February 27, 2011

Servlet Initialization Parameters & Context Initialization Parameters

In one of the servlets' configuration, configure a Servlet Initialization parameter and retrieve this parameter value in the servlet code. Configure a Context Initialization parameter and retrieve it in any servlet.

package info.icontraining.servlets;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class InitParametersDemoServlet extends HttpServlet {
 
   public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
      PrintWriter out = response.getWriter();
       
      String servletInitParam = getServletConfig().getInitParameter("initParam");
      String contextInitParam = getServletContext().getInitParameter("contextParam");
       
      out.println("<html><body>");
       
      out.println("<p>Servlet Init Parameter Value = ");
      out.println(servletInitParam + "<br/><br/>");
       
      out.println("Context Init Parameter Value = ");
      out.println(contextInitParam + "<br/><br/>");
       
      out.println("</p></body></html>");
      out.close();
   }
}


Configuration for the servlet (along with Servlet Initialization Parameter) and the Context Initialization parameter,

<servlet>
   <servlet-name>initParametersDemoServlet</servlet-name>
   <servlet-class>info.icontraining.servlets.InitParametersDemoServlet</servlet-class>
   <init-param>
      <param-name>initParam</param-name>
      <param-value>initValue</param-value>
   </init-param>
</servlet>
<servlet-mapping>
   <servlet-name>initParametersDemoServlet</servlet-name>
   <url-pattern>/initParameters</url-pattern>
</servlet-mapping>
 
<context-param>
   <param-name>contextParam</param-name>
   <param-value>contextValue</param-value>
</context-param>


URL in browser:

http://localhost:8080/WebAppName/initParameters

No comments:

Post a Comment