ServletConfig类、Servlet读取初始化参数的几种方式

public class ConfigServletDemo extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//方法一：通过getServletConfig()获得conf对象 --死的
ServletConfig conf = this.getServletConfig();
String name = conf.getInitParameter("name");
String age = conf.getInitParameter("age");
out.print(name+","+age+"<br/>");

//方法二：直接通过当前servlet类的getInitParameter()方法  --死的
String name2 = this.getInitParameter("name");
String age2 = this.getInitParameter("age");
out.print(name2+","+age2+"<br/>");

out.print("<hr/>");
//不知道参数名的情况下，去遍历
//方法三：通过getServletConfig()或当前servlet类的getInitParameterNames()动态获取所有的参数名
ServletConfig conf2 = this.getServletConfig();
Enumeration<String> en = conf.getInitParameterNames();
while(en.hasMoreElements()){
String paramName = en.nextElement(); //key
String value = conf.getInitParameter(paramName);
out.print(paramName+","+value+"<br/>");
}
}
}