package com.mwq.dao;

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

public class JDBC {

	private static final String DRIVERCLASS = "com.microsoft.jdbc.sqlserver.SQLServerDriver";

	private static final String URL = "jdbc:microsoft:sqlserver://127.0.0.1:1433;DatabaseName=db_DrinkeryManage";

	private static final String USERNAME = "sa";

	private static final String PASSWORD = "";

	private static final ThreadLocal<Connection> threadLocal = new ThreadLocal<Connection>();

	static {// 在靜態代碼塊中加載數據庫驅動
		try {
			Class.forName(DRIVERCLASS).newInstance();// 加載數據庫驅動
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public static Connection getConnection() {// 創建數據庫連接的方法
		Connection conn = threadLocal.get();// 從線程中獲得數據庫連接
		if (conn == null) {// 沒有可用的數據庫連接
			try {
				conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);// 創建新的數據庫連接
				threadLocal.set(conn);// 將數據庫連接保存到線程中
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
		return conn;// 返回數據庫連接
	}

	public static boolean closeConnection() {// 關閉數據庫連接的方法
		boolean isClosed = true;// 默認關閉成功
		Connection conn = threadLocal.get();// 從線程中獲得數據庫連接
		if (conn != null) {// 數據庫連接可用
			threadLocal.set(null);// 清空線程中的數據庫連接
			try {
				conn.close();// 關閉數據庫連接
			} catch (SQLException e) {
				isClosed = false;// 關閉失敗
				e.printStackTrace();
			}
		}
		return isClosed;// 返回關閉結果
	}

}