/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.camel.builder;
import java.util.function.BiFunction;
import org.apache.camel.Exchange;
import org.apache.camel.Message;
import org.apache.camel.processor.aggregate.AggregationStrategy;
import org.apache.camel.util.ObjectHelper;
public class AggregationStrategyClause<T> implements AggregationStrategy {
private final T parent;
private AggregationStrategy strategy;
public AggregationStrategyClause(T parent) {
this.parent = parent;
this.strategy = null;
}
@Override
public Exchange aggregate(Exchange oldExchange, Exchange newExchange) {
return ObjectHelper.notNull(strategy, "AggregationStrategy").aggregate(oldExchange, newExchange);
}
// *******************************
// Exchange
// *******************************
/**
* Define an aggregation strategy which targets the exchnage.
*/
public T exchange(final BiFunction<Exchange, Exchange, Exchange> function) {
strategy = function::apply;
return parent;
}
// *******************************
// Message
// *******************************
/**
* Define an aggregation strategy which targets Exchanges In Message.
*
* <blockquote><pre>{@code
* from("direct:aggregate")
* .aggregate()
* .message((old, new) -> {
* if (old == null) {
* return new;
* }
*
* String oldBody = old.getBody(String.class);
* String newBody = new.getBody(String.class);
*
* old.setBody(oldBody + "+" + newBody);
*
* return old;
* });
* }</pre></blockquote>
*/
public T message(final BiFunction<Message, Message, Message> function) {
return exchange((Exchange oldExchange, Exchange newExchange) -> {
Message oldMessage = oldExchange != null ? oldExchange.getIn() : null;
Message newMessage = ObjectHelper.notNull(newExchange, "NewExchange").getIn();
Message result = function.apply(oldMessage, newMessage);
if (oldExchange != null) {
oldExchange.setIn(result);
return oldExchange;
} else {
newExchange.setIn(result);
return newExchange;
}
});
}
// *******************************
// Body
// *******************************
/**
* Define an aggregation strategy which targets Exchanges In Body.
*
* <blockquote><pre>{@code
* from("direct:aggregate")
* .aggregate()
* .body((old, new) -> {
* if (old == null) {
* return new;
* }
*
* return old.toString() + new.toString();
* });
* }</pre></blockquote>
*/
public T body(final BiFunction<Object, Object, Object> function) {
return body(Object.class, function);
}
/**
* Define an aggregation strategy which targets Exchanges In Body.
*
* <blockquote><pre>{@code
* from("direct:aggregate")
* .aggregate()
* .body(String.class, (old, new) -> {
* if (old == null) {
* return new;
* }
*
* return old + new;
* });
* }</pre></blockquote>
*/
public <B> T body(final Class<B> type, final BiFunction<B, B, Object> function) {
return body(type, type, function);
}
/**
* Define an aggregation strategy which targets Exchanges In Body.
*/
public <O, N> T body(final Class<O> oldType, final Class<N> newType, final BiFunction<O, N, Object> function) {
return exchange((Exchange oldExchange, Exchange newExchange) -> {
Message oldMessage = oldExchange != null ? oldExchange.getIn() : null;
Message newMessage = ObjectHelper.notNull(newExchange, "NewExchange").getIn();
Object result = function.apply(
oldMessage != null ? oldMessage.getBody(oldType) : null,
newMessage != null ? newMessage.getBody(newType) : null);
if (oldExchange != null) {
oldExchange.getIn().setBody(result);
return oldExchange;
} else {
newExchange.getIn().setBody(result);
return newExchange;
}
});
}
}