package com.mwq.dao;

import java.sql.*;

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 {// 通過靜態(tài)方法加載數(shù)據(jù)庫驅(qū)動
		try {
			Class.forName(DRIVERCLASS).newInstance();// 加載數(shù)據(jù)庫驅(qū)動
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

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

	public static boolean closeConnection() {// 關(guān)閉數(shù)據(jù)庫連接的方法
		boolean isClosed = true;
		Connection conn = threadLocal.get();// 從線程中獲得數(shù)據(jù)庫連接
		threadLocal.set(null);// 清空線程中的數(shù)據(jù)庫連接
		if (conn != null) {// 數(shù)據(jù)庫連接可用
			try {
				conn.close();// 關(guān)閉數(shù)據(jù)庫連接
			} catch (SQLException e) {
				isClosed = false;
				e.printStackTrace();
			}
		}
		return isClosed;
	}

}