Springmvc详解
SpringMVC详解
javaSE、javaWeb、框架（建议研究官方文档，锻炼项目）
将来的技术栈：SpringMvc+Vue+SpringBoot+Linux
SpringMvc的执行流程（重点，面试常问问题）
注：SPringMVC的第一个项目的网址： http://c.biancheng.net/spring_mvc/first-program.html
1、SpringMvc
1.1、简介
MVC：模型（dao,service）、视图（jsp）、控制器（servlet）
定义：
- 是一种软件的设计的规范
- 是将业务逻辑、数据、显示分离的方法来组织代码
- MVC主要的作用时降低了视图与业务逻辑之间的双向耦合
- MVC不是一种设计模式，而是一种架构模式
前端、数据传输、实体类（pojo、vo、dto）
SpringMvc是一种基于java实现的web框架
SpringMVC的特点
- 轻量级
- 高效，基于请求相应的MVC框架
- 与Spring兼容性好，无缝结合
- 约定大于配置
- 功能强大，RESTful、数据验证、格式化、本地化、主题等。
- 简介灵活
Spring的web框架围绕DispatcherServlet（调度servlet）设计的，DispatcherServlet的作用时将请求分发到不同的处理器
1.2、SPringMVC的运行流程
1.3、第一个SpringMVC项目
所需要的maven依赖
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<parent>
<artifactId>SpringMVCartifactId>
<groupId>org.examplegroupId>
<version>1.0-SNAPSHOTversion>
parent>
<modelVersion>4.0.0modelVersion>
<artifactId>SpringMVC-01artifactId>
<dependencies>
<dependency>
<groupId>junitgroupId>
<artifactId>junitartifactId>
<version>4.13version>
dependency>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>javax.servlet-apiartifactId>
<version>3.1.0version>
dependency>
<dependency>
<groupId>javax.servlet.jspgroupId>
<artifactId>javax.servlet.jsp-apiartifactId>
<version>2.3.1version>
dependency>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>jstlartifactId>
<version>1.2version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-webmvcartifactId>
<version>5.1.0.RELEASEversion>
dependency>
dependencies>
<properties>
<maven.compiler.source>9maven.compiler.source>
<maven.compiler.target>9maven.compiler.target>
properties>
<build>
<resources>
<resource>
<directory>src/main/javadirectory>
<includes>
<include>**/*.xmlinclude>
includes>
resource>
resources>
build>
project>
SpringMVC所需要的配置的web.xml
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<welcome-file-list>
<welcome-file>index.jspwelcome-file>
welcome-file-list>
<servlet>
<servlet-name>SpriDispatcherServletngservlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
<init-param>
<param-name>contextConfigLocationparam-name>
<param-value>classpath:springmvc-servlet.xmlparam-value>
init-param>
<load-on-startup>1load-on-startup>
servlet>
<servlet-mapping>
<servlet-name>SpriDispatcherServletngservlet-name>
<url-pattern>/url-pattern>
servlet-mapping>
web-app>
所需要配置的springmvc-servlet.xml文件的内容
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd">
<bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"/>
<bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter" />
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/"/>
<property name="suffix" value=".jsp"/>
bean>
<bean class="com.li.Controller.HelloSpringMVC" id="/hello"/>
beans>
java类的实现
package com.li.Controller;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class HelloSpringMVC implements Controller {
@Override
public ModelAndView handleRequest(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws Exception {
ModelAndView modelAndView=new ModelAndView();
String resoult="HelloSpringMVC";
modelAndView.addObject("msg",resoult);
modelAndView.setViewName("test");
return modelAndView;
}
}
1.4、开发中的相关文件的配置
web.xml文件的内容
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<welcome-file-list>
<welcome-file>index.jspwelcome-file>
welcome-file-list>
<servlet>
<servlet-name>SpriDispatcherServletngservlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
<init-param>
<param-name>contextConfigLocationparam-name>
<param-value>classpath:springmvc-servlet.xmlparam-value>
init-param>
<load-on-startup>1load-on-startup>
servlet>
<servlet-mapping>
<servlet-name>SpriDispatcherServletngservlet-name>
<url-pattern>/url-pattern>
servlet-mapping>
web-app>
springmvc-servlet.xml的文件内容
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<context:component-scan base-package="com.li.Controller" />
<mvc:default-servlet-handler/>
<mvc:annotation-driven/>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/"/>
<property name="suffix" value=".jsp"/>
bean>
<bean class="com.li.Controller.HelloSpringMVC" id="/hello"/>
beans>
1.5、Controller
控制器Controller
- 控制器复杂提供访问应用程序的行为，通常通过接口定义或注解定义两种方法实现
- 控制器负责解析用户的请求并将其转化为一个模型
- 在SpringMVC中一个控制器可以包含多个方法
- 子啊SpringMVC中，对于COntroller的配置方式有多种
常见的实现方式
- 通过调用COntroller接口（当时先了Controller接口的类，则其具有了控制器的功能，会接受请求并返回一个ModelAndView）
- 注解的方式@Controller（建议使用）
1.6、RestFul风格
概念：RestFul就是一个资源定位及资源操作的风格，不是标准也不是协议，只是一种风格。基于这个风格设计的软件可以更加的简介，更有层次，更易于实现缓存等机制。
功能：
- 资源：互联网所有的事务都可以被抽象资源
- 资源操作：使用POST、DELETE、PUT、GET，使用不同的方法对资源进行操作
- 分别对应添加、删除、修改、查询。
优点：安全、简洁、高效
常见错误：404页面跳转失败、405不支持相关的写法、500内部代码错误
1.7、数据处理
处理提交数据
1、注：提交的域名和处理方法的参数名一致
2、注：提交的域名和处理方法的参数名称不一致通过@RequestParm(“xx”)进行重命名
例
3、前端提交一个对象采用对象的封装
Model、ModelMap、ModelAndView之间的对比
- Model：只有寥寥的几个方法，只适合用于存储数据，简化了新手对于Model对象的操作与理解
- ModelMap：继承了LinkeMap，除了实现自身的一些方法，同样继承LinkeMap的方法和特性
- ModelAndView：可以在存储数据的同时，可以进行设置返回的逻辑视图，进行控制展示层的跳转。
1.8、乱码问题的解决
参考网站：https://www.cnblogs.com/melodyjerry/p/13562572.html
第一种(自己创建过滤器)
package com.li.util;
import javax.servlet.*;
import java.io.IOException;
public class filter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
servletRequest.setCharacterEncoding("utf-8");
servletResponse.setCharacterEncoding("utf-8");
}
@Override
public void destroy() {
}
}
第二种（在web.xml文件中引进SpringMVC中自带的过滤器）
<filter>
<description>字符集过滤器description>
<filter-name>encodingFilterfilter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilterfilter-class>
<init-param>
<param-name>encodingparam-name>
<param-value>UTF-8param-value>
init-param>
<init-param>
<param-name>forceEncodingparam-name>
<param-value>trueparam-value>
init-param>
filter>
<filter-mapping>
<filter-name>encodingFilterfilter-name>
<url-pattern>/*url-pattern>
filter-mapping>
第三种（修改tomcat中的配置，在config文件夹下的server.xml文件中）
<Connector URIEncoding="utf-8" port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
第四种解决方法（自定义过滤器）
package com.kuang.filter;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.Map;
/**
* 解决get和post请求 全部乱码的过滤器
*/
public class GenericEncodingFilter implements Filter {
@Override
public void destroy() {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
//处理response的字符编码
HttpServletResponse myResponse=(HttpServletResponse) response;
myResponse.setContentType("text/html;charset=UTF-8");
// 转型为与协议相关对象
HttpServletRequest httpServletRequest = (HttpServletRequest) request;
// 对request包装增强
HttpServletRequest myrequest = new MyRequest(httpServletRequest);
chain.doFilter(myrequest, response);
}
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
}
//自定义request对象，HttpServletRequest的包装类
class MyRequest extends HttpServletRequestWrapper {
private HttpServletRequest request;
//是否编码的标记
private boolean hasEncode;
//定义一个可以传入HttpServletRequest对象的构造函数，以便对其进行装饰
public MyRequest(HttpServletRequest request) {
super(request);// super必须写
this.request = request;
}
// 对需要增强方法 进行覆盖
@Override
public Map getParameterMap() {
// 先获得请求方式
String method = request.getMethod();
if (method.equalsIgnoreCase("post")) {
// post请求
try {
// 处理post乱码
request.setCharacterEncoding("utf-8");
return request.getParameterMap();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
} else if (method.equalsIgnoreCase("get")) {
// get请求
Map<String, String[]> parameterMap = request.getParameterMap();
if (!hasEncode) { // 确保get手动编码逻辑只运行一次
for (String parameterName : parameterMap.keySet()) {
String[] values = parameterMap.get(parameterName);
if (values != null) {
for (int i = 0; i < values.length; i++) {
try {
// 处理get乱码
values[i] = new String(values[i]
.getBytes("ISO-8859-1"), "utf-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
}
}
}
hasEncode = true;
}
return parameterMap;
}
return super.getParameterMap();
}
//取一个值
@Override
public String getParameter(String name) {
Map<String, String[]> parameterMap = getParameterMap();
String[] values = parameterMap.get(name);
if (values == null) {
return null;
}
return values[0]; // 取回参数的第一个值
}
//取所有值
@Override
public String[] getParameterValues(String name) {
Map<String, String[]> parameterMap = getParameterMap();
String[] values = parameterMap.get(name);
return values;
}
}
2、什么是json
- 是一种轻量级的数据的交换格式，目前使用特别的广泛
- 采用完全独立与编程语言的文本格式来存储和表示数据
- 简介和清晰的层次结构使得JSON成为理想的数交换语言
- 易与人的阅读和编写，同时也易于机器解析和生成，并有效的提升网络传输效率
JSON键值对是用来保存javaScript对象的一种方式，和JavaScript对象的写法也大同小异，键值对组合中的键名写在前面，并用双引号""进行包裹，使用冒号进行分割，紧接着便是值
例：
{“name”:“lisi”}、{“age”:“3”}、{“sex”,“男”}
JSON 和 JavaScript 对象互转
-
要实现从JSON字符串转换为JavaScript 对象，使用 JSON.parse() 方法：
var obj = JSON.parse('{"a": "Hello", "b": "World"}'); -
要实现从JavaScript 对象转换为JSON字符串，使用 JSON.stringify() 方法：
var json = JSON.stringify({a: 'Hello', b: 'World'});
2.1、json的使用
常用有三种json解析jackson、fastjson、gson。
jackson转化json需要的maven依赖
<dependency>
<groupId>com.fasterxml.jackson.coregroupId>
<artifactId>jackson-databindartifactId>
<version>2.9.3version>
dependency>
<dependency>
<groupId>com.fasterxml.jackson.coregroupId>
<artifactId>jackson-coreartifactId>
<version>2.9.3version>
dependency>
<dependency>
<groupId>com.fasterxml.jackson.coregroupId>
<artifactId>jackson-annotationsartifactId>
<version>2.9.3version>
dependency>
fastjson转化json需要的maven依赖
<dependency>
<groupId>com.alibabagroupId>
<artifactId>fastjsonartifactId>
<version>1.2.47version>
gson转化json需要的maven依赖
<dependency>
<groupId>com.google.code.gsongroupId>
<artifactId>gsonartifactId>
<version>2.8.2version>
dependency>
2.2、解决json的乱码问题
第一中方式 在@RequestMapping(value = “/t1”, produces=“text/html; charset=utf-8”)
@Controller
//@RestController 采用@RestController与@ResponseBody 都是直接跳过视图层，将数据之恶传送到前端
public class UserJson {
// produces="text/html; charset=utf-8"解决json的乱码问题
@RequestMapping(value = "/t1", produces="text/html; charset=utf-8")
@ResponseBody //当使用@ResponseBody方法会直接跳过视图层，之后将数据直接放回给页面
public String userJson( HttpServletResponse response) throws JsonProcessingException {
response.setCharacterEncoding("utf-8");
User user = new User("安帅", "女", "23");
ObjectMapper map=new ObjectMapper();
// 将对象转化为json字符串
String s = map.writeValueAsString(user);
System.out.println(user.toString());
System.out.println("========================="+s);
return s;
}
第二中方式（在zpringMVc-servlet.xml中配置文件）
<mvc:annotation-driven>
<mvc:message-converters register-defaults="true">
<bean class="org.springframework.http.converter.StringHttpMessageConverter">
<constructor-arg value="UTF-8"/>
bean>
<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="objectMapper">
<bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
<property name="failOnEmptyBeans" value="false"/>
bean>
property>
bean>
mvc:message-converters>
mvc:annotation-driven>
3、整合SSM
所需要的maven依赖
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<parent>
<artifactId>SpringMVCartifactId>
<groupId>org.examplegroupId>
<version>1.0-SNAPSHOTversion>
parent>
<modelVersion>4.0.0modelVersion>
<artifactId>SSM-SpringMVCartifactId>
<properties>
<maven.compiler.source>9maven.compiler.source>
<maven.compiler.target>9maven.compiler.target>
properties>
<dependencies>
<dependency>
<groupId>junitgroupId>
<artifactId>junitartifactId>
<version>4.13version>
<scope>testscope>
dependency>
<dependency>
<groupId>org.projectlombokgroupId>
<artifactId>lombokartifactId>
<version>1.16.10version>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<version>8.0.27version>
dependency>
<dependency>
<groupId>com.mchangegroupId>
<artifactId>c3p0artifactId>
<version>0.9.5.5version>
dependency>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>servlet-apiartifactId>
<version>2.5version>
dependency>
<dependency>
<groupId>javax.servlet.jspgroupId>
<artifactId>jsp-apiartifactId>
<version>2.2.1-b03version>
dependency>
<dependency>
<groupId>jstlgroupId>
<artifactId>jstlartifactId>
<version>1.2version>
dependency>
<dependency>
<groupId>org.mybatisgroupId>
<artifactId>mybatisartifactId>
<version>3.5.7version>
dependency>
<dependency>
<groupId>org.mybatisgroupId>
<artifactId>mybatis-springartifactId>
<version>2.0.6version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-webmvcartifactId>
<version>5.3.12version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-jdbcartifactId>
<version>5.3.13version>
dependency>
dependencies>
<build>
<resources>
<resource>
<directory>src/main/javadirectory>
<includes>
<include>**/*.propertiesinclude>
<include>**/*.xmlinclude>
includes>
<filtering>falsefiltering>
resource>
<resource>
<directory>src/main/resourcesdirectory>
<includes>
<include>**/*.propertiesinclude>
<include>**/*.xmlinclude>
includes>
<filtering>falsefiltering>
resource>
resources>
build>
project>
所创建的xml文件
-
springMVC所需要的配置文件
-
web.xml文件
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" version="4.0"> <welcome-file-list> <welcome-file>index.jspwelcome-file> welcome-file-list> <servlet> <servlet-name>DispatcherServletngservlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class> <init-param> <param-name>contextConfigLocationparam-name> <param-value>classpath:applicationContext.xmlparam-value> init-param> <load-on-startup>1load-on-startup> servlet> <servlet-mapping> <servlet-name>DispatcherServletngservlet-name> <url-pattern>/url-pattern> servlet-mapping> <filter> <description>字符集过滤器description> <filter-name>encodingFilterfilter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilterfilter-class> <init-param> <param-name>encodingparam-name> <param-value>UTF-8param-value> init-param> <init-param> <param-name>forceEncodingparam-name> <param-value>trueparam-value> init-param> filter> <filter-mapping> <filter-name>encodingFilterfilter-name> <url-pattern>/*url-pattern> filter-mapping> web-app> -
springMVC-servlet
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <context:component-scan base-package="com.li.inspur.Controller" /> <mvc:default-servlet-handler/> <mvc:annotation-driven/> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver"> <property name="prefix" value="/WEB-INF/jsp/"/> <property name="suffix" value=".jsp"/> bean> beans>
-
-
mybatis需要的配置文件
-
mybatis-config.xml
DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> <typeAliases> <package name="com.li.inspur.pojo"/> typeAliases> <mappers> <package name="com.li.inspur.mapper"/> mappers> configuration> -
db.properties
jdbc.driver=com.mysql.cj.jdbc.Driver jdbc.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT%2B8&useSSL=false jdbc.username=root jdbc.password=
-
-
spring中所需要的配置文件
-
mybatis-dao.xml
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd"> <context:property-placeholder location="classpath:db.properties"/> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="driverClass" value="${jdbc.driver}"/> <property name="jdbcUrl" value="${jdbc.url}"/> <property name="user" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> bean> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource" /> <property name="configLocation" value="classpath:mybatis-config.xml"/> bean> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/> <property name="basePackage" value="com.li.inspur.mapper"/> bean> beans> -
spring-service
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd"> <import resource="classpath:spring-dao.xml"/> <context:annotation-config/> <context:component-scan base-package="com.li.inspur.service" /> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"/> bean> beans> -
applicationContext.xml
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd"> <context:annotation-config/> <import resource="classpath:spring-dao.xml"/> <import resource="classpath:springmvc-servlet.xml"/> <import resource="spring-service.xml"/> beans>
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注：在ssm整合之中，applicationContext.xml文件时用来整合的，所以在web.xml在引进xml文件的时候，引进的时applicationContext.xml文件
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在整合ssm框架的时候注意mybatis-spring引进的maven依赖的版本的对应关系
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在使用mapper.xml文件的时候，不要忘记其文件的工作空间，以及各个文件之间的扫描
4、拦截器
4.1、定义
SpringMVC中的处理器拦截器类似于Servlet开发中的过滤器filter，用于对处理器进行预处理和后处理，开发者可以自己定义一些拦截器来实现一些特定的功能
过滤器与拦截器的区别
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拦截器时AOP的思想
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过滤器，servlet规范中的一部分，任何Javaweb项目都可以使用，在url-pattern中配置了/*之后，便可以对所有的资源进行拦截
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注：拦截器是SpringMVC框架自己的，只有使用了SpringMVC框架才可以使用
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拦截器只会拦截访问的控制器方法，如果访问的是jsp/html/css/image/js是不会进行拦截的
自定义拦截器
实现HandlerInterceptor接口
自定义拦截器
package com.li.inspur.until;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//设置自定义拦截器
public class interceptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
// 表示在执行前进行拦截，当返回值是true时，表示通过所有的请求
System.out.println("执行之前");
return false;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
// 表示在执行完成之后进行拦截
System.out.println("执行之后");
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
// 在执行之后做处理工作
System.out.println("表示在执行之后做处理工作");
}
}
在SpringMVC配置拦截器
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/**"/>
<bean class="com.li.inspur.until.interceptor"/>
mvc:interceptor>
mvc:interceptors>
5、SpringMVC中的文件的上传和下载
所需要的maven依赖
<dependency>
<groupId>commons-fileuploadgroupId>
<artifactId>commons-fileuploadartifactId>
<version>1.4version>
dependency>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>javax.servlet-apiartifactId>
<version>4.0.1version>
dependency>
springMVC.xml中的文件的配置
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="defaultEncoding" value="utf-8"/>
<property name="maxUploadSize" value="10485760"/>
<property name="maxInMemorySize" value="40960"/>
bean>
package com.li.inspur.Controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.commons.CommonsMultipartFile;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;
@Controller
@RequestMapping(value = "/user")
public class toLoad {
//@RequestParam("file") 将name=file控件得到的文件封装成CommonsMultipartFile 对象
//批量上传CommonsMultipartFile则为数组即可
//文件的上传
@RequestMapping(value = "/upload")
public String fileUpload(@RequestParam("file") CommonsMultipartFile file , HttpServletRequest request) throws IOException {
System.out.println("调用了这个方法");
//获取文件名 : file.getOriginalFilename();
String uploadFileName = file.getOriginalFilename();
//如果文件名为空，直接回到首页！
if ("".equals(uploadFileName)){
return "redirect:/index.jsp";
}
System.out.println("上传文件名 : "+uploadFileName);
//上传路径保存设置
String path = request.getServletContext().getRealPath("/upload");
//如果路径不存在，创建一个
File realPath = new File(path);
if (!realPath.exists()){
realPath.mkdir();
}
System.out.println("上传文件保存地址："+realPath);
InputStream is = file.getInputStream(); //文件输入流
OutputStream os = new FileOutputStream(new File(realPath,uploadFileName)); //文件输出流
//读取写出
int len=0;
byte[] buffer = new byte[1024];
while ((len=is.read(buffer))!=-1){
os.write(buffer,0,len);
os.flush();
}
os.close();
is.close();
return "redirect:/index.jsp";
}
//文件的的下载
@RequestMapping(value="/download")
public String downloads(HttpServletResponse response , HttpServletRequest request) throws Exception{
System.out.println("调用了文件的下载的方法");
//要下载的图片地址
String path = request.getServletContext().getRealPath("/upload");
String fileName = "timg.jpg";
//1、设置response 响应头
response.reset(); //设置页面不缓存,清空buffer
response.setCharacterEncoding("UTF-8"); //字符编码
response.setContentType("multipart/form-data"); //二进制传输数据
//设置响应头
response.setHeader("Content-Disposition",
"attachment;fileName="+ URLEncoder.encode(fileName, "UTF-8"));
File file = new File(path,fileName);
//2、 读取文件--输入流
InputStream input=new FileInputStream(file);
//3、 写出文件--输出流
OutputStream out = response.getOutputStream();
byte[] buff =new byte[1024];
int index=0;
//4、执行 写出操作
while((index= input.read(buff))!= -1){
out.write(buff, 0, index);
out.flush();
}
out.close();
input.close();
return null;
}
}
nloads(HttpServletResponse response , HttpServletRequest request) throws Exception{
System.out.println(“调用了文件的下载的方法”);
//要下载的图片地址
String path = request.getServletContext().getRealPath("/upload");
String fileName = “timg.jpg”;
//1、设置response 响应头
response.reset(); //设置页面不缓存,清空buffer
response.setCharacterEncoding("UTF-8"); //字符编码
response.setContentType("multipart/form-data"); //二进制传输数据
//设置响应头
response.setHeader("Content-Disposition",
"attachment;fileName="+ URLEncoder.encode(fileName, "UTF-8"));
File file = new File(path,fileName);
//2、 读取文件--输入流
InputStream input=new FileInputStream(file);
//3、 写出文件--输出流
OutputStream out = response.getOutputStream();
byte[] buff =new byte[1024];
int index=0;
//4、执行 写出操作
while((index= input.read(buff))!= -1){
out.write(buff, 0, index);
out.flush();
}
out.close();
input.close();
return null;
}
}