Ajax dwr 判断用户是否存在

package com.ajax; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; /** * MySQL数据库连接类 * @author 周尚武 */ public class MySqlConnection { private static final String driver="com.mysql.jdbc.Driver"; private static final String url ="jdbc:mysql://localhost:3306/user"; private static final String name = "root"; private static final String pwd = "accp"; private static Connection con = null; private static PreparedStatement ps = null; private static ResultSet rs = null; /** * 获取数据库连接 * @return */ public static Connection getCon(){ try { Class.forName(driver); con = DriverManager.getConnection(url,name,pwd); } catch (ClassNotFoundException e) { System.out.println("驱动加载错误！"); e.printStackTrace(); } catch (SQLException e) { System.out.println("数据库连接类失败！"); e.printStackTrace(); } return con; } /** * 关闭连接 * @param con */ public static void closeCon(Connection con){ if(con!=null){ try { con.close(); } catch (SQLException e) { e.printStackTrace(); } } } /** * 关闭PreparedStatement对象 * @param ps */ public static void closePre(PreparedStatement ps){ if(ps!=null){ try { ps.close(); } catch (SQLException e) { e.printStackTrace(); } } } /** * 关闭结果对象 * @param rs */ public static void closeReSet(ResultSet rs){ if(rs!=null){ try { rs.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } /** * 释放所有的资源 * @param con * @param ps * @param rs */ public static void closeAll(Connection con,PreparedStatement ps,ResultSet rs){ closeCon(con); closePre(ps); closeReSet(rs); } public static void main(String[] args) { MySqlConnection.getCon(); } }