日期:2014-05-20  浏览次数:20684 次

实在不明白跳转失败,servlet,初学者 (via TranXcode)
看的韩的视频
基本写的都一样,从登录//Login,到验证//LoginCl,成功//Wel
Java code
 

package com.zgd;

import javax.servlet.*;
import java.io.*;
import javax.servlet.http.*;

public class Login extends HttpServlet {


// get
public void doGet(HttpServletRequest req,HttpServletResponse res){

System.out.println(" service ");

res.setContentType("text/html; charset=gbk");
try {
PrintWriter pw=res.getWriter();
pw.println(" <html>");
pw.println(" <title>");
pw.println("学生登录");
pw.println(" </title>");

pw.println(" <body>");

pw.println(" <H1>登录界面 </H1>");
pw.println(" <form action=LoginCl,method=post>");

pw.println("用户名: <input type=text name=username> <br>");

pw.println("密码: <input type=password name=passwd> <br>");

pw.println(" <input type=submit value=Login> <br> ");

pw.println(" </form>");


pw.println(" </body>");


pw.println(" </html>");
}

catch(Exception e){
e.printStackTrace();
}



}

public void doPost(HttpServletRequest req,HttpServletResponse res){

doGet(req,res);
}
}




Java code
 
package com.zgd;

import javax.servlet.*;
import java.io.*;
import javax.servlet.http.*;

public class LoginCl extends HttpServlet {


// get
public void doGet(HttpServletRequest req,HttpServletResponse res){
res.setContentType("text/html; charset=gbk");



try {

PrintWriter pw=res.getWriter();
pw.println(" <html> <body> <h1>你来到了 验证界面 </h1> </body> </html>");

String u=req.getParameter("username");
String p=req.getParameter("passwd");

if(u.equals("xll")&&p.equals("xll")){

res.sendRedirect("Wel");

} else {
res.sendRedirect("Login");//to URL
}

}

catch(Exception e){
e.printStackTrace();
}





}

public void doPost(HttpServletRequest req,HttpServletResponse res){

this.doGet(req,res);

}
}


Java code
 

package com.zgd;

import javax.servlet.*;
import java.io.*;

import javax.servlet.http.*;

public class Wel extends HttpServlet {

// get
public void doGet(HttpServletRequest req,HttpServletResponse res){

System.out.println(" service ");
try {
PrintWriter pw=res.getWriter();
pw.println("WEL COME ,U");
}

catch(Exception e){
e.printStackTrace();
}



}

public void doPost(HttpServletRequest req,HttpServletResponse res){

doGet(req,res);
}
}





web-xml
XML code