getServletContext和getServletConfig的getInitParameter方法区别

<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.4" ... <context-param> <param-name>P1 </param-name> <param-value>This Is web-app Value </param-value> </context-param> ... <servlet> <servlet-name>HelloServlet </servlet-name> <servlet-class>suman.Servlet.HelloServlet </servlet-class> <init-param> <param-name>P1 </param-name> <param-value>This is the servlet value </param-value> </init-param> </servlet> ... </web-app> ============================== public class HelloServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ... String s1 = getServletConfig().getInitParameter("P1"); String s2 = getServletContext().getInitParameter("P1"); String s3 = getServletConfig().getServletContext().getInitParameter("P1"); String s4 = getInitParameter("P1"); out.println("SumanChina_DoGet"); out.println(" <br>"); out.println("s1:"+s1+" <br>"); out.println("s2:"+s2+" <br>"); out.println("s3:"+s3+" <br>"); out.println("s4:"+s4); ... } }输出结果：             s1:This is the servlet value           s2:This Is web-app Value            s3:This Is web-app Value             s4:This is the servlet value分析：          1：getServletContext()取得的是 <context-param>配置的参数                getServletConfig()取得的是 <servlet> <init-param>配置的参数           2： getServletContext()应用于整个web App,而getServletConfig()仅应用于当前Servlet。 但是ServletConfig对象拥有ServletContext的引用。所以可以通过getServletConfig()来获得web App的 初始值。

转自：http://baiduqing.blog.163.com/blog/static/1896291012011611105621698/