requestcontextholder.java

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/*
 * Copyright 2002-2005 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;



/**
 * Helper class to manage a thread-bound HttpServletRequest.
 *
 * @author Rod Johnson
 * @author Juergen Hoeller
 * @since 2.0
 * @see RequestContextListener
 * @see org.springframework.web.filter.RequestContextFilter
 */
public abstract class RequestContextHolder  {
	
	private static final ThreadLocal requestAttributesHolder = new InheritableThreadLocal();


	/**
	 * Bind the given RequestAttributes to the current thread.
	 * @param accessor the RequestAttributes to expose
	 */
	public static void setRequestAttributes(RequestAttributes accessor) {
		RequestContextHolder.requestAttributesHolder.set(accessor);
	}

	/**
	 * Return the RequestAttributes currently bound to the thread.
	 * @return the RequestAttributes currently bound to the thread,
	 * or <code>null</code>
	 */
	public static RequestAttributes getRequestAttributes() {
		return (RequestAttributes) requestAttributesHolder.get();
	}

	/**
	 * Return the RequestAttributes currently bound to the thread.
	 * @return the RequestAttributes currently bound to the thread
	 * @throws IllegalStateException if no RequestAttributes is bound
	 * to the current thread
	 */
	public static RequestAttributes currentRequestAttributes() throws IllegalStateException {
		RequestAttributes accessor = (RequestAttributes) requestAttributesHolder.get();
		if (accessor == null) {
			throw new IllegalStateException("No thread-bound request: use RequestContextFilter");
		}
		return accessor;
	}

}