目录结构：
contents structure [+]
SpringMVC是什么
MVC的全称是Model View Controller，通过实现MVC框架可以很好的数据、视图、业务逻辑进行分离。Spring MVC也是一种MVC框架，它是SpringFrameWork的后续产品，同样需要Spring的Jar包才能运行起来。
SpringMVC的设计原理
Spring MVC的设计是围绕着DispatcherServlet展开的，由DispatcherServlet将请求派发到特定的Controller。
下面是SpringMVC的一个简单流程图：
SpringMVC配置第一种方式
我的项目结构：
1，复制Jar包
将Spring的Jar包复制到lib目录下。
2，Web.xml文件
配置Web.xml文件
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"> <!-- this name matched project name --> <display-name>SpringMVC</display-name> <!-- transmit to dispacherServlet to deal with information that passed from table servlet-mapping --> <servlet> <servlet-name>mySpring</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>mySpring</servlet-name> <url-pattern>*.ms</url-pattern> </servlet-mapping> <!-- solve messy code --> <filter> <filter-name>encodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>UTF-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>encodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </web-app>
3，mySpring-servlet.xml文件
在工程的WEB-INF下面创建dispatcherServlet配置文件[servlet-name]-servlet.xml。
文件名的格式必需为“[servlet-name]-servlet.xml”，比如笔者的web文件里servlet-name为mySpring，则文件名必须为mySpring-servlet.xml，如果放错的位置或是文件名称格式不对，那么通过web.xml文件是找不到dispatcherServlet文件的。也可以说，只要在Web.xml里配置好了DispatcherServlet，那么该DispatcherServlet的名称也就唯一确定了，一个web.xml文件可以映射出多个DispatcherServlet文件。
<?xml version="1.0" encoding="UTF-8"?> <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:jdbc="http://www.springframework.org/schema/jdbc" xmlns:jee="http://www.springframework.org/schema/jee" xsi:schemaLocation="http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-4.3.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-4.3.xsd 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-4.3.xsd"> <!-- configure HandlerMapping --> <bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"></bean> <!-- configure HandlerAdapter --> <bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"></bean> <!-- configure controller --> <bean name="/testSpring.ms" class="com.my.spring.TestSpring"></bean> <!-- configure viewResolver --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass"> <value>org.springframework.web.servlet.view.InternalResourceView</value> </property> <property name="prefix" value="/view/"></property> <property name="suffix" value=".jsp"></property> </bean> </beans>
4，welcome.jsp文件
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>Insert title here</title> </head> <body> <form action="testSpring.ms"> input your words: <input type="text" name="words"/> <input type="submit" value="提交"> </form> </body> </html>
5，result.jsp文件
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>Insert title here</title> </head> <body> ${myValue} </body> </html>
6，TestSpring.java文件
package com.my.spring; import java.util.HashMap; import java.util.Map; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.mvc.AbstractController; public class TestSpring extends AbstractController { @Override protected ModelAndView handleRequestInternal(HttpServletRequest request, HttpServletResponse response) throws Exception { // TODO Auto-generated method stub String value=request.getParameter("words"); //create model Map<String,String>model=new HashMap<String,String>(); //set value model.put("myValue", value); //create modelAndView ModelAndView mav=new ModelAndView("result",model); return mav; } }
这个文件必需要实现AbstrcactController抽象类，或是实现Controller接口。然后重写handlerRequestInternal方法。这里一定要选择servlet下的AbstractController或Controller，如果读者选择了portlet，恰好项目下又没有相应的包，那么就会报错。
错误
一，错误一：
错误代码：
The superclass "javax.servlet.http.HttpServlet" was not found on the Java Build Path
错误解决：
这是因为项目下没有该类，添加servlet-api.jar即可，详见Eclipse如何发布Web项目。
二，错误二：
错误代码：
Server Tomcat v8.5 Server at localhost failed to start.
错误解决：
造成这个错误的原因有许多，这里建议读者检查一下自己的Web.xml文件中的语法是否正确。
三，错误三：
错误代码：
Multiple markers at this line
- The type javax.portlet.ActionResponse cannot be resolved. It is indirectly
referenced from required .class files
- The type javax.portlet.RenderRequest cannot be resolved. It is indirectly
referenced from required .class files
- The type javax.portlet.RenderResponse cannot be resolved. It is indirectly
referenced from required .class files
- The type javax.portlet.ActionRequest cannot be resolved. It is indirectly
referenced from required .class files
- The type javax.portlet.PortletContext cannot be resolved. It is indirectly referenced
from required .class files
问题解决：
这是因为读者的项目下面没有，portlet包导致的，portlet包的下载。
除了引入相应的Portlet包外，这里读者也可以将
import org.springframework.web.portlet.ModelAndView; import org.springframework.web.portlet.mvc.AbstractController;
改为：
import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.mvc.AbstractController;
四，错误四：
错误代码：
Handler processing failed; nested exception is java.lang.NoClassDefFoundError: javax/servlet/jsp/jstl/core/Config
错误解决：
导入一个jstl标签库即可，下载一个标签标准文档库下载页面。
SpringMVC配置的第二种方式
这种方式和上面的方式都是非注解的方式，两者的区别就是使用的类不同。
下面的配置方式和上面的配置方式是想通的：
来一张目录结构：
applicationContext.xml文件
<?xml version="1.0" encoding="UTF-8"?> <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:jdbc="http://www.springframework.org/schema/jdbc" xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:util="http://www.springframework.org/schema/util" xmlns:jpa="http://www.springframework.org/schema/data/jpa" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-4.1.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-4.1.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.1.xsd http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.1.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.1.xsd"> <bean id="helloController" class="cn.xdl.controller.HelloController"></bean> <bean id="handlerMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping"> <property name="mappings"> <props> <!-- key: 请求的url地址 value: 自己编写的控制器(Controller实现类)在容器中对象的id 起到的作用, 将一个url地址, 绑定一个控制器 ,当匹配这个url的请求发生时, 入口Servlet自动调用这个控制器对象, 并将请求对象与响应对象转递过来 --> <prop key="/hello.do">helloController</prop> </props> </property> </bean> <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <!-- 解析modelAndView的工具 例如我们返回了一个ModelAndView ., 封装了一个视图name为: hello 解析完毕后: perfix+hello+suffix 转发至:/hello.jsp --> <property name="prefix" value="/"></property> <property name="suffix" value=".jsp"></property> </bean> </beans>
web.xml文件
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0"> <display-name>day04_WebMvc</display-name> <welcome-file-list> <welcome-file>index.html</welcome-file> <welcome-file>index.htm</welcome-file> <welcome-file>index.jsp</welcome-file> <welcome-file>default.html</welcome-file> <welcome-file>default.htm</welcome-file> <welcome-file>default.jsp</welcome-file> </welcome-file-list> <!-- 如果不需要使用 ini-param 对web配置文件指明SpringMVC的配置文件的地址，那么SpringMVC的配置文件必须放到WEB-INFO目录下，并且命名为[Servlet-name]-servlet.xml。 --> <servlet> <servlet-name>dispatcherServlet</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:applicationContext.xml</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>dispatcherServlet</servlet-name> <url-pattern>*.do</url-pattern> </servlet-mapping> </web-app>
HelloController.java文件
package cn.xdl.controller;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;
public class HelloController implements Controller {
@Override
public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception {
System.out.println("控制器正在执行");
System.out.println("调用响应的Dao进行操作");
System.out.println("根据结果, 返回不同的视图封装");
//modelandView 最少要传递一个View
ModelAndView mav = new ModelAndView();
mav.setViewName("hello");
//mav.getModel().put(key, value)
return mav;
}
}
除了实现Controller接口，也可以继承AbstractController 类。
hello.jsp文件
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Insert title here</title> </head> <body> 哈哈哈哈哈哈哈哈哈 </body> </html>
当然关于上面这两种方式，不一定经常用，关于使用注解比较多。使用注解的配置可以参加“SpringMVC之基于注解的实现SpringMVC+MySQL”