java 实现jdbc连接mysql

package util;

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

import javax.sql.DataSource;

import org.apache.commons.dbcp.BasicDataSourceFactory;

public class JdbcUtil5 {
	private static Properties map = new Properties();
	private static DataSource ds=null;
	static{
		InputStream is = null;
		try {
			is =JdbcUtil4.class.getResourceAsStream("/util/conn.properties");
			map.load(is);
			ds=BasicDataSourceFactory.createDataSource(map);
		} catch (Exception e) {
			e.printStackTrace();
		} finally{
			if(is!=null)try {is.close();} catch (IOException e) {e.printStackTrace();}
		}
	}
	
	public static ThreadLocal tol = new ThreadLocal();
	
	public static Connection getConnection(){
		try {
			Connection conn =tol.get();
			if(conn==null){
				conn=ds.getConnection();
				tol.set(conn);
			}
			return conn;
		} catch (Exception e) {
			e.printStackTrace();
			throw new RuntimeException();
		}
		
	}
	public static void close(ResultSet rs,Statement stm,Connection conn){
		if(rs!=null)try {rs.close();} catch (Exception e) {e.printStackTrace();}
		if(stm!=null)try {stm.close();} catch (Exception e) {e.printStackTrace();}
		if(conn!=null)try {conn.close();} catch (Exception e) {e.printStackTrace();}
	}
}