/**
* Copyright 2012 Netflix, Inc.
*
* 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 com.netflix.hystrix.contrib.requestservlet;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import com.netflix.hystrix.strategy.concurrency.HystrixRequestContext;
/**
* Initializes the {@link HystrixRequestContext} at the beginning of each HTTP request and then cleans it up at the end.
* <p>
* Install by adding the following lines to your project web.xml:
* <p>
*
* <pre>
* {@code
* <filter>
* <display-name>HystrixRequestContextServletFilter</display-name>
* <filter-name>HystrixRequestContextServletFilter</filter-name>
* <filter-class>com.netflix.hystrix.contrib.requestservlet.HystrixRequestContextServletFilter</filter-class>
* </filter>
* <filter-mapping>
* <filter-name>HystrixRequestContextServletFilter</filter-name>
* <url-pattern>/*</url-pattern>
* </filter-mapping>
* }
* </pre>
*/
public class HystrixRequestContextServletFilter implements Filter {
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
HystrixRequestContext context = HystrixRequestContext.initializeContext();
try {
chain.doFilter(request, response);
} finally {
context.shutdown();
}
}
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void destroy() {
}
}