/*
* Copyright (c) 2010-2014. Axon Framework
*
* 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.axonframework.correlation;
import org.axonframework.domain.Message;
import org.axonframework.domain.MetaData;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
/**
* CorrelationDataProvider implementation defines correlation headers by the header names. The headers from messages
* with these keys are returned as correlation data.
*
* @author Allard Buijze
* @since 2.3
*/
public class SimpleCorrelationDataProvider implements CorrelationDataProvider<Message> {
private final String[] headerNames;
/**
* Initializes the CorrelationDataProvider to return the meta data of messages with given <code>metaDataKeys</code>
* as correlation data.
*
* @param metaDataKeys The keys of the meta data entries from messages to return as correlation data
*/
public SimpleCorrelationDataProvider(String... metaDataKeys) {
this.headerNames = Arrays.copyOf(metaDataKeys, metaDataKeys.length);
}
@Override
public Map<String, ?> correlationDataFor(Message message) {
if (headerNames.length == 0) {
return Collections.emptyMap();
}
Map<String, Object> data = new HashMap<String, Object>();
final MetaData metaData = message.getMetaData();
for (String headerName : headerNames) {
if (metaData.containsKey(headerName)) {
data.put(headerName, metaData.get(headerName));
}
}
return data;
}
}