JSP和Server的相互转化

【设计想法】

【前置条件】

1. eclipse的web环境已经搭建OK

2. eclipse已经存在web项目“firstweb”

【操作步骤】

1. “firstweb”新建3个jsp文件，hello.jsp, success.jsp, fail.jsp文件

（1） hello.jsp

<%@ 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="<%=request.getContextPath()%>/test" method="post">
        <table>
            <tr>
                <td><label>用户名：</label></td>
                <td><input name="username" type="text"></td>
            </tr>
            <tr>
                <td><label>密码：</label></td>
                <td><input name="password" type="text"></td>
            </tr>
            <tr>
                <td><input name="sumbit" type="submit" value="Submit"></td>
                <td><input name="cancel" type="reset" value="Cancel"></td>

            </tr>
        </table>
    </form>
</body>
</html>

（2）success.jsp代码

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!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>
Sucess!
</body>
</html>

（3）fail.jsp代码

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!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>
 fail!
</body>
</html>

2. “firstweb”新建1个server文件，test.java
（1）test.java文件

package com;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.Writer;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class test
 */
public class test extends HttpServlet {
    private static final long serialVersionUID = 1L;
    PrintWriter pw = null;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public test() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doPost(request, response);
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        request.setCharacterEncoding("utf-8");
        String username = (String) request.getParameter("username");
        String password = (String)request.getParameter("password");
        
        RequestDispatcher rd1 = request.getRequestDispatcher("success.jsp");
        RequestDispatcher rd2 = request.getRequestDispatcher("fail.jsp");
        if(username.equalsIgnoreCase("test") && password.equalsIgnoreCase("test")) {
            rd1.forward(request, response);
        } else {
            rd2.forward(request, response);
        }

    }

}

3. web.xml中的配置如下：

<?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" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>firstweb</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>
  <servlet>
    <description></description>
    <display-name>test</display-name>
    <servlet-name>test</servlet-name>
    <servlet-class>com.test</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>test</servlet-name>
    <url-pattern>/test</url-pattern>
  </servlet-mapping>
</web-app>

4. 启动tomcat服务器

5. 运行返回正确的结果如下：

6. 运行返回正确的结果如下：