Config

1.用途:

    在实际开发中,有些东西不适合在servlet的中写死,就可以通过配置的方法配给servlet

    eg.servlet采用哪个码表; servlet哪个配置文件;

    !!!每个servlet都有自已的config; 而context是属于整个web应用,每个servlet都能访问

2.例子

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		ServletConfig config=getServletConfig();
		//得到指定值
		String value =config.getInitParameter("data");
		System.out.println("data"+"   "+value);
		
		//得到所有值
		Enumeration e=config.getInitParameterNames();
		while(e.hasMoreElements()) {
			String name=(String)e.nextElement();
			String value2=config.getInitParameter(name);
			System.out.println(name+"   "+value2);
		}

	}

配置文件:

<servlet>
  	<servlet-name>11</servlet-name>
  	<init-param>
  		<param-name>data</param-name>
  		<param-value>123</param-value>
  	</init-param>	
  </servlet>