新手写的一个DBCP工具类

 package com.xx.questionnaire.util.dao;

 import java.io.IOException;
 import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.Properties;

 import javax.sql.DataSource;

 import org.apache.commons.dbcp2.BasicDataSourceFactory;
 import org.apache.log4j.Logger;

 /**
  * @version 0.1
  * @author Administrator
  *
  */
 public class Dbcp_connection implements JdbcI {
     static Logger log = Logger.getLogger(Dbcp_connection.class);
     private Connection connection;
     /**
      * 在静态块中初始化获得DBCP数据源连接池
      */
     static {
         getDataSource();
         log.info("数据源已在静态块中初始化完成。");
     }

     /**
      *@return 返回Connection连接
      */
     public Connection getConnection() {
         if (connection == null || connection.equals("")) {
             try {
                 setConnection(getDataSource().getConnection());
                 log.info("从数据源中获取连接！");
                 return connection;
             } catch (SQLException e) {
                 log.error("对不起，数据库连接获取失败！");
                 e.printStackTrace();
             }
         }
         return null;
     }
     /**
      * @param sql    SQL语句
      * @return PrepaedStatement对象
      */
     public PreparedStatement getPStatement(String sql) {
         if (sql == null || sql.equals("")) {
             log.error("错误，SQL语句不允许为空!");
             return null;
         }
         PreparedStatement ps = null;
         try {
             ps = getConnection().prepareStatement(sql);
             log.info("SQL语句" + sql + "已经过预编译！");
             return ps;
         } catch (SQLException e) {
             log.error("异常，SQL语句" + sql + "预编译失败！");
             e.printStackTrace();
         }

         return null;
     }

     /**
      * 强制释放Connection连接。
      *
      */
     public void close() {
         try {
             this.connection.close();
             log.info("Connection object" + this.connection.hashCode()
                     + "被强制释放！");
         } catch (SQLException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }

     }

     public void close(Statement ps) {
         // TODO Auto-generated method stub
         try {

             ps.close();
             this.connection.close();
             log.info("Statement（"
                     + ps.hashCode() + "），Connection("
                     + this.connection.hashCode() + ")已被释放！");
         } catch (SQLException e) {
             log.error("异常，JDBC对象关闭失败！");
             e.printStackTrace();
         }

     }
     /**
      * 按照顺序释放JDBC连接。
      */
     public void close(Statement ps, ResultSet rs) {
         // TODO Auto-generated method stub
         try {
             rs.close();
             ps.close();
             this.connection.close();
             log.info("ResultSet（" + rs.hashCode() + "），Statement（"
                     + ps.hashCode() + "），Connection("
                     + this.connection.hashCode() + ")已被释放！");
         } catch (SQLException e) {
             log.error("异常，JDBC对象关闭失败！");
             e.printStackTrace();
         }

     }

     public static void main(String[] args) {
         // TODO Auto-generated method stub
         /* 1 */
         DataSource dds = getDataSource();
         System.out.println(dds == null ? "数据源失败" : "数据源成功");

     }

     /**
      * 全局公用的数据源
      *
      * @return DataSource Object
      */
     private static DataSource getDataSource() {
         String dbcpUrl = "dbcp-mysql.properties";

         DataSource ds;
         Properties p = new Properties();
         try {
             // 通过类的类加载器将属性文件加载至输入流
             p.load(JDBCUtil.class.getClassLoader().getResourceAsStream(dbcpUrl));
             log.info("DBCP配置文件已加载！");

             ds = BasicDataSourceFactory.createDataSource(p);
             log.info("数据源获取成功！");
             return ds;

         } catch (IOException e) {
             log.error("异常，可能是配置文件读取失败。");
             e.printStackTrace();
         } catch (Exception e) {
             e.printStackTrace();
         }

         return null;
     }

     private void setConnection(Connection connection) {
         log.info("获取连接，Hash地址为：" + connection.hashCode());
         this.connection = connection;
     }

     public DataSource getDS() {
         // TODO Auto-generated method stub
         log.info("数据源被外部调用！");
         return getDataSource();
     }

 }