接上篇 MVC循序渐进(jsp model1实现的登录)
1、用jsp model1实现用户登录
（1）、eclipse菜单 File->New->Folder 文件夹名称 model2
（2）、新建jsp文件
webapp\WEB-INF\src\model2\LoginServlet.java (相对于eclipse目录结构)
webapp\model2\ login.jsp
webapp\model3\ succeed.jsp
webapp\WEB-INF\web.xml
（3）、
LoginServlet.java
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package model2;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.URLEncoder;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class LoginServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws IOException, ServletException {
process(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws IOException, ServletException {
process(request, response);
}
public void process(HttpServletRequest request, HttpServletResponse response)
throws IOException {
response.setContentType("text/html");
response.setCharacterEncoding("GBK");
PrintWriter out = response.getWriter();
boolean isSucceed = false;
String msg = "";
String username = request.getParameter("username");
String password = request.getParameter("password");
if (username != null) {
System.out.println("登陆处理开始.........");
username = username.trim();
password = password.trim();
if (username.equals("") && username.equals("")) {
isSucceed = false;
msg = "用户名或密码为空";
} else {
isSucceed = true;
}
if (isSucceed) {
if (username.equals("zkjbeyond")
&& password.equals("zkjbeyond")) {
isSucceed = true;
HttpSession session = request.getSession();
msg = "登陆成功";
session.setAttribute("username", username);
} else {
isSucceed = false;
msg = "用户名密码不正确";
}
}
} else {
isSucceed = false;
msg = "请输入用户名密码";
}
out.println(username);
System.out.println(msg + isSucceed);
System.out.println("登陆处理结束.........");
if (isSucceed) {
response.sendRedirect("succeed.jsp");
} else {
String url = "login.jsp?msg=" + URLEncoder.encode(msg, "GBK");
response.sendRedirect(url);
}
}
}
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login.jsp
*************************************
<%@ page language="java" pageEncoding="GB2312" %>
<%@ page import="java.net.URLDecoder"%>
<!DOCTYPE HTML PUBLIC "-//w3c//dtd html 4.0 transitional//en">
<html>
<head>
<title>login</title>
</head>
<%
request.setCharacterEncoding("GBK");
String msg=request.getParameter("msg");
if(msg!=null){
msg=URLDecoder.decode(msg,"GBK");
}else{
msg="";
}
%>
<body bgcolor="#FFFFFF">
<form action="LoginServlet" method="post">
<div>
<span style="width:70;">用户名：</span>
<span><input type="text" name="username"></span>
</div>
<div>
<span style="width:70;">密 码：</span>
<span><input type="password" name="password"></span>
</div>
<div>
<span style="width:70;"></span>
<span><input type="submit"></span>
</div>
<div style="color:red;">
<%
if(!msg.equals(""))
out.println(msg);
%>
</div>
</form>
</body>
</html>
******************************************
succeed.jsp
***************************************************
<%@ page language="java" pageEncoding="GB2312" %>
<!DOCTYPE HTML PUBLIC "-//w3c//dtd html 4.0 transitional//en">
<html>
<head>
<title>succeed</title>
</head>
<body bgcolor="#FFFFFF">
<%
Object username=session.getAttribute("username");
if(username!=null)
out.println("用户名为："+username);
else
response.sendRedirect("login.jsp");
%>
</body>
</html>
************************************************
web.xml
******************************************************
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE web-app
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd">
<web-app>
<display-name>Examples</display-name>
<description>Examples. </description>
<servlet>
<servlet-name>LoginServlet</servlet-name>
<servlet-class>model2.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/model2/LoginServlet</url-pattern>
</servlet-mapping>
</web-app>
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