servlet实现控制台输出用户名和密码的相关步骤和代码

最新推荐文章于 2023-05-19 10:01:49 发布

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#servlet #控制台

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这篇博客介绍了如何通过Servlet在控制台显示从JSP页面获取的用户名和密码。首先创建ServletDemo1，通过GET请求获取参数并打印；然后创建Index.jsp页面，设置超链接传递用户名和密码至ServletDemo2进行输出；最后，创建用户登录表单JSP，提交后由ServletDemo3处理并打印用户信息。

1、创建一个servlet，命名ServletDemo1，在浏览中访问该servlet

代码如下：
package servlet;
import java.io.IOException;
import java.io.PrintWriter;

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

public class ServletDemo1 extends HttpServlet {

/**
* Constructor of the object.
*/
public ServletDemo1() {
super();
}

/**
* Destruction of the servlet. 
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}

/**
* The doGet method of the servlet. 
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
 throws ServletException, IOException {
 String mes=request.getParameter("mes");
 System.out.print(mes);
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
}

/**
* Initialization of the servlet. 

* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}

}
2、创建一个带超链接的jsp页面，超链接到ServletDemo2,在控制台输出jsp页面通过超链接参数传递的用户名和密码。
Index.jsp 代码参考
<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%>
<%
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 'index.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>
 <a href="/ZY/ServletDemo2?name=zy&&pass=123">hahhahahhahaha</a>
</body>
</html>
</html>

SevletDemo2.java 代码参考
package servlet;

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

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

public class ServletDemo2 extends HttpServlet {

/**
* Constructor of the object.
*/
public ServletDemo2() {
super();
}

/**
* Destruction of the servlet. 
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}

/**
* The doGet method of the servlet. 
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
 throws ServletException, IOException {
 String name=request.getParameter("name");
 String pass=request.getParameter("pass");
 System.out.println("用户名:"+name);
 System.out.println("密码:"+pass);
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
}

/**
* Initialization of the servlet. 
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}

}
3、创建一个用户登录的jsp页面，用户在表单中输入用户名和密码，提交后跳转到ServletDemo3，在控制台输出用户名和密码。