");
    }
}

在这个包下新建ServletConfiguration.java

package com.edu.spring.springboot.servlet;

import org.springframework.boot.SpringBootConfiguration;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;

@SpringBootConfiguration
public class ServletConfiguration {

    @Bean
    public ServletRegistrationBean createBookServlet() {
        ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new BookServlet(), "/book.do");
        return servletRegistrationBean;
    }

}

修改App.java

package com.edu.spring.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class App {

    public static void main(String[] args) {
        SpringApplication.run(App.class, args);
    }

}

浏览器输入http://localhost:8080/book.do返回结果正常

使用这个方法，不用在Servlet上使用注释，也不用使用@ServletComponentScan注释。

同理，可以使用这个方法使用Filter

在Servlet这个包下新建EchoFilter.java

package com.edu.spring.springboot.servlet;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

public class EchoFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest httpServletRequest = (HttpServletRequest) servletRequest;
        System.out.println("spring boot web filter " + httpServletRequest.getRequestURI());
        filterChain.doFilter(servletRequest, servletResponse);
    }

    @Override
    public void destroy() {

    }
}

在ServletConfiguration.java中添加bean

    @Bean
    public FilterRegistrationBean createFilterRegistraionBean() {
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
        filterRegistrationBean.setFilter(new EchoFilter());
        filterRegistrationBean.setUrlPatterns(Arrays.asList("/book.do"));
        return filterRegistrationBean;
    }

浏览器上输入http://localhost:8080/book.do，控制台输出：

spring boot web filter /book.do

同理，新建StartUpListener.java

package com.edu.spring.springboot.servlet;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

public class StartUpListener implements ServletContextListener {
    @Override
    public void contextInitialized(ServletContextEvent sce) {
        System.out.println("===========");
        System.out.println("application is started");
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {

    }
}

在ServletConfiguration.java中添加bean

    @Bean
    public ServletListenerRegistrationBean createServletListenerRegistrationBean() {
        ServletListenerRegistrationBean servletListenerRegistrationBean = new ServletListenerRegistrationBean(new StartUpListener() );
        return servletListenerRegistrationBean;
    }

运行App.java，在应用程序运行开始，控制台输出：

===========
application is started

总结

    springboot 中使用Servlet的API

方法一：    

    1. 编写Servlet，然后加上相应的注解

    2. 需要启用@ServletComponentScan注解 

    servlet2.5以上版本 可以使用这种方法使用

    这种方法更方便一些。

方法二：

    1. 编写Servlet，

    2.  装配相应的bean到spring容器中

        Servlet -> ServletRegistrationBean

        Filter -> FilterRegistrationBean

        Listener -> ServletListenerRegistrationBean 

    Servlet2.5及以下版本可以使用这种方法

第三节

如何在springboot中使用拦截器

新建UserController.java

package com.edu.spring.springboot;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class UserController {

    @GetMapping("/user/home")
    public String home() {
        System.out.println("----user---home");
        return "user home";
    }

}

新建LogHandlerInterceptor.java

package com.edu.spring.springboot;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class LogHandlerInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("=preHandle=====" + handler.getClass());

        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("=postHandle=====");

    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("=afterCompletion=====");

    }
}

新建WebConfiguration.java

package com.edu.spring.springboot;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

@Configuration
public class WebConfiguration extends WebMvcConfigurerAdapter {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new LogHandlerInterceptor());
    }
}

或者：

package cn.ac.iie.authorization.config;

import cn.ac.iie.authorization.interceptor.AuthorizationInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class MvcConfig implements  WebMvcConfigurer {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new LogHandlerInterceptor());
    }
}

这里的@Configuration注释可以替换为@SpringBootConfiguration

运行App.java，然后在浏览器中输入http://127.0.0.1:8080/user/home，正常显示user home

控制台输出：

=preHandle=====class org.springframework.web.method.HandlerMethod
----user---home
=postHandle=====
=afterCompletion=====

总结：拦截器的使用步骤

    1. 写一个拦截器，实现HandlerInterceptor接口

    2. 写一个类，继承WebvcConfigurereAdapter抽象类，然后重写addInterceptors方法，并调用registry.addInterceptor把上一步的拦截器加进去

HanderInterceptor

    1. preHanle: controller执行之前调用

    2. postHandle: controller执行之后，且页面渲染之前调用

    3. afterCompletion: 页面渲染之后调用，一半用于资源清理操作

springboot开发中的异常处理 

将拦截器关闭，注释WebConfiguration.java中的@Configuration

在UserController.java中添加方法：

    @GetMapping("/user/help")
    public String help() {
        throw new IllegalArgumentException("args is empty");
    }

当页面请求/user/help的时候抛出异常，运行App.java

浏览器输入http://127.0.0.1:8080/user/help，浏览器显示如下：

Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.

Sun May 19 22:03:18 CST 2019
There was an unexpected error (type=Internal Server Error, status=500).
args is empty

同时控制台输出：

java.lang.IllegalArgumentException: args is empty
	at com.edu.spring.springboot.UserController.help(UserController.java:17) ~[classes/:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_144]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_144]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_144]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_144]
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:189) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]

如何使用我们自己的异常页面？

方法一

默认的异常页面在ErrorMvcAutoConfiguration.java中定义，我们需要将这个类排除掉。

package com.edu.spring.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration;


@SpringBootApplication(exclude = ErrorMvcAutoConfiguration.class)
public class App {

    public static void main(String[] args) {
        SpringApplication.run(App.class, args);
    }

}

这时，我们如果在浏览器中输入一个不存在的网址时例如http://127.0.0.1:8080/user/help000，出现404的错误。

如果在浏览器中输入http://127.0.0.1:8080/user/help，出现500错误页面。

如何去掉springboot 默认的异常处理逻辑？

@SpringBootApplication(exclude = ErrorMvcAutoConfiguration.class)

 如何使用自己的异常逻辑页面？

在resoures下新建文件夹public，这时默认的web页面访问路径，在public文件夹下面新建404.html和500.html

    
    


404 not found

    
    


500 error

新建CommonErrorPageRegistry.java

package com.edu.spring.springboot;

import org.springframework.boot.web.server.ErrorPage;
import org.springframework.boot.web.server.ErrorPageRegistrar;
import org.springframework.boot.web.server.ErrorPageRegistry;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Component;

@Component
public class CommonErrorPageRegistry implements ErrorPageRegistrar {

    @Override
    public void registerErrorPages(ErrorPageRegistry registry) {
        ErrorPage e404 = new ErrorPage(HttpStatus.NOT_FOUND, "/404.html");
        ErrorPage e500 = new ErrorPage(HttpStatus.INTERNAL_SERVER_ERROR, "/500.html");
        registry.addErrorPages(e404, e500);
    }
}

浏览器中输入http://127.0.0.1:8080/user/help000和http://127.0.0.1:8080/user/help分别跳转到我们自定义的页面

总结：

    使用ErrorPageRegistrar方法

    写一个类，实现ErrorPageRegistrar接口，然后实现registerErrorPage方法，在该方法里面，添加具体的错误处理逻辑（类似web.xml有里面配置错误处理方法）

 如果我们想单独给IllegalArgumentException异常渲染一个页面，如何做？

修改CommonErrorPageRegistry.java

package com.edu.spring.springboot;

import org.springframework.boot.web.server.ErrorPage;
import org.springframework.boot.web.server.ErrorPageRegistrar;
import org.springframework.boot.web.server.ErrorPageRegistry;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Component;

@Component
public class CommonErrorPageRegistry implements ErrorPageRegistrar {

    @Override
    public void registerErrorPages(ErrorPageRegistry registry) {
        ErrorPage e404 = new ErrorPage(HttpStatus.NOT_FOUND, "/404.html");
        ErrorPage e500 = new ErrorPage(HttpStatus.INTERNAL_SERVER_ERROR, "/500.html");
        ErrorPage args = new ErrorPage(IllegalArgumentException.class, "/args.html");
        registry.addErrorPages(e404, e500, args);
    }
}

这样IllegalArgumentException异常可以单独页面渲染了。

方法二：

首先将上一种方式屏蔽，将CommonErrorPageRegistry.java中的@Component注释掉

新建BookController.java

package com.edu.spring.springboot;

import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.io.FileNotFoundException;

@RestController
public class BookController {

    @ExceptionHandler(value = FileNotFoundException.class)
    public String error(Exception e) {
        return "file not found exception" + e.getMessage();
    }

    @GetMapping("/book/error1")
    public String error1() throws FileNotFoundException {
        throw new FileNotFoundException("book.txt not found");
    }

    @GetMapping("/book/error2")
    public String error2() throws ClassNotFoundException {
        throw new ClassNotFoundException("book.class not found");
    }

}

在BookController.java中定义当前Controller中的异常，这个error方法将捕获到FileNotFoundException并返回file not found exception，捕获不到FileNotFound异常。并且这个只对当前Controller生效。对UserController中的异常并不处理。

如果要对当前Controller中的所有异常都捕获，则@ExceptionHandler(value = Exception.class)

如何对所有Controller生效？

新建GlobalExceptionHandler.java

package com.edu.spring.springboot;

import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;

@ControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(value = Exception.class)
    @ResponseBody
    public String errorHandler(Exception e) {
        return "global error " + e.getClass().getName();
    }

}

这样就可以捕获所有的Controller中的异常。

全局异常处理

    1. 写一个类，需要加上@ControllerAdvice注解

    2. 写一个异常处理方法，方法上面需要加上@ExceptionHandler(value=Exception.class)这个注解，然后在该方法里面处理异常

第四节

springboot如何定制和优化内嵌的Tomcat

springboot默认集成了2种web容器分别是tomcat和jetty

新建UserController.java

package com.edu.spring.springboot;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class UserController {

    @GetMapping("/user/home")
    public String home(){
        return "user home";
    }

}

在application.properties中修改端口号

server.port=8081

运行应用程序，在浏览器中输入网址：http://127.0.0.1:8081/user/home和http://192.168.170.132:8081/user/home都可以访问成功

在application.properties中添加：

server.port=8081
server.address=192.168.170.132

运行应用程序，在浏览器中输入http://127.0.0.1:8081/user/home就无法访问了，说明ip绑定成功。

可以启用tomcat日志：

server.port=8081
server.address=192.168.170.132
server.tomcat.accesslog.enabled=true
server.tomcat.accesslog.directory=F:/test

如何通过代码的方式配置tomcat

注释application.properties中的内容

新建MyEmbeddedServletContainerFactory.java

package com.edu.spring.springboot;

import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;


@Configuration
public class MyEmbeddedServletContainerFactory {
    @Bean
    public TomcatServletWebServerFactory servletContainer() {
        TomcatServletWebServerFactory tomcat = new TomcatServletWebServerFactory();
        tomcat.setPort(8081);
        return tomcat;
    }
}

同样端口号修改为8081

设置tomcat连接数和线程数：

package com.edu.spring.springboot;

import org.apache.catalina.connector.Connector;
import org.apache.catalina.valves.AccessLogValve;
import org.apache.coyote.http11.Http11NioProtocol;
import org.springframework.boot.web.embedded.tomcat.TomcatConnectorCustomizer;
import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;


@Configuration
public class MyEmbeddedServletContainerFactory {
    @Bean
    public TomcatServletWebServerFactory servletContainer() {
        TomcatServletWebServerFactory tomcat = new TomcatServletWebServerFactory();
        tomcat.setPort(8081);
        tomcat.addConnectorCustomizers(new MyTomcatConnectorCustomizer());
        return tomcat;
    }
    class MyTomcatConnectorCustomizer implements TomcatConnectorCustomizer {

        @Override
        public void customize(Connector connector) {
            Http11NioProtocol protocol=(Http11NioProtocol) connector.getProtocolHandler();
            //设置最大连接数
            protocol.setMaxConnections(2000);
            //设置最大线程数
            protocol.setMaxThreads(500);
        }

    }
}

添加tomcat日志，和404错误重定向页面

package com.edu.spring.springboot;

import org.apache.catalina.connector.Connector;
import org.apache.catalina.valves.AccessLogValve;
import org.apache.coyote.http11.Http11NioProtocol;
import org.springframework.boot.web.embedded.tomcat.TomcatConnectorCustomizer;
import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory;
import org.springframework.boot.web.server.ErrorPage;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.HttpStatus;


@Configuration
public class MyEmbeddedServletContainerFactory {
    @Bean
    public TomcatServletWebServerFactory servletContainer() {
        TomcatServletWebServerFactory tomcat = new TomcatServletWebServerFactory();
        tomcat.setPort(8081);
        tomcat.addContextValves(getLogAccessLogValve());
        tomcat.addErrorPages(new ErrorPage(HttpStatus.NOT_FOUND,"/404.html"));
        tomcat.addInitializers(servletContext -> System.out.println("servlet start up =========="));
        tomcat.addConnectorCustomizers(new MyTomcatConnectorCustomizer());
        return tomcat;
    }

    private AccessLogValve getLogAccessLogValve(){
        AccessLogValve log = new AccessLogValve();
        log.setDirectory("F:/test");
        log.setEnabled(true);
        log.setPattern("common");
        log.setPrefix("springboot--");
        log.setSuffix(".txt");
        return log;
    }
    class MyTomcatConnectorCustomizer implements TomcatConnectorCustomizer {

        @Override
        public void customize(Connector connector) {
            Http11NioProtocol protocol=(Http11NioProtocol) connector.getProtocolHandler();
            //设置最大连接数
            protocol.setMaxConnections(2000);
            //设置最大线程数
            protocol.setMaxThreads(500);
        }

    }
}

总结

定制和优化Tomcat，以编码的方式设置Tomcat的各个属性值，以及Tomcat的日志配置

TomcatServletWebServerFactory纳入spring容器中管理

当我们的springboot中没有自定义的web容器，那么springboot使用自己的tomcat，如果我们自定义了容器，则使用我们自定义的tomcat。 原因如下：在org.springframework.boot.autoconfigure.web.embedded包下

@Configuration
@ConditionalOnWebApplication
@EnableConfigurationProperties(ServerProperties.class)
public class EmbeddedWebServerFactoryCustomizerAutoConfiguration {

	/**
	 * Nested configuration if Tomcat is being used.
	 */
	@Configuration
	@ConditionalOnClass({ Tomcat.class, UpgradeProtocol.class })
	public static class TomcatWebServerFactoryCustomizerConfiguration {

		@Bean
		public TomcatWebServerFactoryCustomizer tomcatWebServerFactoryCustomizer(
				Environment environment, ServerProperties serverProperties) {
			return new TomcatWebServerFactoryCustomizer(environment, serverProperties);
		}

	}

第五节

spring JDBC配置

引入pom.xml

        
            org.springframework.boot
            spring-boot-starter-jdbc
        
        
            mysql
            mysql-connector-java
        

application.properties

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://192.168.152.45:3306/renyuanku
spring.datasource.username=root
spring.datasource.password=123456

在App.java中使用数据源

package com.edu.spring.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration;
import org.springframework.context.ConfigurableApplicationContext;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;

@SpringBootApplication
public class App {
    public static void main(String[] args) {
        ConfigurableApplicationContext configurableApplicationContext = SpringApplication.run(App.class, args);
        DataSource dataSource = configurableApplicationContext.getBean(DataSource.class);
        try {
            Connection connection = dataSource.getConnection();
            System.out.println(connection.getCatalog());
            connection.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

}

运行结果输出数据库名。

总结：

    装配DataSource的步骤

    1.  加入数据库驱动

    2.  配置数据源

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://192.168.152.45:3306/renyuanku
spring.datasource.username=root
spring.datasource.password=123456

以上操作，springboot会自动装配好DataSource，JDBCTemplate，可以直接使用

 数据库使用JDBCTemplate操作数据库

新建ProductDao.java

package com.edu.spring.springboot;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

@Repository
public class ProductDao {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    public void addProduct(String id){
        String sql = "insert into test (id) values ("+ id + ")";
        jdbcTemplate.execute(sql);
    }

}

修改App.java

package com.edu.spring.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration;
import org.springframework.context.ConfigurableApplicationContext;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;

@SpringBootApplication
public class App {
    public static void main(String[] args) {
        ConfigurableApplicationContext configurableApplicationContext = SpringApplication.run(App.class, args);
        DataSource dataSource = configurableApplicationContext.getBean(DataSource.class);
        try {
            Connection connection = dataSource.getConnection();
            System.out.println(connection.getCatalog());
            connection.close();
            ProductDao bean = configurableApplicationContext.getBean(ProductDao.class);
            bean.addProduct("123");
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

}

执行App.java，查询数据库，可以看到执行成功

查看Springboot用的什么数据源

package com.edu.spring.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration;
import org.springframework.context.ConfigurableApplicationContext;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;

@SpringBootApplication
public class App {
    public static void main(String[] args) {
        ConfigurableApplicationContext configurableApplicationContext = SpringApplication.run(App.class, args);
        DataSource dataSource = configurableApplicationContext.getBean(DataSource.class);
        System.out.println(dataSource.getClass());
    }

}

输出结果：

class com.zaxxer.hikari.HikariDataSource

可以看到使用的是HikariDataSource数据源

如何使用其他数据源

在application.properties中配置

spring.datasource.type=

可以指定具体使用哪种数据源，springboot默认支持一下数据源，在类中org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration

	@Import({ DataSourceConfiguration.Hikari.class, DataSourceConfiguration.Tomcat.class,
			DataSourceConfiguration.Dbcp2.class, DataSourceConfiguration.Generic.class,
			DataSourceJmxConfiguration.class })

Hikari,tomcat,dbcp2,generic,放到classpath下

如何自己配置数据源

添加druid数据源依赖

        
            com.alibaba
            druid
            1.1.6
        

新建DBConfiguration.java

package com.edu.spring.springboot;

import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringBootConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.core.env.Environment;

import javax.sql.DataSource;

@SpringBootConfiguration
public class DBConfiguration {

    @Autowired
    private Environment environment;

    @Bean
    public DataSource createDataSource() {
        DruidDataSource druidDataSource = new DruidDataSource();
        druidDataSource.setUrl(environment.getProperty("spring.datasource.url"));
        druidDataSource.setUsername(environment.getProperty("spring.datasource.username"));
        druidDataSource.setPassword(environment.getProperty("spring.datasource.password"));
        druidDataSource.setDriverClassName(environment.getProperty("spring.datasource.driver-class-name"));
        return druidDataSource;
    }

}

application.properties

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://192.168.152.45:3306/renyuanku
spring.datasource.username=root
spring.datasource.password=123456

App.java

package com.edu.spring.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration;
import org.springframework.context.ConfigurableApplicationContext;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;

@SpringBootApplication
public class App {
    public static void main(String[] args) {
        ConfigurableApplicationContext configurableApplicationContext = SpringApplication.run(App.class, args);
        DataSource dataSource = configurableApplicationContext.getBean(DataSource.class);
        System.out.println(dataSource.getClass());
    }

}

运行输出：

class com.alibaba.druid.pool.DruidDataSource

说明数据源已经变为Druid了。

springboot的特点是优先使用自己的配置，然后使用spring默认配置。

同样可以使用JDBCTemplate

修改App.java

public class App {
    public static void main(String[] args) {
        ConfigurableApplicationContext configurableApplicationContext = SpringApplication.run(App.class, args);
        DataSource dataSource = configurableApplicationContext.getBean(DataSource.class);
        try {
            Connection connection = dataSource.getConnection();
            System.out.println(connection.getCatalog());
            connection.close();
            ProductDao bean = configurableApplicationContext.getBean(ProductDao.class);
            bean.addProduct("124");
        } catch (SQLException e) {
            e.printStackTrace();
        }
        System.out.println(dataSource.getClass());
    }

}

成功插入数据124

Springboot对事务也做了很好的集成

修改ProductDao.java

package com.edu.spring.springboot;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;

@Repository
public class ProductDao {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    public void addProduct(String id){
        String sql = "insert into test (id) values ("+ id + ")";
        jdbcTemplate.execute(sql);
    }

    @Transactional
    public void addProductBatch(String ...ids) throws FileNotFoundException {
        for(String id: ids){
            String sql = "insert into test (id) values ("+ id + ")";
            jdbcTemplate.execute(sql);
            if("".equals("")) {
                throw new FileNotFoundException();
            }
        }

    }

}

使用事务需要在方法上添加注释@Transactional

然后在App.java启用事务，添加注释@EnableTransactionManagement

@SpringBootApplication
@EnableTransactionManagement
public class App {
    public static void main(String[] args) {
        ConfigurableApplicationContext configurableApplicationContext = SpringApplication.run(App.class, args);
        DataSource dataSource = configurableApplicationContext.getBean(DataSource.class);
        try {
            Connection connection = dataSource.getConnection();
            System.out.println(connection.getCatalog());
            connection.close();
            ProductDao bean = configurableApplicationContext.getBean(ProductDao.class);
            try {
                bean.addProductBatch("111", "222", "333", "444", "555");
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        System.out.println(dataSource.getClass());
    }

}

然后执行，报异常，查询数据库发现存入了一条数据 111，说明事务没有生效。

原因是spring默认会对运行时的异常进行事务的操作，而fileNotFound不是运行时的异常，我们需要修改为RunTimeException。修改：

    @Transactional
    public void addProductBatch(String ...ids) throws FileNotFoundException {
        for(String id: ids){
            String sql = "insert into test (id) values ("+ id + ")";
            jdbcTemplate.execute(sql);
            if("".equals("")) {
                throw new NullPointerException();
            }
        }

    }

然后运行App.java，报出异常，查询数据库，没有插入数据，说明事务生效。

事务

    首先要使用@EnableTransactionManagement启用对事务的支持

    然后在需要使用事务的方法上面加上@Transactional

    注意，默认只会对运行时异常进行事务回滚，非运行时异常不会回滚事务

 如何回滚非运行时异常

使用@Transactional(rollbackFor = Exception.class)可以回滚所有异常

    @Transactional(rollbackFor = Exception.class)
    public void addProductBatch(String ...ids) throws FileNotFoundException {
        for(String id: ids){
            String sql = "insert into test (id) values ("+ id + ")";
            jdbcTemplate.execute(sql);
            if("".equals("")) {
                throw new FileNotFoundException();
            }
        }

    }

如何不回滚某些异常

使用@Transactional(noRollbackFor = NullPointerException.class)

    @Transactional(rollbackFor = Exception.class, noRollbackFor = NullPointerException.class)
    public void addProductBatch(String ...ids) throws Exception {
        for(String id: ids){
            String sql = "insert into test (id) values ("+ id + ")";
            jdbcTemplate.execute(sql);
            if("".equals("")) {
                throw new NullPointerException();
            }
        }

    }

注意：@Transactional必须要标注在纳入到spring容器管理bean的公有方法，例如：

    @Transactional()
    public void addTest(String ...ids){
        add(ids);
    }

    @Transactional()
    private void add(String ...ids){
        for(String id: ids){
            String sql = "insert into test (id) values ("+ id + ")";
            jdbcTemplate.execute(sql);
            if("".equals("")) {
                throw new NullPointerException();
            }
        }
    }

运行App.java可以成功插入数据库，事务没有生效。

注意：直接调用的方法必须要使用@Transactional注释，否则不能回滚

第六节

SpringAOP

日志记录、权限处理、监控、异常处理

添加依赖pom.xml

    4.0.0

    cn.ac.iie
    spring-course
    1.0-SNAPSHOT
    jar

    
        UTF-8
        1.8
        1.8
    

    
        
            
                org.springframework.boot
                spring-boot-dependencies
                2.1.4.RELEASE
                import
                pom
            
        
    

    
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            org.springframework.boot
            spring-boot-starter-aop
        
    

新建包dao，在dao下面新建UserDao.java

package com.edu.spring.springboot.dao;

import org.springframework.stereotype.Component;

@Component
public class UserDao {
    public void add (String username, String password){
        System.out.println("add: username:" + username + ",password:" + password);
    }
}

新建LogAspect.java

package com.edu.spring.springboot;

import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.springframework.stereotype.Component;

@Aspect
@Component
public class LogAspect {

    @Before("execution(* com.edu.spring.springboot.dao..*.*(..))")
    public void log() {
        System.out.println("method log done" );
    }

}

execution(* com.edu.spring.springboot.dao..*.*(..)) 表示织入到com.edu.spring.springboot.dao及其子包下面的所有的类的所有的方法。

执行的时机就是，前置执行。

App.java

package com.edu.spring.springboot;

import com.edu.spring.springboot.dao.UserDao;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;

@SpringBootApplication
public class App {
    public static void main(String[] args) {
        ConfigurableApplicationContext configurableApplicationContext = SpringApplication.run(App.class, args);
        configurableApplicationContext.getBean(UserDao.class).add("admin", "123456");
        configurableApplicationContext.close();
    }

}

运行结果：

method log done
add: username:admin,password:123456

这是一个最简单的AOP。

AOP开发流程

    1. spring-boot-starter-aop加入依赖，默认开启了AOP的支持

    2. 写一个Aspect，封装横切关注点（日志，监控等等），需要配置通知（前置通知，后置通知等等）和切入点（哪些包的哪些类的哪些方法等等）；

    3. 这个Aspect需要纳入到spring容器管理，并且需要加入@Aspect注解

在application.properties中配置：

spring.aop.auto=false

表示不启用aop，默认是为true启用，运行App.java，结果如下：

add: username:admin,password:123456

在application.properties中配置：

spring.aop.auto=true
spring.aop.proxy-target-class=false

spring.aop.proxy-target-class默认是true，false表示使用的是JDK的动态代理，true表示使用CGLIB的动态代理

JDK的动态代理需要一个接口

新建IUserDao.java

package com.edu.spring.springboot.dao;

public interface IUserDao {
    public void add (String username, String password);
}

然后让UserDao实现这个接口，修改App.java

package com.edu.spring.springboot;

import com.edu.spring.springboot.dao.UserDao;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;

@SpringBootApplication
public class App {
    public static void main(String[] args) {
        ConfigurableApplicationContext configurableApplicationContext = SpringApplication.run(App.class, args);
        System.out.println(configurableApplicationContext.getBean(UserDao.class).getClass());
        configurableApplicationContext.getBean(UserDao.class).add("admin", "123456");
        configurableApplicationContext.close();
    }

}

运行报错：

Exception in thread "main" org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.edu.spring.springboot.dao.UserDao' available
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:343)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:335)
	at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1123)
	at com.edu.spring.springboot.App.main(App.java:12)

原因是基于JDK的动态代理之后，就不能根据class来获取对象，需要根据接口来获取对象。

@SpringBootApplication
public class App {
    public static void main(String[] args) {
        ConfigurableApplicationContext configurableApplicationContext = SpringApplication.run(App.class, args);
        System.out.println(configurableApplicationContext.getBean(IUserDao.class).getClass());
        configurableApplicationContext.getBean(IUserDao.class).add("admin", "123456");
        configurableApplicationContext.close();
    }

}

运行输出结果如下：

class com.sun.proxy.$Proxy55
method log done
add: username:admin,password:123456

这是典型的动态代理。

将spring.aop.proxy-target-class改为true，运行结果如下：

class com.edu.spring.springboot.dao.UserDao$$EnhancerBySpringCGLIB$$62d64f2d
method log done
add: username:admin,password:123456

总结：

    aop默认是使用基于JDK的动态代理来实现AOP，默认启用

    spring.aop.proxy-target-class=true或者不配置，表示使用cglib的动态代理，

    =false表示jdk动态代理

    如果配置了false，而类没有借口，则依然使用cglib

将application.properties中的配置注释掉。

如何得到aop相关参数

修改LogAspect.java

package com.edu.spring.springboot;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.springframework.stereotype.Component;

import java.util.Arrays;

@Aspect
@Component
public class LogAspect {

    @Before("execution(* com.edu.spring.springboot.dao..*.*(..))")
    public void log() {
        System.out.println("before method log done" );
    }

    @After("execution(* com.edu.spring.springboot.dao..*.*(..))")
    public void logAfter(JoinPoint point) {
        System.out.println("before method log done" + point.getTarget().getClass() + ", args="+ Arrays.asList(point.getArgs()) + ", method=" + point.getSignature().getName());
    }

}

输出结果如下：

class com.edu.spring.springboot.dao.UserDao$$EnhancerBySpringCGLIB$$abbff7d9
before method log done
add: username:admin,password:123456
before method log doneclass com.edu.spring.springboot.dao.UserDao, args=[admin, 123456]

虽然springboot默认支持了AOP，但是springboot依然提供了enable的注解，@EnableAspectJAutoProxy

第七节 Springboot starter

新建RedisProperties.java

package com.edu.spring.springboot;

import org.springframework.boot.context.properties.ConfigurationProperties;

@ConfigurationProperties(prefix = "redis")
public class RedisProperties {
    private String host;
    private Integer port;

    public String getHost() {
        return host;
    }

    public void setHost(String host) {
        this.host = host;
    }

    public Integer getPort() {
        return port;
    }

    public void setPort(Integer port) {
        this.port = port;
    }
}

新建RedisConfiguration.java

package com.edu.spring.springboot;

import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import redis.clients.jedis.Jedis;

@Configuration
@ConditionalOnClass(Jedis.class)
@EnableConfigurationProperties(RedisProperties.class)
public class RedisAutoConfiguration {

    @Bean
    @ConditionalOnMissingBean
    public Jedis jedis(RedisProperties redisProperties){
        Jedis jedis = new Jedis(redisProperties.getHost(), redisProperties.getPort());
        System.out.println("springbourse bean" + jedis);
        return jedis;
    }
}

这样的话spring容器在装配Jedis这个bean的时候会先从容器中获取RedisProperties这个bean，然后传到这个方法中去。

@ConditionalOnClass(Jedis.class)表示装配这个bean的时候Jedis.class这个类一定要存在。

@ConditionalOnMissingBean表示没有这个Jedis这个类的时候，我们才装配。

新建项目spring-course-redis，将上面的项目加到这个项目中去：pom.xml如下

    4.0.0

    cn.ac.iie
    spring-course-redis
    1.0-SNAPSHOT

    
        UTF-8
        1.8
        1.8
    

    
        
            
                org.springframework.boot
                spring-boot-dependencies
                2.1.4.RELEASE
                import
                pom
            
        
    

    
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            cn.ac.iie
            spring-course
            1.0-SNAPSHOT
        
    

加入好依赖以后，在spring-course-redis项目中我们可以直接从容器中获取jedis了，App.java如下：

package com.edu.spring.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;
import redis.clients.jedis.Jedis;

@SpringBootApplication
public class App {
    public static void main(String[] args) {
        ConfigurableApplicationContext configurableApplicationContext = SpringApplication.run(App.class, args);
        Jedis jedis = configurableApplicationContext.getBean(Jedis.class);
        System.out.println("springbourseredis bean" + jedis);
        jedis.set("id", "vincent");
        System.out.println(jedis.get("id"));
    }

}

新建application.properties,内容如下：

redis.host=192.168.152.45
redis.port=6379

运行App.java输出如下：

springbourse beanredis.clients.jedis.Jedis@60bdf15d
springbourseredis beanredis.clients.jedis.Jedis@60bdf15d
vincent

说明已经成功注入进去了。

但是在springboot1.X版本中是无法直接这样使用的。

解决方法有两种，

方法一：

    在springbootcourse项目中，新建EnableRedis.java，需要使用@Import注解

package com.edu.spring.springboot;

import org.springframework.context.annotation.Import;

import java.lang.annotation.*;

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Import(RedisAutoConfiguration.class)
public @interface EnableRedis {
}

    在springbootcourseredis项目中，添加@EnableRedis注解

@EnableRedis
@SpringBootApplication
public class App {
    public static void main(String[] args) {
        ConfigurableApplicationContext configurableApplicationContext = SpringApplication.run(App.class, args);
        Jedis jedis = configurableApplicationContext.getBean(Jedis.class);
        System.out.println("springbourseredis bean" + jedis);
        jedis.set("id", "vincent");
        System.out.println(jedis.get("id"));
    }

}

方法二：

使用spring.factories

在springbootcourse项目中在resources目录下，新建/META-INF文件夹，然后在这个文件夹下新建spring.factories文件，内容如下：

org.springframework.boot.autoconfigure.EnableAutoConfiguration=com.edu.spring.springboot.RedisAutoConfiguration

总结

    springboot2.x 可以直接使用

    springboot1.x 需要进行配置。

自己开发一个spring boot  starter的步骤

1. 新建一个项目

2. 需要一个配置类，配置类里面需要装配好需要提供出去的类

3. 使用

    (1)@Enable ，使用@Import导入需要装配的类

    (2)/META-INF/spring.factories， 在org.springframework.boot.autoconfigure.EnableAutoConfiguration配置需要装配的类

第八节 springboot日志

默认的日志输出结果如下：

2019-05-26 14:29:27.650  INFO 641 --- [           main] com.edu.spring.springboot.App            : Starting App on duandingyangdeMacBook-Pro.local with PID 641 (/Users/duandingyang/git-project/springcourse/target/classes started by duandingyang in /Users/duandingyang/git-project/springcourse)
2019-05-26 14:29:27.654  INFO 641 --- [           main] com.edu.spring.springboot.App            : No active profile set, falling back to default profiles: default
2019-05-26 14:29:28.804  INFO 641 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
2019-05-26 14:29:28.834  INFO 641 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2019-05-26 14:29:28.835  INFO 641 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.17]
2019-05-26 14:29:28.931  INFO 641 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2019-05-26 14:29:28.931  INFO 641 --- [           main] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 1230 ms
2019-05-26 14:29:29.203  INFO 641 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
2019-05-26 14:29:29.409  INFO 641 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
2019-05-26 14:29:29.416  INFO 641 --- [           main] com.edu.spring.springboot.App            : Started App in 2.638 seconds (JVM running for 3.64)

日志级别为Info ，进程ID（PID）641 , 线程名字main，所在类，日志内容。

新建dao包，然后在这个dao包下新建UserDao.java

package com.edu.spring.springboot.dao;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

@Component
public class UserDao {
    private Logger logger = LoggerFactory.getLogger(UserDao.class);

    public void log() {
        logger.debug("user dao debug log");
        logger.info("user dao info log");
        logger.warn("user dao warn log");
        logger.error("user dao error log");
    }
}

App.java内容如下:

package com.edu.spring.springboot;

import com.edu.spring.springboot.dao.UserDao;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;


@SpringBootApplication
public class App {
    public static void main(String[] args) {

        ConfigurableApplicationContext run = SpringApplication.run(App.class, args);
        run.getBean(UserDao.class).log();
        run.close();

    }

}

运行输出结果如下：

2019-05-26 14:35:24.170  INFO 787 --- [           main] com.edu.spring.springboot.dao.UserDao    : user dao info log
2019-05-26 14:35:24.170  WARN 787 --- [           main] com.edu.spring.springboot.dao.UserDao    : user dao warn log
2019-05-26 14:35:24.170 ERROR 787 --- [           main] com.edu.spring.springboot.dao.UserDao    : user dao error log

说明日志的默认级别是info。

如何调整日志级别？

方法一：

修改application.properties

logging.level.*=DEBUG

可以通过logging.level.*=debug 来设置，* 可以是包，也可以是某个类。

方法二

在program arguments中设置--debug，也可以启用DEBUG，但是这种方式无法输出我们自己的DEBUG信息，只可以输出Spring的debug

新建service包，然后在这个包下新建UserService.java

package com.edu.spring.springboot.service;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class UserService {
    private Logger logger = LoggerFactory.getLogger(UserService.class);

    public void log() {
        logger.debug("user service debug log");
        logger.info("user service info log");
        logger.warn("user service warn log");
        logger.error("user service error log");
    }
}

如果我们只想在service包下面使用debug，则需要修改application.properties内容：

logging.level.com.edu.spring.springboot.service=DEBUG

在App.java中添加

run.getBean(UserService.class).log();

输出结果如下：

2019-05-26 14:54:20.149  INFO 843 --- [           main] com.edu.spring.springboot.dao.UserDao    : user dao info log
2019-05-26 14:54:20.149  WARN 843 --- [           main] com.edu.spring.springboot.dao.UserDao    : user dao warn log
2019-05-26 14:54:20.149 ERROR 843 --- [           main] com.edu.spring.springboot.dao.UserDao    : user dao error log
2019-05-26 14:54:20.149 DEBUG 843 --- [           main] c.e.s.springboot.service.UserService     : user service debug log
2019-05-26 14:54:20.149  INFO 843 --- [           main] c.e.s.springboot.service.UserService     : user service info log
2019-05-26 14:54:20.149  WARN 843 --- [           main] c.e.s.springboot.service.UserService     : user service warn log
2019-05-26 14:54:20.149 ERROR 843 --- [           main] c.e.s.springboot.service.UserService     : user service error log

service启用了debug，dao默认的info

日志级别有：trace，debug，info，warn，error，fatal，off
日至级别off表示关闭日志

如何配置日志输出文件？

application.properties

logging.file=/Users/vincent/my.log

指定日志文件路径与名字。

logging.path 也可以指定日志的路径，此时名字为spring.log

日志文件输出，文件的大小10M之后，就会分割了

如何指输出日志格式

logging.pattern.console=%-20(%d{yyy-MM-dd} [%thread]) %-5level %logger{80} - %msg%n
logging.file.console=%-20(%d{yyy-MM-dd HH:mm:ss.SSS} [%thread]) %-5level %logger{80} - %msg%n

分别为控制台的日志输出格式和文件日志输出格式

使用logback

在resources下新建logback.xml

    
        
            %-20(%d{yyy-MM-dd HH:mm:ss.SSS} [%thread]) %-5level %logger{80} - %msg%n
        
    
    
        
    

springboot 默认支持logback，也就是说，只需要在classpath下放一个logback.xml或者logback-spring.xml的文件，即可定制日志的输出。

如何使用log4j2

现将默认的日志排除,并且加入log4j依赖，pom.xml

    4.0.0

    cn.ac.iie
    spring-course
    1.0-SNAPSHOT
    jar

    
        UTF-8
        1.8
        1.8
    

    
        
            
                org.springframework.boot
                spring-boot-dependencies
                2.1.4.RELEASE
                import
                pom
            
        
    

    
        
            org.springframework.boot
            spring-boot-starter-web
            
                
                    org.springframework.boot
                    spring-boot-starter-logging
                
            
        
        
            org.springframework.boot
            spring-boot-starter-log4j2
        
    

在resources目录下新建log4j2.xml

运行App.java，输出结果为：

2019-05-27 23:28:51.808 [main] DEBUG com.edu.spring.springboot.dao.UserDao - user dao debug log
2019-05-27 23:28:51.808 [main] INFO  com.edu.spring.springboot.dao.UserDao - user dao info log
2019-05-27 23:28:51.808 [main] WARN  com.edu.spring.springboot.dao.UserDao - user dao warn log
2019-05-27 23:28:51.808 [main] ERROR com.edu.spring.springboot.dao.UserDao - user dao error log
2019-05-27 23:28:51.808 [main] DEBUG com.edu.spring.springboot.service.UserService - user service debug log
2019-05-27 23:28:51.808 [main] INFO  com.edu.spring.springboot.service.UserService - user service info log
2019-05-27 23:28:51.808 [main] WARN  com.edu.spring.springboot.service.UserService - user service warn log
2019-05-27 23:28:51.808 [main] ERROR com.edu.spring.springboot.service.UserService - user service error log

说明log4j2配置成功。当然了，log4j2.xml 文件名也可以改为log4j2-spring.xml

使用其他的日志组件的步骤
 1：排除掉默认的日志组件spring-boot-starter-logging
 2：加入新的日志组件依赖
 3：把相应的日志文件加到classpath下

 springboot 的相关日志源码在org.springframework.boot.logging包下面，其中LogLevel.java定义了日志级别，LoggingSystemProperties定义了日志配置项。

第九节 springboot监控和度量

添加依赖pom.xml

    4.0.0

    cn.ac.iie
    spring-course
    1.0-SNAPSHOT
    jar

    
        UTF-8
        1.8
        1.8
    

    
        
            
                org.springframework.boot
                spring-boot-dependencies
                2.1.4.RELEASE
                import
                pom
            
        
    

    
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            org.springframework.boot
            spring-boot-actuator
        
    

    spring boot2.x中，默认只开放了info、health两个端点，其余的需要自己通过配置management.endpoints.web.exposure.include属性来加载（有include自然就有exclude）。如果想单独操作某个端点可以使用management.endpoint.端点.enabled属性进行启用或者禁用。

Endpoints

    Actuator endpoints 允许你去监控和操作你的应用。SpringBoot包含了许多内置的端点，当然你也可以添加自己的端点。比如 health 端点就提供了基本的应用健康信息。

Metrics

    Spring Boot Actuator 提供 dimensional metrics 通过集成 Micrometer.

Audit

    Spring Boot Actuator 有一套灵活的审计框架会发布事件到 AuditEventRepository。

springboot 2.x 默认只启动了 health 和 info 端点，可以通过 application.properties 配置修改：

management.endpoints.web.exposure.include=health,info,env,metrics

项目启动时可以看到暴露出来的接口信息：

2019-05-30 18:47:35.162  INFO 9888 --- [           main] o.s.b.a.e.web.EndpointLinksResolver      : Exposing 4 endpoint(s) beneath base path '/actuator'

浏览器中输入http://localhost:8080/actuator/，结果如下：

{
    "_links": {
        "self": {
            "href": "http://localhost:8080/actuator",
            "templated": false
        },
        "health-component": {
            "href": "http://localhost:8080/actuator/health/{component}",
            "templated": true
        },
        "health-component-instance": {
            "href": "http://localhost:8080/actuator/health/{component}/{instance}",
            "templated": true
        },
        "health": {
            "href": "http://localhost:8080/actuator/health",
            "templated": false
        },
        "env": {
            "href": "http://localhost:8080/actuator/env",
            "templated": false
        },
        "env-toMatch": {
            "href": "http://localhost:8080/actuator/env/{toMatch}",
            "templated": true
        },
        "info": {
            "href": "http://localhost:8080/actuator/info",
            "templated": false
        },
        "metrics": {
            "href": "http://localhost:8080/actuator/metrics",
            "templated": false
        },
        "metrics-requiredMetricName": {
            "href": "http://localhost:8080/actuator/metrics/{requiredMetricName}",
            "templated": true
        }
    }
}

浏览器中输入：http://localhost:8080/actuator/metrics/system.cpu.usage，结果如下：

{
    "name": "system.cpu.usage",
    "description": "The \"recent cpu usage\" for the whole system",
    "baseUnit": null,
    "measurements": [
        {
            "statistic": "VALUE",
            "value": 0.24420139608387495
        }
    ],
    "availableTags": []
}

常用的endpoint：

HTTP方法	路径	描述
GET	/autoconfig	查看自动配置的使用情况
GET	/configprops	查看配置属性，包括默认配置
GET	/beans	查看bean及其关系列表
GET	/dump	打印线程栈
GET	/env	查看所有环境变量
GET	/env/{name}	查看具体变量值
GET	/health	查看应用健康指标
GET	/info	查看应用信息
GET	/mappings	查看所有url映射
GET	/metrics	查看应用基本指标
GET	/metrics/{name}	查看具体指标
POST	/shutdown	关闭应用
GET	/trace	查看基本追踪信息

想要查看服务器的健康状态详细信息，需要配置application.properties

management.endpoint.health.show-details=always

这样就可以查看健康状态的详细信息了，例如磁盘利用情况，数据库情况。

如何自定义健康状态检查？

新建MyHealthIndicator.java

package com.edu.spring.springboot;

import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.actuate.health.HealthIndicator;
import org.springframework.stereotype.Component;

@Component
public class MyHealthIndicator implements HealthIndicator {
    @Override
    public Health health() {
        return Health.up().withDetail("error","springboot error").build();
    }
}

在浏览器中输入http://localhost:8080/actuator/health可以看到自定义的健康状态监控。

总结：

    自定义健康状态监测，实现HealthIndicator接口，并纳入spring容器的管理之中。

使用info，

在application.properties中使用info开头的信息都可以显示出来，例如：

info.name=myinfo
info.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

在浏览器中输入，http://localhost:8080/actuator/info 可以查看到这些配置信息。

可以对git信息进行监控。

Prometheus Grafana实现应用可视化监控

第十节 打包springboot

pom.xml文件：

    4.0.0

    cn.ac.iie
    spring-course
    1.0-SNAPSHOT
    jar

    
        UTF-8
        1.8
        1.8
    

    
        
            
                org.springframework.boot
                spring-boot-dependencies
                2.1.4.RELEASE
                import
                pom
            
        
    

    
        
            org.springframework.boot
            spring-boot-starter-web
        
    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
                2.1.4.RELEASE
                
                    com.edu.spring.springboot.App
                
                
                    
                        
                            repackage
                        
                    
                
            
        
    

一定要指定mainClass才可以

springboot 测试

添加pom.xml依赖

    4.0.0

    cn.ac.iie
    spring-course
    1.0-SNAPSHOT
    jar

    
        UTF-8
        1.8
        1.8
    

    
        
            
                org.springframework.boot
                spring-boot-dependencies
                2.1.4.RELEASE
                import
                pom
            
        
    

    
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            org.springframework.boot
            spring-boot-starter-test
            test
        
    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
                2.1.4.RELEASE
                
                    com.edu.spring.springboot.App
                
                
                    
                        
                            repackage
                        
                    
                
            
        
    

新建UserDao.java

package com.edu.spring.springboot.dao;

import org.springframework.stereotype.Repository;

@Repository
public class UserDao {

    public Integer addUser(String username) {
        System.out.println("user dao adduser " + username);
        if(username == null) {
            return 0;
        }
        return 1;
    }

}

在Intellij下Ctrl + Shift + T 新建测试类UserDaoTest.java

package com.edu.spring.springboot.dao;

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import static org.junit.Assert.*;

@RunWith(SpringRunner.class)
@SpringBootTest
public class UserDaoTest {

    @Autowired
    private UserDao userDao;

    @Test
    public void addUser() {
        Assert.assertEquals(Integer.valueOf(1), userDao.addUser("root"));
        Assert.assertEquals(Integer.valueOf(0), userDao.addUser(null));
    }
}

输出结果如下：

user dao adduser root
user dao adduser null

springboot测试步骤，

    直接在测试类上面添加下面的注解：

        @RunWith(SpringRunner.class)

        @SpringBootTest

Test下的包名和java下的包名应该一致。

如何测试bean?

新建User.java并且纳入到spring容器管理中去。

package com.edu.spring.springboot.bean;

import org.springframework.stereotype.Component;

@Component
public class User {

}

新建测试类ApplicationContextTest.java

package com.edu.spring.springboot.dao;

import com.edu.spring.springboot.bean.User;
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.context.ApplicationContext;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class ApplicationContextTest {

    @Autowired
    private ApplicationContext applicationContext;

    @Test
    public void testNull() {
        Assert.assertNotNull(applicationContext.getBean(User.class));

    }

}

输出结果可以显示，输出正常。

如何在测试类中自定义一个bean？

在src/test/java/com/edu/springboot/dao下新建TestBeanConfiguration.java

package com.edu.spring.springboot.dao;

import org.springframework.boot.test.context.TestConfiguration;
import org.springframework.context.annotation.Bean;

@TestConfiguration
public class TestBeanConfiguration {

    @Bean
    public Runnable createRunnable() {
        return () -> {};
    }

}

然后在ApplicationContextTest.java 指定classes

package com.edu.spring.springboot.dao;

import com.edu.spring.springboot.bean.User;
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.context.ApplicationContext;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest(classes = TestBeanConfiguration.class)
public class ApplicationContextTest {

    @Autowired
    private ApplicationContext applicationContext;

    @Test
    public void testNull() {
        Assert.assertNotNull(applicationContext.getBean(User.class));
        Assert.assertNotNull(applicationContext.getBean(Runnable.class));
    }

}

指定classes=TestBeanConfiguration.class就可以使用这个bean了。

使用@TestConfiguration可以在测试环境下指定bean。如果在App.java 中使用这个bean，那么会报错，找不到这个bean。

只有在测试环境下有效。

    测试环境下，只能用@TestConfiguration，不能用@Configuration

如何环境测试 

在test/java/com/edu/spring/springboot/dao下 新建EnvTest.java 

package com.edu.spring.springboot.dao;

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.core.env.Environment;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class EnvTest {

    @Autowired
    private Environment environment;

    @Test
    public void testValue() {
        Assert.assertEquals("myapplication", environment.getProperty("spring.application.name"));
    }

}

在main/resources/application.properties内容如下：

spring.application.name=myapplication

测试运行正常。

如果我们的application.properties在test/resources/下怎么办？

在test下新建文件夹resources，然后在test/resources/目录下新建application.properties，内容如下：

spring.application.name=myapplication-test

然后运行EnvTest.java文件，报错：

Expected :myapplication
Actual   :myapplication-test

说明这里面的配置文件，优先去取test/resources中的application.properties，如果没有这个配置文件，则去main/resoures中去取。

在测试环境中，springboot会优先加载测试环境下的配置文件(application.properties)

测试环境下没有，才会加载正式环境下的配置文件。

测试环境中自定义指定配置项 

(properties = {"app.version=1.0.0"})：

package com.edu.spring.springboot.dao;

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.core.env.Environment;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest(properties = {"app.version=1.0.0"})
public class EnvTest {

    @Autowired
    private Environment environment;

    @Test
    public void testValue() {
        Assert.assertEquals("myapplication-test", environment.getProperty("spring.application.name"));
        Assert.assertEquals("1.0.0", environment.getProperty("app.version"));
    }

}

运行成功。

Mock如何测试接口？

新建mapper包，在包下新建UserMapper.java

package com.edu.spring.springboot.mapper;

public interface UserMapper {
    Integer createUser(String username);
}

在Test下，新建UserDaoTest.java

package com.edu.spring.springboot.mapper;

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.BDDMockito;
import org.springframework.boot.test.mock.mockito.MockBean;
import org.springframework.test.context.junit4.SpringRunner;
@RunWith(SpringRunner.class)
public class UserMapperTest {

    @MockBean
    private UserMapper userMapper;

    @Test(expected = NullPointerException.class)
    public void createUser() {
        BDDMockito.given(userMapper.createUser("admin")).willReturn(Integer.valueOf(1));
        BDDMockito.given(userMapper.createUser("")).willReturn(Integer.valueOf(0));
        BDDMockito.given(userMapper.createUser(null)).willThrow(NullPointerException.class);

        Assert.assertEquals(Integer.valueOf(1), userMapper.createUser("admin"));
        Assert.assertEquals(Integer.valueOf(0), userMapper.createUser(""));
        Assert.assertEquals(Integer.valueOf(0), userMapper.createUser(null));
    }
}

因为接口并没有实现类，因此需要做提前预测，BDDMockito.given就是这个功能。当user.createUser()的输入时admin时，返回整型1，当user.createUser()的输入是“”时，返回整型0，当user.createUser()的输入时null时，返回异常。

mock方法可以卸载init方法中，如下所示：

package com.edu.spring.springboot.mapper;

import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.BDDMockito;
import org.springframework.boot.test.mock.mockito.MockBean;
import org.springframework.test.context.junit4.SpringRunner;
@RunWith(SpringRunner.class)
public class UserMapperTest {

    @MockBean
    private UserMapper userMapper;

    @Before
    public void init() {
        BDDMockito.given(userMapper.createUser("admin")).willReturn(Integer.valueOf(1));
        BDDMockito.given(userMapper.createUser("")).willReturn(Integer.valueOf(0));
        BDDMockito.given(userMapper.createUser(null)).willThrow(NullPointerException.class);
    }

    @Test(expected = NullPointerException.class)
    public void createUser() {
        Assert.assertEquals(Integer.valueOf(1), userMapper.createUser("admin"));
        Assert.assertEquals(Integer.valueOf(0), userMapper.createUser(""));
        Assert.assertEquals(Integer.valueOf(0), userMapper.createUser(null));
    }
}

对Controller进行测试

方法一：

新建BookController.java

package com.edu.spring.springboot.controller;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class BookController {

    @GetMapping("/book/home")
    public String home() {
        System.out.println("/book/home url is invoke");
        return "book home";
    }

}

新建测试类BookControllerTest.java

package com.edu.spring.springboot.controller;

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.web.client.TestRestTemplate;
import org.springframework.test.context.junit4.SpringRunner;

import static org.junit.Assert.*;

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class BookControllerTest {

    @Autowired
    private TestRestTemplate testRestTemplate;

    @Test
    public void home() {
        String forObject = testRestTemplate.getForObject("/book/home", String.class);
        Assert.assertEquals("book home", forObject);
    }
}

TestRestTemplate 需要在web环境中，因此需要SpringBootTest.WebEnvironment.RANDOM_PORT

 在BookController.java中添加方法，测试有参数的Controller方法：

    @GetMapping("/book/show")
    public String show(@RequestParam("id") String id) {
        System.out.println("/book/show url is invoke");
        return "book" + id;
    }

在测试方法中：

    @Test
    public void show() {
        String forObject = testRestTemplate.getForObject("/book/show?id=100", String.class);
        Assert.assertEquals("book100", forObject);
    }

方法二：

新建测试类BookControllerTest2.java

package com.edu.spring.springboot.controller;

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.web.client.TestRestTemplate;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.MockMvcBuilder;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
import org.springframework.test.web.servlet.result.MockMvcResultHandlers;
import org.springframework.test.web.servlet.result.MockMvcResultMatchers;

@RunWith(SpringRunner.class)
@WebMvcTest(controllers = BookController.class)
public class BookControllerTest2 {

    @Autowired
    private MockMvc mockMvc;

    @Test
    public void home() throws Exception {
        mockMvc.perform(MockMvcRequestBuilders.get("/book/home")).andExpect(MockMvcResultMatchers.status().isOk());
        mockMvc.perform(MockMvcRequestBuilders.get("/book/home")).andExpect(MockMvcResultMatchers.status().isOk()).andExpect(MockMvcResultMatchers.content().string("book home"));
    }


}

@WebMvcTest 不需要运行在web环境下，但是，需要指定controllers，表示需要测试哪些controller

 修改BookController.java，使用UserDao

package com.edu.spring.springboot.controller;

import com.edu.spring.springboot.dao.UserDao;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class BookController {

    @Autowired
    private UserDao userDao;

    @GetMapping("/book/home")
    public String home() {
        System.out.println("/book/home url is invoke");
        return "book home";
    }

    @GetMapping("/book/show")
    public String show(@RequestParam("id") String id) {
        System.out.println("/book/show url is invoke");
        userDao.addUser("aaa");
        return "book" + id;
    }

}

报错信息如下：

java.lang.IllegalStateException: Failed to load ApplicationContext
	at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:125) ~[spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:108) ~[spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:118) ~[spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:83) ~[spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.boot.test.autoconfigure.SpringBootDependencyInjectionTestExecutionListener.prepareTestInstance(SpringBootDependencyInjectionTestExecutionListener.java:44) ~[spring-boot-test-autoconfigure-2.1.4.RELEASE.jar:2.1.4.RELEASE]
	at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:246) ~[spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:227) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:289) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) [junit-4.12.jar:4.12]
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:291) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:246) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290) [junit-4.12.jar:4.12]
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) [junit-4.12.jar:4.12]
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) [junit-4.12.jar:4.12]
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58) [junit-4.12.jar:4.12]
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) [junit-4.12.jar:4.12]
	at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363) [junit-4.12.jar:4.12]
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190) [spring-test-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137) [junit-4.12.jar:4.12]
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68) [junit-rt.jar:na]
	at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47) [junit-rt.jar:na]
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242) [junit-rt.jar:na]
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70) [junit-rt.jar:na]
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'bookController': Unsatisfied dependency expressed through field 'userDao'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.edu.spring.springboot.dao.UserDao' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:596) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:374) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1411) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:592) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
	

说没有UserDao对象。因为使用@WebMvcTest方式测试，不会加载整个spring容器，只能测试controller。Controller里面的一些依赖，需要自己去mock。

但是使用@SpringBootTest方式是可以把整个spring容器加载进来的。但不能和@WebMvcTest同时使用

如果要使用@SpringBootTest，则无法使用MockMVC，如果要是用MockMvc需要添加@AutoConfigureMockMvc，如下所示

package com.edu.spring.springboot.controller;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
import org.springframework.test.web.servlet.result.MockMvcResultMatchers;

@RunWith(SpringRunner.class)
@SpringBootTest
@AutoConfigureMockMvc
public class BookControllerTest3 {

    @Autowired
    private MockMvc mockMvc;

    @Test
    public void home() throws Exception {
        mockMvc.perform(MockMvcRequestBuilders.get("/book/home")).andExpect(MockMvcResultMatchers.status().isOk());
        mockMvc.perform(MockMvcRequestBuilders.get("/book/home")).andExpect(MockMvcResultMatchers.status().isOk()).andExpect(MockMvcResultMatchers.content().string("book home"));
    }

    @Test
    public void show() throws Exception {
        mockMvc.perform(MockMvcRequestBuilders.get("/book/show").param("id", "400")).andExpect(MockMvcResultMatchers.status().isOk());
        mockMvc.perform(MockMvcRequestBuilders.get("/book/show").param("id", "400")).andExpect(MockMvcResultMatchers.status().isOk()).andExpect(MockMvcResultMatchers.content().string("book400"));
    }

}