/*
* Copyright (C) 2012 Red Hat, Inc. and/or its affiliates.
*
* 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.jboss.errai.bus.server.servlet;
import static org.slf4j.LoggerFactory.getLogger;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.slf4j.Logger;
import java.io.IOException;
/**
* The default DefaultBlockingServlet which provides the HTTP-protocol gateway
* between the server bus and the client buses.
* <p/>
* <h2>Configuration</h2>
* <p/>
* The DefaultBlockingServlet, as its name suggests, is normally configured as
* an HTTP Servlet in the <code>web.xml</code> file:
* <p/>
* <pre>
* {@code <servlet>}
* {@code <servlet-name>ErraiServlet</servlet-name>}
* {@code <servlet-class>org.jboss.errai.bus.server.servlet.DefaultBlockingServlet</servlet-class>}
* {@code <load-on-startup>1</load-on-startup>}
* {@code </servlet>}
*
* {@code <servlet-mapping>}
* {@code <servlet-name>ErraiServlet</servlet-name>}
* {@code <url-pattern>*.erraiBus</url-pattern>}
* {@code </servlet-mapping>}
* </pre>
* <p/>
* Alternatively, the DefaultBlockingServlet can be deployed as a Servlet
* Filter. This may be necessary in cases where an existing filter is configured
* in the web application, and that filter interferes with the Errai Bus
* requests. In this case, configuring DefaultBlockingServlet to handle
* {@code *.erraiBus} requests ahead of other filters in web.xml will solve the
* problem:
* <p/>
* <pre>
* {@code <filter>}
* {@code <filter-name>ErraiServlet</filter-name>}
* {@code <filter-class>org.jboss.errai.bus.server.servlet.DefaultBlockingServlet</filter-class>}
* {@code </filter>}
*
* {@code <filter-mapping>}
* {@code <filter-name>ErraiServlet</filter-name>}
* {@code <url-pattern>*.erraiBus</url-pattern>}
* {@code </filter-mapping>}
*
* {@code <!-- other filter-mapping and servlet-mapping elements go here -->}
* </pre>
*/
public class ChaosMonkeyServlet extends DefaultBlockingServlet {
private static final Logger log = getLogger(ChaosMonkeyServlet.class);
@Override
public void init(ServletConfig config) throws ServletException {
super.init(config);
}
@Override
public void initAsFilter(FilterConfig config) throws ServletException {
super.initAsFilter(config);
}
@Override
public void init(final FilterConfig filterConfig) throws ServletException {
super.initAsFilter(filterConfig);
}
/**
* Called by the server (via the <tt>service</tt> method) to allow a servlet to handle a GET request by supplying
* a response
*
* @param httpServletRequest
* - object that contains the request the client has made of the servlet
* @param httpServletResponse
* - object that contains the response the servlet sends to the client
*
* @throws java.io.IOException
* - if an input or output error is detected when the servlet handles the GET request
* @throws javax.servlet.ServletException
* - if the request for the GET could not be handled
*/
@Override
protected void doGet(final HttpServletRequest httpServletRequest, final HttpServletResponse httpServletResponse)
throws ServletException {
try {
if (Math.random() > 0.7d) {
httpServletResponse.setStatus(404);
httpServletResponse.getWriter().println("The chaos monkey strikes again!");
httpServletResponse.flushBuffer();
}
else if (Math.random() < 0.3d) {
httpServletResponse.setStatus(401);
httpServletResponse.getWriter().println("The chaos monkey strikes again!");
httpServletResponse.flushBuffer();
}
else {
super.doGet(httpServletRequest, httpServletResponse);
}
}
catch (IOException ioe) {
log.debug("Chaos Monkey ran into problem", ioe);
}
}
/**
* Called by the server (via the <code>service</code> method) to allow a servlet to handle a POST request, by
* sending the request
*
* @param httpServletRequest
* - object that contains the request the client has made of the servlet
* @param httpServletResponse
* - object that contains the response the servlet sends to the client
*
* @throws java.io.IOException
* - if an input or output error is detected when the servlet handles the request
* @throws javax.servlet.ServletException
* - if the request for the POST could not be handled
*/
@Override
protected void doPost(final HttpServletRequest httpServletRequest, final HttpServletResponse httpServletResponse) throws ServletException {
try {
if (Math.random() > 0.7d) {
httpServletResponse.setStatus(404);
httpServletResponse.getWriter().println("The chaos monkey strikes again!");
httpServletResponse.flushBuffer();
}
else if (Math.random() < 0.3d) {
httpServletResponse.setStatus(401);
httpServletResponse.getWriter().println("The chaos monkey strikes again!");
httpServletResponse.flushBuffer();
}
else {
super.doPost(httpServletRequest, httpServletResponse);
}
}
catch (IOException ioe) {
log.debug("Chaos Monkey ran into problem", ioe);
}
}
/**
* Services this request in the same way as it would be serviced if configured
* as a Servlet. Does not invoke any filters further down the chain. See the
* class-level comment for the reason why this servlet might be configured as a
* filter.
*/
@Override
public void doFilter(final ServletRequest request, final ServletResponse response, final FilterChain chain)
throws IOException, ServletException {
if (Math.random() > 0.7d) {
// response.setStatus(404);
response.getWriter().println("The chaos monkey strikes again!");
response.flushBuffer();
}
else {
super.doFilter(request, response, chain);
}
}
}