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();
    }

}