001/* 002 * Copyright 2002-2016 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.web.servlet.mvc.method.annotation; 018 019import org.springframework.core.MethodParameter; 020import org.springframework.util.concurrent.ListenableFuture; 021import org.springframework.util.concurrent.ListenableFutureCallback; 022import org.springframework.web.context.request.NativeWebRequest; 023import org.springframework.web.context.request.async.DeferredResult; 024import org.springframework.web.context.request.async.WebAsyncUtils; 025import org.springframework.web.method.support.AsyncHandlerMethodReturnValueHandler; 026import org.springframework.web.method.support.ModelAndViewContainer; 027 028/** 029 * Handles return values of type 030 * {@link org.springframework.util.concurrent.ListenableFuture}. 031 * 032 * @author Rossen Stoyanchev 033 * @since 4.1 034 * @deprecated as of 4.3 {@link DeferredResultMethodReturnValueHandler} supports 035 * ListenableFuture return values via an adapter mechanism. 036 */ 037@Deprecated 038public class ListenableFutureReturnValueHandler implements AsyncHandlerMethodReturnValueHandler { 039 040 @Override 041 public boolean supportsReturnType(MethodParameter returnType) { 042 return ListenableFuture.class.isAssignableFrom(returnType.getParameterType()); 043 } 044 045 @Override 046 public boolean isAsyncReturnValue(Object returnValue, MethodParameter returnType) { 047 return (returnValue != null && returnValue instanceof ListenableFuture); 048 } 049 050 @Override 051 public void handleReturnValue(Object returnValue, MethodParameter returnType, 052 ModelAndViewContainer mavContainer, NativeWebRequest webRequest) throws Exception { 053 054 if (returnValue == null) { 055 mavContainer.setRequestHandled(true); 056 return; 057 } 058 059 final DeferredResult<Object> deferredResult = new DeferredResult<Object>(); 060 WebAsyncUtils.getAsyncManager(webRequest).startDeferredResultProcessing(deferredResult, mavContainer); 061 062 ListenableFuture<?> future = (ListenableFuture<?>) returnValue; 063 future.addCallback(new ListenableFutureCallback<Object>() { 064 @Override 065 public void onSuccess(Object result) { 066 deferredResult.setResult(result); 067 } 068 @Override 069 public void onFailure(Throwable ex) { 070 deferredResult.setErrorResult(ex); 071 } 072 }); 073 } 074 075}