javaSE JDBC, 连接池, c3p0, DataSource接口，javasec3p0

javaSE JDBC, 连接池, c3p0, DataSource接口，javasec3p0

MySql驱动(jar包)下载：https://pan.baidu.com/s/19BYnGbO3l5MOOic5K4Ooaw  密码：mwoh

c3p0连接池下载(jar包,和xml配置文件)：https://pan.baidu.com/s/18DodkCHFi07MQdTGACQU7Q  密码：m6fq

Demo.java：

package cn.xxx.jdbc.test;
 
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
 
import com.mchange.v2.c3p0.ComboPooledDataSource;
 
public class Demo {
 
	public static void main(String[] args) {
		Connection conn = null;
		PreparedStatement pstmt = null;
		// 1.创建连接池对象
		ComboPooledDataSource dataSource = new ComboPooledDataSource(); // 根据默认配置创建连接池对象
		// ComboPooledDataSource dataSource = new ComboPooledDataSource("配置文件中的配置名"); //根据有名称的配置创建
		try {
			// 2.从连接池中获取连接
			conn = dataSource.getConnection();
			String sql = "insert into tbl_user values(null,?,?)";
			pstmt = conn.prepareStatement(sql);
			pstmt.setString(1, "zhangsan");
			pstmt.setString(2, "123");
			int rows = pstmt.executeUpdate();
			if (rows > 0) {
				System.out.println("添加成功!");
			} else {
				System.out.println("添加失败!");
			}
		} catch (Exception e) {
			throw new RuntimeException(e);
		} finally {  // 释放资源;并不是真正释放,而是将连接归还到连接池中
			if (pstmt != null) {
				try {
					pstmt.close();
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}
			if (conn != null) {
				try {
					conn.close();
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}
		}
	}
}

src/c3p0-config.xml（c3p0连接池的配置文件,放在src目录下）：

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>

	<default-config>  <!-- 默认配置 -->
		<property name="driverClass">com.mysql.jdbc.Driver</property>
		<property name="jdbcUrl">jdbc:mysql:///数据库名</property>
		<property name="user">root</property>
		<property name="password">root</property>
		<property name="initialPoolSize">5</property>
		<property name="maxPoolSize">20</property>
	</default-config>

	<named-config name="配置文件中的配置名">  <!-- 带配置名的配置 -->
		<property name="driverClass">com.mysql.jdbc.Driver</property>
		<property name="jdbcUrl">jdbc:mysql:///数据库名</property>
		<property name="user">root</property>
		<property name="password">root</property>
	</named-config>

</c3p0-config>