/*
* Copyright 2006-2007 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.batch.integration.async;
import org.springframework.batch.core.StepExecution;
import org.springframework.batch.core.scope.context.StepContext;
import org.springframework.batch.core.scope.context.StepSynchronizationManager;
import org.springframework.integration.Message;
import org.springframework.integration.MessageChannel;
import org.springframework.integration.channel.ChannelInterceptor;
import org.springframework.integration.channel.interceptor.ChannelInterceptorAdapter;
import org.springframework.integration.support.MessageBuilder;
/**
* A {@link ChannelInterceptor} that adds the current {@link StepExecution} (if
* there is one) as a header to the message. Downstream asynchronous handlers
* can then take advantage of the step context without needing to be step
* scoped, which is a problem for handlers executing in another thread because
* the scope context is not available.
*
* @author Dave Syer
*
*/
public class StepExecutionInterceptor extends ChannelInterceptorAdapter {
/**
* The name of the header
*/
public static final String STEP_EXECUTION = "stepExecution";
@Override
public Message<?> preSend(Message<?> message, MessageChannel channel) {
StepContext context = StepSynchronizationManager.getContext();
if (context == null) {
return message;
}
return MessageBuilder.fromMessage(message).setHeader(STEP_EXECUTION, context.getStepExecution()).build();
}
}