Java Web Session 登录范例 _Web前端

Java Web Session 登录实例
package cn.com.login;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;

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


public class Login extends HttpServlet {
	private static final long serialVersionUID = 1L;
   
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		response.setCharacterEncoding("UTF-8");
		response.setContentType("text/html;charset=UTF-8");
		
		String userName=request.getParameter("userName");
		String password=request.getParameter("password");
		PrintWriter out=response.getWriter();
		
		List<User> list=Db.getAll();
		for(User user:list)
		{
			if(user.getUserName().equals(userName)&&user.getPassword().equals(password))
			{
				request.getSession().setAttribute("user", user);
				response.sendRedirect("/Session/index.jsp");
				return ;
			}
			
		}
		out.write("用户名或者密码错误！");
		
	}

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

}
class Db
{
	public static List<User> list=new ArrayList();
	static
	{
		list.add(new User("aaa","123"));
		list.add(new User("bbb","123"));
		list.add(new User("ccc","123"));
	}
	public static List<User> getAll()
	{
		return list;
	}
}
package cn.com.login;

public class User {
	
	private String userName;
	private String password;
	
	public User() {
		super();
		// TODO Auto-generated constructor stub
	}
	public User(String userName, String password) {
		super();
		this.userName = userName;
		this.password = password;
	}
	public String getUserName() {
		return userName;
	}
	public void setUserName(String userName) {
		this.userName = userName;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	

}
package cn.com.login;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * Servlet implementation class LogOut
 */
public class LogOut extends HttpServlet {
	private static final long serialVersionUID = 1L;

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		HttpSession session=request.getSession(false);
		if(session==null)
		{
			response.sendRedirect("/Session/index.jsp");
			return ;
		}
		session.removeAttribute("user");
		response.sendRedirect("/Session/index.jsp");
	}

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

}
<!DOCTYPE html>
<html>
  <head>
    <title>Index.html</title>
	
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="this is my page">
    <meta http-equiv="content-type" content="text/html; charset=UTF-8">
    
    <!--<link rel="stylesheet" type="text/css" href="./styles.css">-->

  </head>
  
  <body>
  	
  <form action="/Session/Login">
  	
  	用户名：<input type="text" name="userName"/><br/>
  	密码：<input type="password" name="password"/><br/>
  	<input type="submit" value="登录" name="login"/>
  </form>
    	
  </body>
</html>