c3p0连接池]

<c3p0-config>
    <!-- 默认配置 -->
  <default-config>
    <property name="jdbcUrl">jdbc:mysql://localhost:3306/day19</property>
    <property name="user">root</property>
    <property name="password">root</property>
    <property name="driverClass">com.mysql.jdbc.Driver</property>
    
    <property name="initialPoolSize">5</property>
    <property name="maxPoolSize">8</property>
    <property name="checkoutTimeout">5000</property>
  </default-config>

   <!-- 命名配置 -->
  <named-config name="oracle">
     <property name="jdbcUrl">jdbc:oracle:thin:@localhost:1521:orcl</property>
     <property name="user">eric</property>
     <property name="password">123456</property>
     <property name="driverClass">oracle.jdbc.driver.OracleDriver</property>
    
     <property name="initialPoolSize">5</property>
     <property name="maxPoolSize">8</property>
    <property name="checkoutTimeout">5000</property>
   </named-config>


</c3p0-config>

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

import org.junit.Test;

import com.mchange.v2.c3p0.ComboPooledDataSource;

/**
 * jdbc使用c3p0连接池
 * @author APPle
 *
 */
public class TestC3P0 {
    
    private static String url = "jdbc:mysql://localhost:3306/day19";
    private static String user = "root";
    private static String password = "root";
    private static String driverClass = "com.mysql.jdbc.Driver";
    
    @Test
    public void test1(){
        try {
            //1.创建连接池对象
            ComboPooledDataSource pool = new ComboPooledDataSource();
            
            //2.设置连接参数
            pool.setJdbcUrl(url);
            pool.setUser(user);
            pool.setDriverClass(driverClass);
            pool.setPassword(password);
            
            //3.设置连接池参数
            pool.setInitialPoolSize(5);//初始化连接数
            pool.setMaxPoolSize(8);//最大连接数
            pool.setCheckoutTimeout(5000);//最大等待时间
            
            //4.获取连接
            for(int i=1;i<=9;i++){
                Connection conn = pool.getConnection(); //遵守sun公司的jdbc的DataSource接口规范:所有连接池对象必须实现的接口
                System.out.println(conn);
                
                if(i==3){
                    //返回池中
                    conn.close();
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    /**
     * 使用配置文件设置连接参数和连接池参数
     * 默认规则：c3p0启动时会到当前项目的类路径下，读取一个叫c3p0-config.xml文件。
     */
    @Test
    public void test2(){
        try {
            //1.创建连接池对象
            //连接一个数据库只能创建一个连接池对象
            //ComboPooledDataSource pool = new ComboPooledDataSource();//对应的是使用default-config的参数去创建连接池
            ComboPooledDataSource pool = new ComboPooledDataSource("oracle");//对应的使用名称为oracle的name-config的参数去创建连接池
            
            //2.获取连接
            for(int i=1;i<=9;i++){
                Connection conn = pool.getConnection(); //遵守sun公司的jdbc的DataSource接口规范:所有连接池对象必须实现的接口
                System.out.println(conn);
                
                if(i==3){
                    //返回池中
                    conn.close();
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}