[转]DBCP连接池的最简单应用(用于ORACLE数据库)

http://blog.csdn.net/iihero/article/details/8254107

 http://www.programgo.com/article/81693457907/

鉴于有人问起DBCP直接用于JDBC连接的问题，我做了一个最简单的示例。所有资源来源于网上。它不需要什么Web容器，就是一简单的控制台应用。

资源：
http://apache.etoak.com//commons/pool/binaries/commons-pool-1.5.6-bin.zip
http://labs.renren.com/apache-mirror//commons/dbcp/binaries/commons-dbcp-1.4-bin.zip
http://download.java.net/maven/1/javaee/jars/javaee-api-5.jar
当然，还有oracle jdbc要用的ojdbc14.jar (适用于oracle9i及以上版本)

工程文件：放到这里了。http://dl.iteye.com/topics/download/210279f0-f752-37a6-969f-d58ba13cc394

数据库连接信息：
jdbc:oracle:thin:scott/tiger@sean-m700:1521:ora92
sean-m700是主机名，ora92是oracle数据库的instance ID. 我手头的机器上没有安装oracle数据库，用的是很早以前的一个oracle9.2的拷贝，重新安装实例和相应服务得来的。 

源码如下：借化献佛，源码也是从网上得来的。(http://svn.apache.org/viewvc/commons/proper/dbcp/trunk/doc/BasicDataSourceExample.Java?revision=1100136&view=markup)

/*
//
33  // Here's a simple example of how to use the BasicDataSource.
34  //
35
36  //
37  // Note that this example is very similiar to the PoolingDriver
38  // example.
39
40  //
41  // To compile this example, you'll want:
42  //  * commons-pool-1.5.6.jar
43  //  * commons-dbcp-1.3.jar (JDK 1.4-1.5) or commons-dbcp-1.4 (JDK 1.6+)
44  //  * j2ee.jar (for the javax.sql classes)
45  // in your classpath.
46  //
47  // To run this example, you'll want:
48  //  * commons-pool-1.5.6.jar
49  //  * commons-dbcp-1.3.jar (JDK 1.4-1.5) or commons-dbcp-1.4 (JDK 1.6+)
50  //  * j2ee.jar (for the javax.sql classes)
51  //  * the classes for your (underlying) JDBC driver
52  // in your classpath.
53  //
54  // Invoke the class using two arguments:
55  //  * the connect string for your underlying JDBC driver
56  //  * the query you'd like to execute
57  // You'll also want to ensure your underlying JDBC driver
58  // is registered.  You can use the "jdbc.drivers"
59  // property to do this.
60  //
61  // For example:
62  //  java -Djdbc.drivers=oracle.jdbc.driver.OracleDriver
63  //       -classpath commons-pool-1.5.6.jar:commons-dbcp-1.4.jar:j2ee.jar:oracle-jdbc.jar:.
64  //       PoolingDataSourceExample
65  //       "jdbc:oracle:thin:scott/tiger@myhost:1521:mysid"
66  //       "SELECT * FROM DUAL"
*/
/*
The Oracle connection URL for the thin client-side driver ojdbc14.jar has the following format:
jdbc:oracle:thin:[user/password]@[host][:port]:SID
jdbc:oracle:thin:[user/password]@//[host][:port]/SID

  user - The login user name defined in the Oracle server.

  password - The password for the login user.

  host - The host name where Oracle server is running.
         Default is 127.0.0.1 - the IP address of localhost.

  port - The port number where Oracle is listening for connection.
         Default is 1521.

  SID  - System ID of the Oracle server database instance.
         SID is a required value. By default, Oracle Database 10g Express
         Edition creates one database instance called XE.
*/

import org.apache.commons.dbcp.BasicDataSource;
import javax.sql.*;
import java.sql.*;

public class TestDataSource
{

    /**
     * @param args
     */
    public static void main(String[] args)
    {
        System.out.println("Setting up data source.");
        String url = "jdbc:oracle:thin:scott/tiger@sean-m700:1521:ora92";
        DataSource dataSource = setupDataSource(url);
        System.out.println("Done...");

        // Now, we can use JDBC DataSource as we normally would.
        //
        Connection conn = null;
        Statement stmt = null;
        ResultSet rset = null;

        try {
            System.out.println("Creating connection.");
            conn = dataSource.getConnection();
            System.out.println("Creating statement.");
            stmt = conn.createStatement();
            System.out.println("Executing statement.");
            rset = stmt.executeQuery("select 1 from DUAL");
            System.out.println("Results:");
            int numcols = rset.getMetaData().getColumnCount();
            while(rset.next()) {
                for(int i=1;i<=numcols;i++) {
                    System.out.print("	" + rset.getString(i));
                }
                System.out.println("");
            }
        } catch(SQLException e) {
            e.printStackTrace();
        } finally {
            try { if (rset != null) rset.close(); } catch(Exception e) { }
            try { if (stmt != null) stmt.close(); } catch(Exception e) { }
            try { if (conn != null) conn.close(); } catch(Exception e) { }
        }
    }

    public static DataSource setupDataSource(String connectURI) {
        BasicDataSource ds = new BasicDataSource();
        ds.setDriverClassName("oracle.jdbc.driver.OracleDriver");
        ds.setUsername("scott");
        ds.setPassword("tiger");
        ds.setUrl(connectURI);
        return ds;
    }

    public static void printDataSourceStats(DataSource ds) {
        BasicDataSource bds = (BasicDataSource) ds;
        System.out.println("NumActive: " + bds.getNumActive());
        System.out.println("NumIdle: " + bds.getNumIdle());
    }

    public static void shutdownDataSource(DataSource ds) throws SQLException {
        BasicDataSource bds = (BasicDataSource) ds;
        bds.close();
    }

}

不过，需要说明的是，DBCP连接池是几个开源连接池里最不适合用于生产环境的，经常会出现死连接现象。 而cp30和proxool都是不错的选择。DBCP用于测评开发环境，还是比较便利的。