Wharf error handling issue

I am facing some problems while installing an error handler in jetty:

I am creating my own error handler:

public class ServerErrorPageErrorHandler extends ErrorPageErrorHandler {
    @Override
    protected void writeErrorPageBody(HttpServletRequest request, Writer writer, int code, String message, boolean showStacks)
            throws IOException {
     String uri= request.getRequestURI();

     writeErrorPageMessage(request,writer,code,message,uri);
     if (showStacks)
        writeErrorPageStacks(request,writer);
        writer.write("<hr><i><small>Powered by OWN-SERVER://</small></i><hr/>\n");
    }
}

      

        
        
        
      

    

And install it in the 'jett-web.xml' file which is located in the '/ webapp / WEB-INF /' folder

<Configure class="org.eclipse.jetty.webapp.WebAppContext">
<Set name="contextPath">/</Set>

<Set name="errorHandler">
    <New class="com.mobile.service.handlers.ServerErrorPageErrorHandler"/>
</Set></Configure>

      

        
        
        
      

    

When Jetty started, it didn't say such a method for the setErrorHandler for the WebAppContext class, (I found the setErrorHandler method in its parent ErrorHandler class, so I think that means)

Then create an error-handler-context.xml file and fill in the file:

<Configure class="org.eclipse.jetty.server.handler.ContextHandler">
  <Set name="contextPath">/</Set>   
  <Set name="errorHandler">
     <New class="com.mobile.service.handlers.ServerErrorPageErrorHandler"/>
   </Set> 
</Configure>

      

        
        
        
      

    

The jetty then starts successfully, but the error handler has no effect.

I just want to change the messages that appear on the "Power by jetty" error pages to "Power by OWN SERVER".

And I don't want to create a new error page.

So how do you implement this?

And I change the config file like this:

<Configure class="org.eclipse.jetty.webapp.WebAppContext">
   <Set name="contextPath">/</Set>
      <Call name="setErrorHandler">
        <Arg>
            <New class="com.hp.mobile.service.handlers.ServerErrorPageErrorHandler"/>
       </Arg>
     </Call>

</Configure>

      

        
        
        
      

    

After launching the pier, it still says NoSuchMethod 'setErrorHanlder' exception,

And I am debugging it and I get an exception:

"java.lang.illegalargumentexception: argument type mismatch" in method.invoke (obj, arg) in "TypeUtil.java"

SetErrorHandler argument is a class ErrorHandler

,

And in my case it comes from ErrorHandler

,

So why is this happening?

By the way: I also change the class ServerErrorPageErrorHandler

to extend from ErrorHandler

, it doesn't work either.