Women in Technology

Article:		Clustering and Load Balancing in Tomcat 5, Part 2
Subject:		Not able to locate BalancerFilter
Date:		2005-03-03 22:10:40
From:		Falgun
hi there i am not able to locate BalancerFilter.java or BalancerFilter.class. can anyone tell me that how do i forward(redirect) request object, which has userID and password as its parameter to servlet running on some other host. i tried using following code in LoadBalancerServlet getServletContext().getRequestDispatcher("http://172.16.25.54:8080/MyServlets/MainServlet").forward(request, response); but it thorws following exception java.lang.RuntimeException url does not start with '/' please help thanks Falgun thanks in advance Falgun

Showing messages 1 through 2 of 2.

• Not able to locate BalancerFilter
  2005-07-20 02:02:00  IDunno [View]
  
  
  You can see BalancerFilter in Tomcat sources :
  
  
  
  <sourcedir>/jakarta-tomcat-catalina/webapps/balancer/WEB-INF/classes/org/apache/webapp/balancer/BalancerFilter.java
  
  
  Here is the source :
  
  
  
  
/*
* Copyright 2000,2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.webapp.balancer;

import java.io.IOException;
import java.io.InputStream;

import java.net.URL;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


/**
* The balancer filter redirects incoming requests
* based on what rules they match. The rules
* are configurable via an XML document whose URL
* is specified as an init-param to this filter.
*
* @author Yoav Shapira
*/
public class BalancerFilter implements Filter {
/**
* The rules this filter consults.
*/
private RuleChain ruleChain;

/**
* The servlet context.
*/
private ServletContext context;

/**
* Returns the rule chain.
*
* @return The rule chain
*/
protected RuleChain getRuleChain() {
return ruleChain;
}

/**
* Initialize this filter.
*
* @param filterConfig The filter config
* @throws ServletException If an error occurs
*/
public void init(FilterConfig filterConfig) throws ServletException {
context = filterConfig.getServletContext();

String configUrlParam = filterConfig.getInitParameter("configUrl");

if (configUrlParam == null) {
throw new ServletException("configUrl is required.");
}

try {
InputStream input = context.getResourceAsStream(configUrlParam);
RulesParser parser = new RulesParser(input);
ruleChain = parser.getResult();
context.log(
getClass().getName() + ": init(): ruleChain: " + ruleChain);
} catch (Exception e) {
throw new ServletException(e);
}
}

/**
* Filter the incoming request.
* Consults the rule chain to see if
* any rules match this request, and if
* so redirects. Otherwise simply
* let request through.
*
* @param request The request
* @param response The response
* @param chain The filter chain
* @throws IOException If an error occurs
* @throws ServletException If an error occurs
*/
public void doFilter(
ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
if (response.isCommitted()) {
context.log(
getClass().getName()
+ ": doFilter(): not inspecting committed response.");
chain.doFilter(request, response);
} else if (!(request instanceof HttpServletRequest)) {
context.log(
getClass().getName()
+ ": doFilter(): not inspecting non-Http request.");
chain.doFilter(request, response);
} else {
HttpServletRequest hreq = (HttpServletRequest) request;
HttpServletResponse hres = (HttpServletResponse) response;

URL redirectUrl = getRuleChain().evaluate(hreq);

if (redirectUrl != null) {
String encoded =
hres.encodeRedirectURL(redirectUrl.toString());

context.log(
getClass().getName()
+ ": doFilter(): redirecting request for "
+ hreq.getRequestURL().toString() + " to " + encoded);

hres.sendRedirect(encoded);
} else {
chain.doFilter(request, response);
}
}
}

/**
* Destroy this filter.
*/
public void destroy() {
context = null;
ruleChain = null;
}
}


// End of file: BalanceFilter.java

• Not able to locate BalancerFilter
  2005-12-19 20:59:27  minil [View]
  
  
  Hi,
  where to place the BalancerFilter.java file in Web-inf directory. Its urgent. can u plz reply back immediatly.
  
  Thanks in advance.