longin.html：登录页面，此处action引用**/**类型的地址，JSP可以用${ pageContext.request.contextPath }/LS

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
                           "http://www.w3/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
  <body>
    <form action="/lianxiti/LS"，method="post">
    	
	    用户名: <input name="username" type="text" /><br/>
		密码：<input name="password" type="password" /><br/>	
			    <input type="submit" value="提交" id="bt" />
    </form>
  </body>

LoginServlet.java用户和前台WEB页面数据进行交互

package it.tongyou.web.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 LoginServlet extends HttpServlet {
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
	//乱码解决
	response.setContentType("text/html;charset-utf-8");
	//获取页面传过来的数据
	String username=request.getParameter("username");
	String password=request.getParameter("password");
	//判断账号密码
	if(("xm").equals(username) && ("123").equals(password)){
		response.sendRedirect("/lianxiti/success.html");
	}else{
		response.sendRedirect("/liantixi/longin.html");
	}
	}
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request, response);
	}
}

web.xml应用路径配置/LS和longin.html引用地址一定要一样，因为此处需要把WEB页面的数据提交到对应的servlet中；

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
	xmlns="http://java.sun/xml/ns/javaee" 
	xmlns:xsi="http://www.w3/2001/XMLSchema-instance" 
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  
  <!-- 页面WEB跳转servlet层 -->
  <servlet>
    <servlet-name>LoginServlet</servlet-name>
    <servlet-class>it.tongyou.web.servlet.LoginServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>LoginServlet</servlet-name>
    <url-pattern>/LS</url-pattern>
  </servlet-mapping>

 <!-- 打开项目优先展示页面 --> 
  <welcome-file-list>
    <welcome-file>longin.html</welcome-file>
  </welcome-file-list>
</web-app>

成功后跳到success.html页面

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
                           "http://www.w3/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
  <body>
    成功登录
  </body>
</html>

更多推荐

简单WEB登录页面代码实现