用户登陆系统服务器端(mysql存储)

package cn.com.xiebiao.tomcat;

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

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

/**
 *
 * Title  : LoginServlet.java
 * Company: ZhenBot
 * Author : Vibe Xie  @
 * Time   : Mar 7, 2015 4:25:46 PM
 * Copyright: Copyright (c) 2015
 *
 */

@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    private static Login service;
    public static int seviceTimes=0;
    @Override
    public void init() throws ServletException {
        // TODO Auto-generated method stub
        super.init();
        service=new Login();
    }

    /**
     * @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");
        response.setContentType("text/html;charset=utf-8");
        response.setCharacterEncoding("utf-8");

        System.out.println("servlet第"+(seviceTimes++)+"次服务");

        PrintWriter writer=response.getWriter();

        String clientName=request.getParameter("name");
        String clientPassword=request.getParameter("password");

        System.out.println("请求的name："+clientName);
        System.out.println("请求的password："+clientPassword);

        boolean flag=service.isUserLogin(clientName, clientPassword);

        if(flag==true){
            writer.println("登陆成功");
        }else {
            writer.println("登陆失败");
        }

        writer.flush();
        writer.close();
    }

}

package cn.com.xiebiao.tomcat;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.PreparedStatement;

/**
 *
 * Title  : Login.java
 * Company: ZhenBot
 * Author : Vibe Xie  @
 * Time   : Mar 7, 2015 4:25:02 PM
 * Copyright: Copyright (c) 2015
 *
 */
public class Login {
    public static String url="jdbc:mysql://localhost:3306/xiebiaoDB";
    public static String user="xiebiao";
    public static String password="*********";

    public static Connection connection=null;
    public static PreparedStatement preparedStatement=null;
    public static ResultSet resultSet=null;
    public static boolean isConnectServerTrue;
    public static boolean isLoginTrue;

    public static boolean connectServer(){
        try {
            Class.forName("com.mysql.jdbc.Driver");
            connection=DriverManager.getConnection(url, user, password);
            if(connection!=null){
                System.out.println("数据库:"+url+" 连接成功");
                return true;
            }else {
                System.out.println("数据库:"+url+" 连接失败");
                return false;
            }

        } catch (Exception e) {
            // TODO Auto-generated catch block
            System.out.println("jdbc错误");
            e.printStackTrace();
        }
        return false;
    }

    public boolean isUserLogin(String clientName,String clientPassword){
        // TODO Auto-generated method stub
        String sql="select password from ids where name=?;";

        if(connectServer()==false){
            return false;
        }

        try {
            preparedStatement=connection.prepareStatement(sql);
            preparedStatement.setString(1,clientName);
            resultSet=preparedStatement.executeQuery();
            String serverPassword=null;

            if(resultSet.next()==true){
                serverPassword=resultSet.getString("password");
                while(resultSet.next()){
                    serverPassword=resultSet.getString("password");
                }
            }else {
                System.out.println("用户:"+clientName+" 不存在");
                return false;
            }

            System.out.println("数据库中查询的password:"+serverPassword);
            System.out.println("验证中...");

            if(serverPassword.equals(clientPassword)){
                System.out.println(clientName+" 登陆成功");
                isLoginTrue=true;
            }else {
                System.out.println(clientName+" 登陆失败");
                isLoginTrue=false;
            }

        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            try {
                if(resultSet!=null){
                    resultSet.close();
                    resultSet=null;
                }

                if(preparedStatement!=null){
                    preparedStatement.close();
                    preparedStatement=null;
                }

                if(connection!=null){
                    connection.close();
                    connection=null;
                }
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return isLoginTrue;
    }
}