JDBCUtils类_druid数据库连接池

创建数据库mydb

新建查询

CREATE TABLE `t_user`  (
  `uid` int(8) NOT NULL AUTO_INCREMENT,
  `username` varchar(255)  NOT NULL,
  `password` varchar(255)  NOT NULL,
  `email` varchar(255) NULL DEFAULT NULL,
  PRIMARY KEY (`uid`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 2  ROW_FORMAT = Dynamic;

写好配置文件 druid.properties

driverClassName=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost\:3306/mydb?useUnicode\=true&characterEncoding\=utf-8
username=root
password=123456
initialSize=5
maxActive=10
maxWait=3000

导入jar包 ：

•                 druid-1.0.9.jar  
•                 mysql-connector-java-5.1.37-bin.jar

链接：https://pan.baidu.com/s/13yhG_qBIu0pi_4GXK5o9Zg 
提取码：v38y 

 

写工具类JDBCUtils   JDBCUtils.java

package com.util;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

import javax.sql.DataSource;

import com.alibaba.druid.pool.DruidDataSourceFactory;

public class JDBCUtils {
	// 1.声明静态数据源成员变量
	private static DataSource ds;

	// 2.创建连接池对象
	static {
		// 加载配置文件中的数据
		InputStream is = JDBCUtils.class.getClassLoader().getResourceAsStream("druid.properties");
		Properties pp = new Properties();

		try {
			pp.load(is);
			// 创建连接池，使用配置文件中的参数
			ds = DruidDataSourceFactory.createDataSource(pp);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	// 3.定义公有的得到数据源的方法
	public static DataSource getDataSource() {
		return ds;
	}

	// 4.定义得到连接对象的方法
	public static Connection gerConnection() throws SQLException {
		return ds.getConnection();
	}

	// 5.定义关闭资源的方法
	public static void close(Connection conn, Statement stmt, ResultSet rs) {
		if (rs != null) {
			try {
				rs.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}

		if (stmt != null) {
			try {
				stmt.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}

		if (conn != null) {
			try {
				conn.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}

	// 6.重载关闭方法
	public static void close(Connection conn, Statement stmt) {
		close(conn, stmt, null);
	}
	
	
	//测试 插入操作
	public static void main(String[] args) {
		Connection conn = null;
		PreparedStatement pstmt = null;
		// 1.获取连接
		try {
			conn = JDBCUtils.gerConnection();
			//2.定义sql
			String sql = "insert into t_user values(null,?,?,?)";
			//3.获取pstmt对象
			pstmt = conn.prepareStatement(sql);
			//4.给？赋值
			pstmt.setString(1, "张三");
			pstmt.setString(2, "123456");
			pstmt.setString(3, "[email protected]");
			//5.执行sql
			int count = pstmt.executeUpdate();
			System.out.println(count);
					
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			//6.释放资源
			JDBCUtils.close(conn, pstmt);
		}
		

	}
}