数据库增删查改方法

package com.util;

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

public class DBUtil {
    //三剑客
    private static Connection con = null;
    private static PreparedStatement ps = null;
    private static ResultSet rs = null;
    //四大金刚
    private static String driver ="com.mysql.jdbc.Driver";
    private static String url="jdbc:mysql://localhost:3306/usystem";
    private static String user="root";
    private static String password="root";
    
    //获得连接
    public static Connection getConnection(){
        try {
            Class.forName(driver);
            con = DriverManager.getConnection(url, user, password);
        } catch (ClassNotFoundException e) {
            System.out.println("加载驱动失败");
            e.printStackTrace();
        } catch (SQLException e) {
            System.out.println("连接数据库失败");
            e.printStackTrace();
        } 
        
        return con;
    }
    
    //关闭连接（查询）
    public static void close(Connection con,PreparedStatement ps,ResultSet rs){
        try {
            rs.close();
            ps.close();
            con.close();
        } catch (SQLException e) {
            System.out.println("关闭失败");
            e.printStackTrace();
        }
    }
    
    
    //关闭连接（增删改）
    public static void close(Connection con,PreparedStatement ps){
        try {
            ps.close();
            con.close();
        } catch (SQLException e) {
            System.out.println("关闭失败");
            e.printStackTrace();
        }
    }    

}