JdbcUtil的封装（获取connection对象）

package com.liujinghe.util;

import java.io.FileInputStream;
import java.io.IOException;
import java.sql.*;
import java.util.Properties;

public class JdbcUtil6 {
    /**
     * 加载驱动
     * 设置url，user，password
     * 获取数据库链接对象
     * 关闭资源
     */
    private static String url=null;
    private static String user=null;
    private static String password=null;
    private static String driver=null;
    static{
        //创建properties对象
        Properties properties = new Properties();
        //将db.properties文件读入到properties对象中
        try {
            properties.load(new FileInputStream("./src/db.properties"));
            //获取值
            url=properties.getProperty("url");
            user=properties.getProperty("user");
            password=properties.getProperty("password");
            driver=properties.getProperty("driver");
            //加载驱动
            Class.forName(driver);
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
    //获取数据库链接对象
    public static Connection getConnection(){
        Connection connection = null;
        try {
            connection = DriverManager.getConnection(url, user, password);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return connection;
    }
    //关闭资源
    public static void close(Connection connection,Statement statement){
        close(connection,statement,null);
    }
    public static void close(Connection connection, Statement statement, ResultSet resultSet){
        if(connection!=null){
            try {
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(statement!=null){
            try {
                statement.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(resultSet!=null){
            try {
                resultSet.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}