使用properties文件配置数据库

	        public Properties getPropertiesFile(String addr)
	        {
		        try{
			    Properties properties  = new Properties();
			    FileInputStream file = new FileInputStream(addr);
			    properties.load(file);
			    return properties;
		            }catch(IOException e){
			    e.printStackTrace();
			    return null;
		           }
	        }
		
           Properties properties = getPropertiesFile("/connection.properties");
		String driver = properties.getProperty("DRIVER");
		String url = properties.getProperty("URL");
		String user = properties.getProperty("USER");
		String pwd = properties.getProperty("PASSWD");
		try{
			Class.forName(driver);
		}catch(ClassNotFoundException e){
			e.printStackTrace();
		}
		try{
			this.connection = DriverManager.getConnection(url,user,pwd);
		}catch(SQLException e){
			e.printStackTrace();
		}