jAVA---数据库连接池

package java4.connection;

import java.beans.PropertyVetoException;
import java.sql.Connection;
import java.sql.SQLException;

import org.junit.Test;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class C3P0Test {
	//方式一：
	@Test
	public void testGetConnection() throws Exception{
		//获取C3p0数据库连接池
		ComboPooledDataSource cpds = new ComboPooledDataSource();
		cpds.setDriverClass("com.mysql.cj.jdbc.Driver");
		cpds.setJdbcUrl("jdbc:mysql://localhost:3306/test");
		cpds.setUser("root");
		cpds.setPassword("abc123");
		
		//通过设置相关的参数，对数据库连接池进行管理
		//设置初始时数据库连接池中的连接数
		cpds.setInitialPoolSize(10);
		Connection conn = cpds.getConnection();
		System.out.println(conn);
		
	}
	
	//方式二：使用配置文件
	@Test
	public void testGetConnection1() throws Exception{
		ComboPooledDataSource cpds = new ComboPooledDataSource("helloc3p0");
		Connection conn = cpds.getConnection();
		System.out.println(conn);
		
	}
}

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
	<named-config name="helloc3p0">
		<!-- 提供获取连接的4个基本信息 -->
		<property name="driverClass">com.mysql.cj.jdbc.Driver</property>
		<property name="jdbcUrl">jdbc:mysql:///test</property>
		<property name="user">root</property>
		<property name="password">abc123</property>
		
		<!-- 进行数据库连接池管理的基本信息 -->
		<!-- 当数据库连接池中的连接数不够时，c3p0一次性向数据库服务器申请的连接数 -->
		<property name="acquireIncrement">5</property>
		<!-- c3p0数据库连接池中初始化时的连接数 -->
		<property name="initialPoolSize">10</property>
		<!-- c3p0数据库连接池维护的最少连接数 -->
		<property name="minPoolSize">10</property>
		<!-- c3p0数据库连接池维护的最多的连接数 -->
		<property name="maxPoolSize"></property>
		<!-- c3p0数据库连接池最多维护的Statement的个数 -->
		<property name="maxStatements">50</property>
		<!-- 每个连接中最多可以使用的Statement的个数 -->
		<property name="maxStatementPerConnection">2</property>
	</named-config>
</c3p0-config>

---

package java4.connection;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.util.Properties;

import javax.sql.DataSource;

import org.apache.commons.dbcp.BasicDataSourceFactory;
import org.junit.Test;

/*
 * 	测试DBCP的数据库连接池技术
 */
public class DBCPTest {
	//使用配置文件
	@Test
	public void testGetConnection1() throws Exception{
		Properties pros = new Properties();
		
		InputStream is = ClassLoader.getSystemClassLoader().getResourceAsStream("dbcp.properties");
		pros.load(is);
		DataSource source = BasicDataSourceFactory.createDataSource(pros);
		Connection conn = source.getConnection();
		System.out.println(conn);
		
	}
}

driverClassName=com.mysql.cj.jdbc.Driver
url=jdbc:mysql:///test
username=root
password=abc123

initialSize=10

---

package java4.connection;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.util.Properties;

import javax.sql.DataSource;

import org.junit.Test;

import com.alibaba.druid.pool.DruidDataSourceFactory;

/*
 * 	Druid数据库连接池
 */
public class DruidTest {
	@Test
	public void getConnection() throws Exception{
		Properties pros = new Properties();
		InputStream is = ClassLoader.getSystemClassLoader().getResourceAsStream("druid.properties");
		
		pros.load(is);
		DataSource source = DruidDataSourceFactory.createDataSource(pros);
		Connection conn = source.getConnection();
		System.out.println(conn);
		
		
	}
}

url=jdbc:mysql:///test
username=root
password=abc123
driverClassName=com.mysql.cj.jdbc.Driver

initialSize=10
maxActive=10