Spring3.1.1学习笔记04-aurora-mvc
上一节完成后，运行起来后，应该能看到index.jsp的HelloWorld内容了，在这一节加入SpringMVC支持。
1、首先新建一个config文件，用来配置SpringMVC的拦截器。
src/main/java-org.aurora.config-ApplicationContextServletConfigruation.java
package org.aurora.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
@Configuration
public class ApplicationContextSevlteConfigruation {
@Bean
public ViewResolver viewResolver() {
InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
viewResolver.setPrefix("/WEB-INF/views/");
viewResolver.setSuffix(".jsp");
return viewResolver;
}
}
2、因为用到了spring-webmvc，spring-webmvc又依赖了cglib，所以在pom.xml中加入这两个依赖。
<dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> </dependency>
<dependency> <groupId>cglib</groupId> <artifactId>cglib</artifactId> </dependency>
3、将拦截器加入到web容器中，方法和web.xml文件的配置一样，只是不用xml文件格式了。修改src/main/java-org.aurora.config-ApplicationInitialize.java，增加一个dispatcher的监听器。这个监听器拦截所有“/”下的资源。
package org.aurora.config;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration;
import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.ContextLoaderListener;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;
public class ApplicationInitialize implements WebApplicationInitializer {
public void onStartup(ServletContext servletContext) throws ServletException {
AnnotationConfigWebApplicationContext rootContext = new AnnotationConfigWebApplicationContext();
servletContext.addListener(new ContextLoaderListener(rootContext));
/**
* Spring mvc dispatcher
*/
ServletRegistration.Dynamic dispatcher = servletContext.addServlet("dispatcher", new DispatcherServlet(rootContext));
dispatcher.setLoadOnStartup(1);
dispatcher.addMapping("/");
}
}
4、下面的问题是到哪里去找SpringMVC的拦截器呢，xml时代是有个默认的地方，默认的名称，比如上面的描述，就应该是到WEB-INF下面去找到一个叫dispatcher-servlet.xml的文件，web容器会自动加载进来，当然，也可以自定义路径，我们这里也自定义了，这个类名叫ApplicationContextServletConfigruation，所以，这个容器中还需要加入一行代码，表示到哪里去寻找这个文件。
package org.aurora.config;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration;
import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.ContextLoaderListener;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;
public class ApplicationInitialize implements WebApplicationInitializer {
public void onStartup(ServletContext servletContext) throws ServletException {
AnnotationConfigWebApplicationContext rootContext = new AnnotationConfigWebApplicationContext();
rootContext.scan("org.aurora.config");
servletContext.addListener(new ContextLoaderListener(rootContext));
/**
* Spring mvc dispatcher
*/
ServletRegistration.Dynamic dispatcher = servletContext.addServlet("dispatcher", new DispatcherServlet(rootContext));
dispatcher.setLoadOnStartup(1);
dispatcher.addMapping("/");
}
}
就是这句rootContext.scan("org.aurora.config");就好比去xml中的dispatcher-*.xml一样，这里使用包扫描方式将“org.aurora.config”下面所有有@Configuration注解的类全部扫描一遍。
5、修改一下index.jsp，这个文件以后不用了，让他自动跳转到home.jsp去。
<jsp:forward page="home" />
6、我们看到，这个页面跳转到了一个叫home的地址，这是个虚拟地址，SpringMVC会将这个地址处理成真实的页面，所以，这里还需要建立一个核心类，这和SpringMVC以前的版本没有什么区别。
src/main/java-org.aurora.controller-HomeController.java
package org.aurora.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
@Controller
public class HomeController {
@RequestMapping(value = "/home", method = RequestMethod.GET)
public String login() {
return "home";
}
}
7、现在构建一个home.jsp页面，因为我们拦截的是"/WEB-INF/views/"下的所有".jsp"文件，所以需要在WEB-INF目录下建立一个views目录存放jsp文件。src/main/webapp/WEB-INF/views/home.jsp
<html> <head> <title>Home Page</title> </head> <body> <h1>Hello World</h1> </body> </html>
8、测试一下，还是访问http://localhost:8080/index.jsp，发现404错误，找不到home，这个问题是因为src/main/java/org/aurora/config/ApplicationContextSevlteConfigruation.java的配置里只是设置了拦截器，具体是拦截什么没有说明，所以这里需要添加一个注解
package org.aurora.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
@Configuration
@ComponentScan(basePackages = {"org.aurora.controller"})
public class ApplicationContextSevlteConfigruation {
@Bean
public ViewResolver viewResolver() {
InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
viewResolver.setPrefix("/WEB-INF/views/");
viewResolver.setSuffix(".jsp");
return viewResolver;
}
}
就是这一句@ComponentScan(basePackages = {"org.aurora.controller"})，指定到org.aurora.controller包里去扫描所有有@controller注解的类
9、再测试一下，应该正常了。
10、为了日后方便，再加入一个注解@EnableWebMvc，这个注解一次性为我们导入了springmvc需要的很多bean。最终代码如下：
package org.aurora.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
@Configuration
@EnableWebMvc
@ComponentScan(basePackages = {"org.aurora.controller"})
public class ApplicationContextSevlteConfigruation {
@Bean
public ViewResolver viewResolver() {
InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
viewResolver.setPrefix("/WEB-INF/views/");
viewResolver.setSuffix(".jsp");
return viewResolver;
}
}