Problem in simple Filter servlet Program

[Parthiban Malayandi]

Hi all ,
I'm new to Servlets .I just studied filtering in Servlets and tried a small program .

Here is the coding

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
 
public class FilterLifeCycle  implements Filter {
public void init(FilterConfig config) 
throws ServletException {
System.out.println("Filter initialized");
}

public void doFilter(ServletRequest req,ServletResponse resp,FilterChain chain)
throws ServletException,IOException {
System.out.println("**doFilter method invoked*");
chain.doFilter(req,resp);
PrintWriter out = resp.getWriter();
out.println("End of Response");
}


public void destroy(){
System.out.println("Filter is been destroyed");
}
}

Here is the part of web.xml content for this filter

  
  <filter>
<filter-name>BasicFilter</filter-name>
<filter-class>FilterLifeCycle</filter-class>
</filter>


<filter-mapping>
<filter-name>BasicFilter</filter-name>
<servlet-name>FilterDemo</servlet-name>
</filter-mapping>
     
        <servlet>
<servlet-name>FilterDemo</servlet-name>
<servlet-class>FilterDemoServlet</servlet-class>
</servlet>
 

The problem is Filtering is not working .
I find that doFilter method is not invoked at all when I request "FilterDemo" servlet (which is suppose to be invoked ).
Please tell me what is the problem in that coding .

Thanks in advance

[Bear Bibeault]

Why are your classes not in packages? That's the first thing to take care of in order to eliminate that as a possible source of error.

[Seetharaman Venkatasamy]

yes,as beer mentioned above

-------------------------------
<filter-class>FilterLifeCycle</filter-class>
-------------------------------

this should be fully qualified class name.

[Parthiban Malayandi]

Hi thanks for your replies .
I tried after put it in to package but still (as previous) filter's init() and destroy() methods alone invoked .
Is anything I'm missing in filter mapping ?
I'm using tomcat 5.5.x series

[Amit Ghorpade]

Originally posted by seetharaman venkatasamy:
yes,as beer mentioned above

The name is Bear, serious typo I must say

[Amit Ghorpade]

I tried after put it in to package but still (as previous) filter's init() and destroy() methods alone invoked .

Why do you think that the doFilter() was not called? What is your output in the browser?
Wasn't the servlet (or the next filter in the chain) invoked?

[Parthiban Malayandi]

Hi all,

After struggling for a day I found out the problem .

The problem is due to "Invoker" Servlet.While practicing small programs normally I take advance of using "Invoker" servlet without explicitly providing servlet mapping for each servlet in web.xml that is the problem.

If I do so doFilter method is not invoked where as the requested servlet works perfectly but if I explicitly provide url-pattern for that servlet(or url-pattern for that filter) doFilter method of that Filter is invoked

Thanks to all for your replies

[Bear Bibeault]

Lesson learned: take no shortcuts even for smaller programs.

But yeah, if you map the filter to a servlet mapping, and then don't use that mapping, no filter will be invoked.