package com.data;

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




/*
 * 在本项目下新建个文本文件db.properties,内容如下:
 * 
 * drivername=com.mysql.jdbc.Driver
 * url=jdbc:mysql://localhost:3306/databaseName
 * username=root
 * password=root
 **/
public class ConnectDB {

	private static Properties configDB;
	private ConnectDB(){}
	static{
		try {
			configDB = new Properties();
			configDB.load(new FileInputStream("./db.properties"));
		} catch (FileNotFoundException e) {
			e.printStackTrace();
			System.exit(1);
		} catch (IOException e) {
			e.printStackTrace();
			System.exit(1);
		}
		String driverName =configDB.getProperty("drivername");
		try {
 Class.forName(driverName);
 } catch (Exception ex) {
 ex.printStackTrace();
 }
	}
	
	public static Connection getConnection(){
		Connection con = null;
 String strURL = configDB.getProperty("url");
 String strUsername = configDB.getProperty("username");
 String strPwd = configDB.getProperty("password");
 try {
 con = DriverManager.getConnection(strURL, strUsername, strPwd);
 } catch (Exception e) {
 e.printStackTrace();
 }
 return con;
	}
	
 public static void close(ResultSet rs, Statement stmt, Connection con) {
 try {
 if (rs != null)
 rs.close();
 } catch (Exception ex) {
 ex.printStackTrace();
 }
 try {
 if (stmt != null)
 stmt.close();
 } catch (Exception ex) {
 ex.printStackTrace();
 }
 try {
 if (con != null)
 con.close();
 } catch (Exception ex) {
 ex.printStackTrace();
 }
 }
}