/*
 * Copyright 2002-2015 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.servlet;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Interface to be implemented by objects that can resolve exceptions thrown during
 * handler mapping or execution, in the typical case to error views. Implementors are
 * typically registered as beans in the application context.
 *
 * <p>Error views are analogous to JSP error pages but can be used with any kind of
 * exception including any checked exception, with potentially fine-grained mappings for
 * specific handlers.
 *
 * @author Juergen Hoeller
 * @since 22.11.2003
 */
public interface HandlerExceptionResolver {

	/**
	 * Try to resolve the given exception that got thrown during handler execution,
	 * returning a {@link ModelAndView} that represents a specific error page if appropriate.
	 * <p>The returned {@code ModelAndView} may be {@linkplain ModelAndView#isEmpty() empty}
	 * to indicate that the exception has been resolved successfully but that no view
	 * should be rendered, for instance by setting a status code.
	 * @param request current HTTP request
	 * @param response current HTTP response
	 * @param handler the executed handler, or {@code null} if none chosen at the
	 * time of the exception (for example, if multipart resolution failed)
	 * @param ex the exception that got thrown during handler execution
	 * @return a corresponding {@code ModelAndView} to forward to, or {@code null}
	 * for default processing
	 */
	ModelAndView resolveException(
			HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex);

}
