Druid 德鲁伊连接池

public  void druidTest() throws Exception {
        //创建一个Properties 对象 读取配置文件
        Properties properties = new Properties();
        properties.load(new FileInputStream("src\\druid.properties"));
        // 创建一个指定参数的数据库连接池, Druid 连接池
        DataSource dataSource = DruidDataSourceFactory.createDataSource(properties);
        //建立连接
        Connection connection = dataSource.getConnection();
        System.out.println("连接成功");
        connection.close();
    }

配置文件

#key=value
driverClassName=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://localhost:3306/jdbcstudy?rewriteBatchedStatements=true&useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=UTC
username=root
password=root
#initial connection Size
initialSize=10
#min idle connecton size
minIdle=5
#max active connection size
maxActive=20
#max wait time (5000 mil seconds)  最大等待时间(等待队列)
maxWait=5000

Druid工具类

package com.JDBC_Utils;

import com.alibaba.druid.pool.DruidDataSourceFactory;

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

public class JDBCUtilsByDruid {
    /**
     * 基于 druid 数据库连接池的工具类
     */
    private static DataSource ds;

    static {
        try {
            Properties properties = new Properties();
            properties.load(new FileInputStream("src\\druid.properties"));
            ds = DruidDataSourceFactory.createDataSource(properties);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    public static Connection getConnection() {
        try {
            return ds.getConnection();
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }

    public static void close(ResultSet resultSet, Statement statement, Connection connection) {
        try {
            //关闭连接： 在数据库连接池技术中，close 不是真的断掉连接
            //而是把使用的 Connection 对象放回连接池
            if (resultSet != null) {
                resultSet.close();
            }
            if (statement != null) {
                statement.close();
            }
            if (connection != null) {
                connection.close();
            }
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }
}