SpringMVC框架介绍

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

Spring框架提供了构造Web应用程序的全能MVC模块。Spring MVC分离了控制器、模型对象、分派器以及处理程序对象的角色，这种分离让它们更容易进行制定。是一个标准的MVC框架。

 

那你猜一猜哪一部分应该是哪一部分？

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：

 

Java代码 
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：

 

Java代码 
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

 

 

Html代码 
<?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：

 

Html代码 
<%@ 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

 

 

Html代码 
<%@ 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

 

 

Html代码 
<%@ 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

Html代码 
<?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>