连接池之DBCP

DBCP连接池是Apache 提供的性能也不错
准备:
1):拷贝jar:commons-dbcp-1.4.jar ,    commons-pool-1.5.6.jar
2):build path,添加到classpath路径.
3):阅读文档:commons-dbcp-1.3-src\doc\BasicDataSourceExample.java
dbcp.properties:
编写该文件:
key名必须等于BasicDataSource中的属性名(由setter方法决定).
----------------------------------------------------------------------
driverClassName=com.mysql.jdbc.Driver
url=jdbc:mysql:///jdbcdemo
username=root
password=admin
maxActive=10
----------------------------------------------------------------------
----------------------工具类代码

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

import javax.sql.DataSource;

import org.apache.commons.dbcp.BasicDataSourceFactory;
/***
* DBCP 连接池工具类
* @author mldn
*
*/
public class MyDbcpUity {
   //配置文件
   private static Properties prod=new Properties();
   //连接池对象
   private static DataSource dataSource=null;
   static {
       //读取配置文件路径
       InputStream input=Thread.currentThread().getContextClassLoader().getResourceAsStream("dbcp.properties");

       try {
           //加载文件路径进内存
           prod.load(input);
           //通过BasicDataSourceFactory工厂模式进行创建连接池对象
           dataSource=BasicDataSourceFactory.createDataSource(prod);
       } catch (Exception e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       }
   }
   //返回一个数据库的连接对象
    public static Connection getConn(){
       try {
           //从连接池当中获取一个连接
           return dataSource.getConnection();
       } catch (SQLException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       }
       return null;
    }
}
}
------------------------------------------测试代码
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import org.junit.Test;

import cn.heima.jdbc.DatabaseConnection;

public class MyDbcpTest2 {
   @Test
   public void finayAll() {
       //写一条sql语句
       String sql = "select * from exam";
       //三大执行官
       Connection conn = null;
       PreparedStatement prep = null;
       ResultSet result = null;
       try {
           //预执行
           conn = MyDbcpUity.getConn();
           prep=conn.prepareStatement(sql);
           result=prep.executeQuery();
           while(result.next()){
               System.out.println(result.getString("name")+" "+result.getDouble("english")+" "+result.getDouble("chinese")+" "+result.getString("math"));
           }
       } catch (SQLException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       }
       //释放资源
       finally{
           DatabaseConnection.Close(result, conn,prep);
       }
   }

}

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