org.springframework.web.context.request.async.WebAsyncTask Maven / Gradle / Ivy
/*
* 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
* limitations under the License.
*/
package org.springframework.web.context.request.async;
import java.util.concurrent.Callable;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.core.task.AsyncTaskExecutor;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.web.context.request.NativeWebRequest;
/**
* Holder for a {@link Callable}, a timeout value, and a task executor.
*
* @author Rossen Stoyanchev
* @author Juergen Hoeller
* @since 3.2
* @param the value type
*/
public class WebAsyncTask implements BeanFactoryAware {
private final Callable callable;
private Long timeout;
private AsyncTaskExecutor executor;
private String executorName;
private BeanFactory beanFactory;
private Callable timeoutCallback;
private Callable errorCallback;
private Runnable completionCallback;
/**
* Create a {@code WebAsyncTask} wrapping the given {@link Callable}.
* @param callable the callable for concurrent handling
*/
public WebAsyncTask(Callable callable) {
Assert.notNull(callable, "Callable must not be null");
this.callable = callable;
}
/**
* Create a {@code WebAsyncTask} with a timeout value and a {@link Callable}.
* @param timeout a timeout value in milliseconds
* @param callable the callable for concurrent handling
*/
public WebAsyncTask(long timeout, Callable callable) {
this(callable);
this.timeout = timeout;
}
/**
* Create a {@code WebAsyncTask} with a timeout value, an executor name, and a {@link Callable}.
* @param timeout timeout value in milliseconds; ignored if {@code null}
* @param executorName the name of an executor bean to use
* @param callable the callable for concurrent handling
*/
public WebAsyncTask(@Nullable Long timeout, String executorName, Callable callable) {
this(callable);
Assert.notNull(executorName, "Executor name must not be null");
this.executorName = executorName;
this.timeout = timeout;
}
/**
* Create a {@code WebAsyncTask} with a timeout value, an executor instance, and a Callable.
* @param timeout timeout value in milliseconds; ignored if {@code null}
* @param executor the executor to use
* @param callable the callable for concurrent handling
*/
public WebAsyncTask(@Nullable Long timeout, AsyncTaskExecutor executor, Callable callable) {
this(callable);
Assert.notNull(executor, "Executor must not be null");
this.executor = executor;
this.timeout = timeout;
}
/**
* Return the {@link Callable} to use for concurrent handling (never {@code null}).
*/
public Callable getCallable() {
return this.callable;
}
/**
* Return the timeout value in milliseconds, or {@code null} if no timeout is set.
*/
@Nullable
public Long getTimeout() {
return this.timeout;
}
/**
* A {@link BeanFactory} to use for resolving an executor name.
* This factory reference will automatically be set when
* {@code WebAsyncTask} is used within a Spring MVC controller.
*/
public void setBeanFactory(BeanFactory beanFactory) {
this.beanFactory = beanFactory;
}
/**
* Return the AsyncTaskExecutor to use for concurrent handling,
* or {@code null} if none specified.
*/
@Nullable
public AsyncTaskExecutor getExecutor() {
if (this.executor != null) {
return this.executor;
}
else if (this.executorName != null) {
Assert.state(this.beanFactory != null, "BeanFactory is required to look up an executor bean by name");
return this.beanFactory.getBean(this.executorName, AsyncTaskExecutor.class);
}
else {
return null;
}
}
/**
* Register code to invoke when the async request times out.
*
This method is called from a container thread when an async request times
* out before the {@code Callable} has completed. The callback is executed in
* the same thread and therefore should return without blocking. It may return
* an alternative value to use, including an {@link Exception} or return
* {@link CallableProcessingInterceptor#RESULT_NONE RESULT_NONE}.
*/
public void onTimeout(Callable callback) {
this.timeoutCallback = callback;
}
/**
* Register code to invoke for an error during async request processing.
* This method is called from a container thread when an error occurred
* while processing an async request before the {@code Callable} has
* completed. The callback is executed in the same thread and therefore
* should return without blocking. It may return an alternative value to
* use, including an {@link Exception} or return
* {@link CallableProcessingInterceptor#RESULT_NONE RESULT_NONE}.
* @since 5.0
*/
public void onError(Callable callback) {
this.errorCallback = callback;
}
/**
* Register code to invoke when the async request completes.
* This method is called from a container thread when an async request
* completed for any reason, including timeout and network error.
*/
public void onCompletion(Runnable callback) {
this.completionCallback = callback;
}
CallableProcessingInterceptor getInterceptor() {
return new CallableProcessingInterceptor() {
@Override
public Object handleTimeout(NativeWebRequest request, Callable task) throws Exception {
return (timeoutCallback != null ? timeoutCallback.call() : CallableProcessingInterceptor.RESULT_NONE);
}
@Override
public Object handleError(NativeWebRequest request, Callable task, Throwable t) throws Exception {
return (errorCallback != null ? errorCallback.call() : CallableProcessingInterceptor.RESULT_NONE);
}
@Override
public void afterCompletion(NativeWebRequest request, Callable task) throws Exception {
if (completionCallback != null) {
completionCallback.run();
}
}
};
}
}