DBCP连接池的最简单应用(用于ORACLE数据库)
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("\t" + 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。