/*
 * Copyright 2002-2018 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
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package org.springframework.orm.jpa.support;

import java.util.concurrent.Callable;
import javax.persistence.EntityManagerFactory;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.orm.jpa.EntityManagerFactoryUtils;
import org.springframework.orm.jpa.EntityManagerHolder;
import org.springframework.transaction.support.TransactionSynchronizationManager;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.context.request.async.CallableProcessingInterceptor;
import org.springframework.web.context.request.async.DeferredResult;
import org.springframework.web.context.request.async.DeferredResultProcessingInterceptor;

An interceptor with asynchronous web requests used in OpenSessionInViewFilter and OpenSessionInViewInterceptor. Ensures the following: 1) The session is bound/unbound when "callable processing" is started 2) The session is closed if an async request times out or an error occurred
Author:Rossen Stoyanchev
Since:3.2.5
/** * An interceptor with asynchronous web requests used in OpenSessionInViewFilter and * OpenSessionInViewInterceptor. * * Ensures the following: * 1) The session is bound/unbound when "callable processing" is started * 2) The session is closed if an async request times out or an error occurred * * @author Rossen Stoyanchev * @since 3.2.5 */
class AsyncRequestInterceptor implements CallableProcessingInterceptor, DeferredResultProcessingInterceptor { private static final Log logger = LogFactory.getLog(AsyncRequestInterceptor.class); private final EntityManagerFactory emFactory; private final EntityManagerHolder emHolder; private volatile boolean timeoutInProgress; private volatile boolean errorInProgress; public AsyncRequestInterceptor(EntityManagerFactory emFactory, EntityManagerHolder emHolder) { this.emFactory = emFactory; this.emHolder = emHolder; } @Override public <T> void preProcess(NativeWebRequest request, Callable<T> task) { bindEntityManager(); } public void bindEntityManager() { this.timeoutInProgress = false; this.errorInProgress = false; TransactionSynchronizationManager.bindResource(this.emFactory, this.emHolder); } @Override public <T> void postProcess(NativeWebRequest request, Callable<T> task, Object concurrentResult) { TransactionSynchronizationManager.unbindResource(this.emFactory); } @Override public <T> Object handleTimeout(NativeWebRequest request, Callable<T> task) { this.timeoutInProgress = true; return RESULT_NONE; // give other interceptors a chance to handle the timeout } @Override public <T> Object handleError(NativeWebRequest request, Callable<T> task, Throwable t) { this.errorInProgress = true; return RESULT_NONE; // give other interceptors a chance to handle the error } @Override public <T> void afterCompletion(NativeWebRequest request, Callable<T> task) throws Exception { closeEntityManager(); } private void closeEntityManager() { if (this.timeoutInProgress || this.errorInProgress) { logger.debug("Closing JPA EntityManager after async request timeout/error"); EntityManagerFactoryUtils.closeEntityManager(this.emHolder.getEntityManager()); } } // Implementation of DeferredResultProcessingInterceptor methods @Override public <T> boolean handleTimeout(NativeWebRequest request, DeferredResult<T> deferredResult) { this.timeoutInProgress = true; return true; // give other interceptors a chance to handle the timeout } @Override public <T> boolean handleError(NativeWebRequest request, DeferredResult<T> deferredResult, Throwable t) { this.errorInProgress = true; return true; // give other interceptors a chance to handle the error } @Override public <T> void afterCompletion(NativeWebRequest request, DeferredResult<T> deferredResult) { closeEntityManager(); } }