JDBCUtil

package com.baizhi.JDBCUtil;

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

public class JDBCUtil {
    static ThreadLocal<Connection> tl = new ThreadLocal<Connection>(); 
    private static String className;
    private static String url;
    private static String user;
    private static String pwd;
    static Properties pro = null;
    static {
        //创建properties
        pro = new Properties();
        //获取输入流
        InputStream is = JDBCUtil.class.getResourceAsStream("/JDBCUtil.properties");
        //读取JDBCUtil.properties
        try {
            pro.load(is);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        //获取键值对
         className = pro.getProperty("ClassName");
         url = pro.getProperty("url");
         user = pro.getProperty("user");
         pwd = pro.getProperty("psw");
    }
    //加载驱动.获取连接
    public static Connection getConn() {
        if (tl.get() == null) {
            try {
                Class.forName(className);
                Connection conn = DriverManager.getConnection(url, user,pwd);
                tl.set(conn);
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        } 
        return tl.get();
    }
    
    
    //关闭资源    
    public static void closeAll(Connection conn,PreparedStatement pstm,ResultSet rs) {
        if(rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                throw new RuntimeException(e);
            }
        }
        if(pstm != null) {
            try {
                pstm.close();
            } catch (SQLException e) {
                throw new RuntimeException(e);
            }
        }
        if(conn != null) {
            try {
                tl.remove();
                conn.close();    
            } catch (SQLException e) {
                throw new RuntimeException(e+"关闭conn链接出错");
            }
        }
    }
}

配置文件 （properties）

ClassName = oracle.jdbc.OracleDriver
url = jdbc:oracle:thin:@localhost:1521:xe
user = hr
psw = hr