学步园

package com.crazy4j.utils;

import java.io.InputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;

import javax.sql.DataSource;

import org.apache.commons.dbcp.BasicDataSourceFactory;

public class JdbcUtils_DBCP {
	private static ThreadLocal<Connection> tl=new ThreadLocal<Connection>();
	private static DataSource ds = null;
	static{
		try{
			InputStream in = JdbcUtils_DBCP.class.getClassLoader().getResourceAsStream("dbcpconfig.properties");
			Properties prop = new Properties();
			prop.load(in);
			
			BasicDataSourceFactory factory = new BasicDataSourceFactory();
			ds = factory.createDataSource(prop);
		}catch (Exception e) {
			throw new ExceptionInInitializerError(e);
		}
	}
	public static DataSource getDataSource() throws SQLException{
		return ds;
	}
	public static Connection getConnection() throws SQLException{
		try{
			//得到当前线程上绑定的连接
			Connection conn = tl.get();
			if(conn==null){  //代表线程上没有绑定连接
				conn = ds.getConnection();
				tl.set(conn);
			}
			return conn;
		}catch (Exception e) {
			throw new RuntimeException(e);
		}
	}
	
	
	public static void startTransaction(){
		try{
			//得到当前线程上绑定连接开启事务
			Connection conn = tl.get();
			if(conn==null){  //代表线程上没有绑定连接
				conn = ds.getConnection();
				tl.set(conn);
			}
			conn.setAutoCommit(false);
		}catch (Exception e) {
			throw new RuntimeException(e);
		}
	}
	
	
	public static void commitTransaction(){
		try{
			Connection conn = tl.get();
			if(conn!=null){
				conn.commit();
			}
		}catch (Exception e) {
			throw new RuntimeException(e);
		}
	}
	
	public static void closeConnection(){
		try{
			Connection conn = tl.get();
			if(conn!=null){
				conn.close();
			}
		}catch (Exception e) {
			throw new RuntimeException(e);
		}finally{
			tl.remove();   //千万注意，解除当前线程上绑定的链接（从threadlocal容器中移除对应当前线程的链接）
		}
	}
}