【转载】SpringMVC框架介绍

转自：http://com-xpp.iteye.com/blog/1604183

SpringMVC框架图

 

SpringMVC接口解释

 

 

DispatcherServlet接口：

 

Spring提供的前端控制器，所有的请求都有经过它来统一分发。在DispatcherServlet将请求分发给Spring Controller之前，需要借助于Spring提供的HandlerMapping定位到具体的Controller。

 

HandlerMapping接口：

 

能够完成客户请求到Controller映射。

 

Controller接口：

 

需要为并发用户处理上述请求，因此实现Controller接口时，必须保证线程安全并且可重用。Controller将处理用户请求，这和Struts Action扮演的角色是一致的。一旦Controller处理完用户请求，则返回ModelAndView对象给DispatcherServlet前端控制器，ModelAndView中包含了模型（Model）和视图（View）。从宏观角度考虑，DispatcherServlet是整个Web应用的控制器；从微观考虑，Controller是单个Http请求处理过程中的控制器，而ModelAndView是Http请求过程中返回的模型（Model）和视图（View）。

 

ViewResolver接口：

 

Spring提供的视图解析器（ViewResolver）在Web应用中查找View对象，从而将相应结果渲染给客户。

 

SpringMVC运行原理

 

1.客户端请求提交到DispatcherServlet

2.由DispatcherServlet控制器查询一个或多个HandlerMapping，找到处理请求的Controller

3.DispatcherServlet将请求提交到Controller

4.Controller调用业务逻辑处理后，返回ModelAndView

5.DispatcherServlet查询一个或多个ViewResoler视图解析器，找到ModelAndView指定的视图

6.视图负责将结果显示到客户端

 

SpringMVC运行实例

Account类：

 

package com.pb.entity;

public class Account {
    private String cardNo;
    private String password;
    private float balance;
    public String getCardNo() {
        return cardNo;
    }
    public void setCardNo(String cardNo) {
        this.cardNo = cardNo;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public float getBalance() {
        return balance;
    }
    public void setBalance(float balance) {
        this.balance = balance;
    }

}

 

LoginController类：

 

package com.pb.web.controller;

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;

import com.pb.entity.Account;

public class LoginController extends AbstractController {
    private String successView;
    private String failView;//这两个参数是返回值传给applicationContext.xml，进行页面分配

    public String getSuccessView() {
        return successView;
    }
    public void setSuccessView(String successView) {
        this.successView = successView;
    }
    public String getFailView() {
        return failView;
    }
    public void setFailView(String failView) {
        this.failView = failView;
    }
    @Override
    protected ModelAndView handleRequestInternal(HttpServletRequest request,
            HttpServletResponse response) throws Exception {
        // TODO Auto-generated method stub
        String cardNo=request.getParameter("cardNo");
        String password=request.getParameter("password");
        Account account =getAccount(cardNo,password);
        Map<String ,Object> model=new HashMap<String,Object>();
        if(account !=null){
            model.put("account", account);
            return new ModelAndView(getSuccessView(),model);
        }else{
            model.put("error", "卡号和密码不正确");
            return new ModelAndView(getFailView(),model);
        }
    }//本应该这个方法写在模型层，这地方直接给放在了逻辑层这个地方偷懒了。
    public Account getAccount(String cardNo,String password){
        if(cardNo.equals("123")&&password.equals("123")){
            Account account =new Account();
            account.setCardNo(cardNo);
            account.setBalance(88.8f);
            return account;
        }else{
            return null;
        }
    }

}

applicationContext.xml

 

 

<?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:aop="http://www.springframework.org/schema/aop"
         xmlns:tx="http://www.springframework.org/schema/tx"
         xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
           http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
           http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd">
    <bean id="loginController" class="com.pb.web.controller.LoginController">
        <property name="successView" value="showAccount"></property>
        <property name="failView" value="login"></property>
    </bean>
    <bean id="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
        <property name="mappings">
            <props>
                <prop key="/login.do">loginController</prop>
            </props>
        </property>
    </bean>
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>
</beans>

Jsp页面：

 

<%@ page language="java" contentType="text/html; charset=GB18030"
    pageEncoding="GB18030"%>
<!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=GB18030">
<title>Insert title here</title>
</head>
<body>
    <a href="login.jsp">进入</a>

</body>
</html>

login.jsp

 

 

<%@ page language="java" contentType="text/html; charset=GB18030"
    pageEncoding="GB18030"%>
<!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=GB18030">
<title>Insert title here</title>
</head>
<body>
${error }
    <form action="login.do" method="post">
        账号登陆<br>
        <hr>
        卡号：<input type="text" name="cardNo"><br>
        密码：<input type="text" name="password"><br>
        <input type="submit" value="登陆">
    </form>

</body>
</html>

showAccount.jsp

 

 

<%@ page language="java" contentType="text/html; charset=GB18030"
    pageEncoding="GB18030"%>
<!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=GB18030">
<title>Insert title here</title>
</head>
<body>
    账户信息<br>
    卡号：${account.cardNo }<br>
    密码：${account.password }<br>
    钱数：${account.balance }<br>
</body>
</html>

Web.xml

<?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/j2ee"
            xmlns:javaee="http://java.sun.com/xml/ns/javaee"
            xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" version="2.4">
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
    <servlet-name>Dispatcher</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>Dispatcher</servlet-name>
    <url-pattern>*.do</url-pattern>
  </servlet-mapping>
</web-app>