/*
* Copyright 2002-2009 the original author or authors.
*
* 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.springframework.web.filter;
import java.io.IOException;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.context.i18n.LocaleContextHolder;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
/**
* Servlet 2.3 Filter that exposes the request to the current thread,
* through both {@link org.springframework.context.i18n.LocaleContextHolder} and
* {@link RequestContextHolder}. To be registered as filter in <code>web.xml</code>.
*
* <p>Alternatively, Spring's {@link org.springframework.web.context.request.RequestContextListener}
* and Spring's {@link org.springframework.web.servlet.DispatcherServlet} also expose
* the same request context to the current thread.
*
* <p>This filter is mainly for use with third-party servlets, e.g. the JSF FacesServlet.
* Within Spring's own web support, DispatcherServlet's processing is perfectly sufficient.
*
* @author Juergen Hoeller
* @author Rod Johnson
* @since 2.0
* @see org.springframework.context.i18n.LocaleContextHolder
* @see org.springframework.web.context.request.RequestContextHolder
* @see org.springframework.web.context.request.RequestContextListener
* @see org.springframework.web.servlet.DispatcherServlet
*/
public class RequestContextFilter extends OncePerRequestFilter {
private boolean threadContextInheritable = false;
/**
* Set whether to expose the LocaleContext and RequestAttributes as inheritable
* for child threads (using an {@link java.lang.InheritableThreadLocal}).
* <p>Default is "false", to avoid side effects on spawned background threads.
* Switch this to "true" to enable inheritance for custom child threads which
* are spawned during request processing and only used for this request
* (that is, ending after their initial task, without reuse of the thread).
* <p><b>WARNING:</b> Do not use inheritance for child threads if you are
* accessing a thread pool which is configured to potentially add new threads
* on demand (e.g. a JDK {@link java.util.concurrent.ThreadPoolExecutor}),
* since this will expose the inherited context to such a pooled thread.
*/
public void setThreadContextInheritable(boolean threadContextInheritable) {
this.threadContextInheritable = threadContextInheritable;
}
@Override
protected void doFilterInternal(
HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
throws ServletException, IOException {
ServletRequestAttributes attributes = new ServletRequestAttributes(request);
LocaleContextHolder.setLocale(request.getLocale(), this.threadContextInheritable);
RequestContextHolder.setRequestAttributes(attributes, this.threadContextInheritable);
if (logger.isDebugEnabled()) {
logger.debug("Bound request context to thread: " + request);
}
try {
filterChain.doFilter(request, response);
}
finally {
LocaleContextHolder.resetLocaleContext();
RequestContextHolder.resetRequestAttributes();
attributes.requestCompleted();
if (logger.isDebugEnabled()) {
logger.debug("Cleared thread-bound request context: " + request);
}
}
}
}
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