org.springframework.web.context.request.RequestContextHolder Maven / Gradle / Ivy
/*
* Copyright 2002-2007 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.context.request;
/**
* Holder class to expose the web request in the form of a thread-bound
* {@link RequestAttributes} object.
*
* Use {@link RequestContextListener} or
* {@link org.springframework.web.filter.RequestContextFilter} to expose
* the current web request. Note that
* {@link org.springframework.web.servlet.DispatcherServlet} and
* {@link org.springframework.web.portlet.DispatcherPortlet} already
* expose the current request by default.
*
* @author Juergen Hoeller
* @author Rod Johnson
* @since 2.0
* @see RequestContextListener
* @see org.springframework.web.filter.RequestContextFilter
* @see org.springframework.web.servlet.DispatcherServlet
* @see org.springframework.web.portlet.DispatcherPortlet
*/
public abstract class RequestContextHolder {
private static final ThreadLocal requestAttributesHolder = new ThreadLocal();
private static final ThreadLocal inheritableRequestAttributesHolder = new InheritableThreadLocal();
/**
* Reset the RequestAttributes for the current thread.
*/
public static void resetRequestAttributes() {
requestAttributesHolder.set(null);
inheritableRequestAttributesHolder.set(null);
}
/**
* Bind the given RequestAttributes to the current thread,
* not exposing it as inheritable for child threads.
* @param attributes the RequestAttributes to expose
* @see #setRequestAttributes(RequestAttributes, boolean)
*/
public static void setRequestAttributes(RequestAttributes attributes) {
setRequestAttributes(attributes, false);
}
/**
* Bind the given RequestAttributes to the current thread.
* @param attributes the RequestAttributes to expose
* @param inheritable whether to expose the RequestAttributes as inheritable
* for child threads (using an {@link java.lang.InheritableThreadLocal})
*/
public static void setRequestAttributes(RequestAttributes attributes, boolean inheritable) {
if (inheritable) {
inheritableRequestAttributesHolder.set(attributes);
requestAttributesHolder.set(null);
}
else {
requestAttributesHolder.set(attributes);
inheritableRequestAttributesHolder.set(null);
}
}
/**
* Return the RequestAttributes currently bound to the thread.
* @return the RequestAttributes currently bound to the thread,
* or null if none bound
*/
public static RequestAttributes getRequestAttributes() {
RequestAttributes attributes = (RequestAttributes) requestAttributesHolder.get();
if (attributes == null) {
attributes = (RequestAttributes) inheritableRequestAttributesHolder.get();
}
return attributes;
}
/**
* Return the RequestAttributes currently bound to the thread.
* @return the RequestAttributes currently bound to the thread
* @throws IllegalStateException if no RequestAttributes object
* is bound to the current thread
*/
public static RequestAttributes currentRequestAttributes() throws IllegalStateException {
RequestAttributes attributes = getRequestAttributes();
if (attributes == null) {
throw new IllegalStateException("No thread-bound request found: " +
"Are you referring to request attributes outside of an actual web request? " +
"If you are actually operating within a web request and still receive this message," +
"your code is probably running outside of DispatcherServlet/DispatcherPortlet: " +
"In this case, use RequestContextListener or RequestContextFilter to expose the current request.");
}
return attributes;
}
}