java sql包下的Connection類裡的setAutoCommit方法

在程式中可能一個業務包含兩個或兩個以上的sql操作，這是就需要把兩個sql封裝成一個事務提交，

setAutoCommit預設是ture的狀態，表示每個sql自動提交。

所以我們根據專案情況一般吧它設為false，然後再後邊手動紙箱commit或rollback。

DB資料庫封裝類：

package com.project.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

import org.apache.log4j.Logger;

public class DB{
	private static Logger logger=Logger.getLogger(DB.class.getName());
	
	protected String _driver;
	protected String _url;
	protected String _user;
	protected String _passwd;
	protected String _host;
	protected String _port;
	
	protected Connection _conn;
	protected boolean _Connected = false;
	protected boolean _autoCommit=true;//default:true

	public DB(String driver, String url, String user, String passwd){
		_driver = driver;
		_url=url;
	    _user = user;
	    _passwd = passwd;
	}
	
	public void connect() throws Exception {
	    try {
	    	logger.debug("begin connect db");
			Class.forName(_driver);
		    _conn = DriverManager.getConnection(_url, _user, _passwd);		
			_Connected = true;
			logger.debug("db connected");
			_conn.setAutoCommit(_autoCommit);
	      } catch (Exception e) {
	    	  logger.error("db error" + e.getMessage());
	      }
	}
	
	public Connection get_conn() throws Exception{
		if (!_Connected)
			try {
				connect();
			} catch (Exception e) {
				throw e;
			}
		return _conn;
	}
	
	public void commit(){
		try{
		if(!_conn.getAutoCommit())
			_conn.commit();
		}catch(Exception e){
			logger.error(e);
		}
	}
	
	public void close() throws Exception {
		try {
			_conn.close();
			_Connected = false;
			logger.debug("db closed");	
		} catch (SQLException e) {
			logger.error(e.getMessage());
			throw new Exception(e);
		}
	}
	
	public void set_autoCommit(boolean autoCommit){
		this._autoCommit=autoCommit;
	}
	
	public void set_connectClosed(){
		_Connected=false;
	}
	 
	public String get_url() {
		return _url;
	}

}