springmvc的简单登录功能

来源：互联网发布：哈工大gpa算法编辑：程序博客网时间：2024/06/06 19:24

与其它web MVC框架一样，Spring的web MVC框架是一个请求驱动的web框架，其设计围绕一个中心的servlet进行，它能将请求分发给控制器，并提供其它功能帮助web应用开发。然而，Spring的DispatcherServlet所做的不仅仅是这些，它和Spring的IoC容器完全集成在一起，从而允许你使用Spring的其它功能。

下图展示了Spring Web MVC DispatcherServlet处理请求的流程。熟悉设计模式的读者可能会发现DispatcherServlet应用了“ Front Controller”模式（很多其他的主流web框架也都用到了该模式）。

注:

Front Controller - 前端控制器 ;

Delegate request: 委托请求 ;

rendering of response :呈现响应 ;

servlet engine ：servlet引擎

　　　　　　　　　　　　　　　　　　　　　　　　Spring Web MVC DispatcherServlet请求处理流程

1.新建web项目。导入spring2.5jar包。采用tomcat6+jdk1.6启动项目。

2.web.xml配置DispatcherServlet

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<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>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>

3.web中加载的applicationContext.xml文件内容如下:

<?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:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans-2.5.xsd">


<bean id="urlMappging" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
  <property name="mappings">
    <props>
     <prop key="/login.do">loginController</prop>
    </props>
  </property>
</bean>

<bean id="loginController" class="com.pb.web.controller.LoginController">
<property name="fromView" value="login"/>
<property name="successView" value="showAccount"/>
</bean>

<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/"></property>
<property name="suffix" value=".jsp"/>
</bean>
</beans>

3.com.pb.web.controller.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 fromView="";
private String successView="";
@Override
protected ModelAndView handleRequestInternal(HttpServletRequest request,
   HttpServletResponse response) throws Exception {

  //1.获取账户和密码
  String cardNo = request.getParameter("cardNo");
  String password = request.getParameter("password");
  //2.调用业务逻辑层代码判断，在这里弱化controller的处理直接在controller里进行业务判断
  Account account = getAccount(cardNo, password);
  //3.根据结果返回不同的modelandview
  Map<String,Object> model = new HashMap<String,Object>();
  if(account!=null){
   model.put("account", account);
   return new ModelAndView(getSuccessView(),model);
  }else{
   model.put("message", "用户名密码错误!");
   return new ModelAndView(getFromView(),model);
  }
}

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;
  }
  return null;
}

public String getFromView() {
  return fromView;
}

public void setFromView(String fromView) {
this.fromView = fromView;
}

public void setSuccessView(String successView) {
this.successView = successView;
}

public String getSuccessView() {
return successView;
}

public void setFromview(String successView) {
this.successView = successView;
}

}

4.login.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
    <base href="<%=basePath%>">

    <title>登录</title>

<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">

</head>

<body>
${message}
    <form action="login.do" method="post">

    卡号:<input type="text" name="cardNo" value=""/><br/>
    密码:<input type="password" name="password" value=""/><br/>
    <button type="submit">submit</button>
    </form>
</body>
</html>

5.showAccount.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8" contentType="text/html; charset=utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
    <base href="<%=basePath%>">

    <title>My JSP 'showAccount.jsp' starting page</title>

<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">

</head>

<body>
卡号:${account.cardNo} <br/>
余额:${account.balance }<br/>
</body>
</html>

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