JDBC工具类（druid）

package cn.itcast.util;

import com.alibaba.druid.pool.DruidDataSourceFactory;

import javax.sql.DataSource;
import java.io.FileInputStream;
import java.io.IOException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

/**
 * public static DataSource getDataSource()
 public static Connection getConnection()
 public static void close(Connection conn, Statement stmt, ResultSet rs)

 */

public class JdbcUtils{
    //获取连接池数据源

    public static DataSource getDataSource() throws IOException {
        Properties properties = new Properties();
         //使用相对路径加载配置文件，相对路径的获取方法写在下面的注释里
        properties.load(new FileInputStream("spring_day02\\src\\main\\resources\\druid.properties"));
        DataSource dataSource = null;
        try {
            //利用属性创建数据源对象
            dataSource = DruidDataSourceFactory.createDataSource(properties);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return dataSource;
    }
    //获取连接对象
    public static Connection getConnection(){
        Connection conn = null ;
        try {
            conn = getDataSource().getConnection();
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return conn;
    }

    //关闭资源
    public static void close(Connection conn, Statement stmt, ResultSet rs){
        try {
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }try {
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }try {
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
//    //测试连接是否正确
//    public static void main(String[] args) throws IOException {
//      System.out.println("当前相对路径===="+System.getProperty("user.dir"));
//        System.out.println(JdbcUtils.getConnection());
//    }

    /**
     * druid.proterties
     *       #数据库连接参数
             url=jdbc:mysql:///spring01
             username=root
             password=123
             driverClassName=com.mysql.jdbc.Driver
             #连接池连接参数
             initialSize=3
             maxActive=10
             maxWait=2000
     * pom依赖：
     * 
     org.springframework
     spring-context
     

     
     org.springframework
     spring-jdbc
     
     
     mysql
     mysql-connector-java
     

     
     
     com.alibaba
     druid
     
     *
     *
     *
     */
}