/*
* Copyright 2014 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.xd.integration.hadoop.outbound;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.data.hadoop.store.DataStoreWriter;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageHandlingException;
import org.springframework.util.Assert;
/**
* Spring Integration {@code MessageHandler} handling {@code Message} writing into hdfs using {@code DataStoreWriter}.
*
* @author Janne Valkealahti
*/
public class HdfsDataStoreMessageHandler extends HdfsStoreMessageHandler {
private static final Log logger = LogFactory.getLog(HdfsDataStoreMessageHandler.class);
private DataStoreWriter<String> storeWriter;
/**
* Instantiates a new hdfs data store message handler.
*
* @param storeWriter the store writer
*/
public HdfsDataStoreMessageHandler(DataStoreWriter<String> storeWriter) {
Assert.notNull(storeWriter, "Writer must be set");
this.storeWriter = storeWriter;
}
@Override
protected void onInit() throws Exception {
super.onInit();
Assert.notNull(storeWriter, "Data Writer must be set");
}
@Override
protected void doStop() {
try {
if (storeWriter != null) {
storeWriter.close();
storeWriter = null;
}
}
catch (Exception e) {
logger.error("Error closing writer", e);
}
};
@Override
protected void doWrite(Message<?> message) throws Exception {
Assert.notNull(storeWriter, "Writer already closed");
Object payload = message.getPayload();
if (payload instanceof String) {
storeWriter.write((String) payload);
}
else {
throw new MessageHandlingException(message,
"message not a String");
}
}
}