day18 17.c3p0连接池使用

连接池时间长不用空闲着,dbcp是不回收的，性能可能有些问题。c3p0是可以自动回收。实际开发中c3p的生产力比dbcp强，性能上更强。

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package cn.itcast.datasource;
 
import java.beans.PropertyVetoException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
 
import org.junit.Test;
 
import com.mchange.v2.c3p0.ComboPooledDataSource;
 
public class C3p0Test {
 
    //手动
    @Test
    public void test1() throws PropertyVetoException, SQLException{
        ComboPooledDataSource cpds = new ComboPooledDataSource();
        cpds.setDriverClass("com.mysql.jdbc.driver");
        cpds.setJdbcUrl("jdbc:mysql:///day18");
        cpds.setUser("root");
        cpds.setPassword("");
        //得到一个Connection
        Connection con = cpds.getConnection();
        ResultSet rs= con.createStatement().executeQuery("select * from account");
        while(rs.next()){
            System.out.println(rs.getInt("id")+"   "+rs.getString("name"));
        }
 
    rs.close();
    con.close();//将Connection对象重新装入到连接池.
    }
 
    @Test
    public void test2() throws SQLException{
        ComboPooledDataSource cpds = new ComboPooledDataSource();
 
        //得到一个Connection
        Connection con = cpds.getConnection();
        ResultSet rs= con.createStatement().executeQuery("select * from account");
        while(rs.next()){
            System.out.println(rs.getInt("id")+"   "+rs.getString("name"));
        }
 
    rs.close();
    con.close();//将Connection对象重新装入到连接池.
 
    String path= this.getClass().getResource("/").getPath();
    System.out.println(path);//你在搜索时肯定能找到这个路径嘛 c3p0的底层直接找classpath路径 然后去找指定名称文件  名称是固定的
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
  <default-config>
    <property name="driverClass">com.mysql.jdbc.Driver</property>
    <property name="jdbcUrl">jdbc:mysql:///day18</property>
    <property name="user">root</property>
    <property name="password"></property>
 
  </default-config>
 
</c3p0-config>