/**
* 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.processor;
import java.util.ArrayList;
import java.util.List;
import org.apache.camel.AsyncCallback;
import org.apache.camel.AsyncProcessor;
import org.apache.camel.Exchange;
import org.apache.camel.Navigate;
import org.apache.camel.Predicate;
import org.apache.camel.Processor;
import org.apache.camel.impl.ServiceSupport;
import org.apache.camel.impl.converter.AsyncProcessorTypeConverter;
import org.apache.camel.util.AsyncProcessorHelper;
import org.apache.camel.util.ServiceHelper;
/**
* Implements a Choice structure where one or more predicates are used which if
* they are true their processors are used, with a default otherwise clause used
* if none match.
*
* @version $Revision: 959391 $
*/
public class ChoiceProcessor extends ServiceSupport implements AsyncProcessor, Navigate<Processor>, Traceable {
private final List<FilterProcessor> filters;
private final AsyncProcessor otherwise;
public ChoiceProcessor(List<FilterProcessor> filters, Processor otherwise) {
this.filters = filters;
this.otherwise = AsyncProcessorTypeConverter.convert(otherwise);
}
public void process(Exchange exchange) throws Exception {
AsyncProcessorHelper.process(this, exchange);
}
public boolean process(Exchange exchange, AsyncCallback callback) {
for (FilterProcessor filterProcessor : filters) {
Predicate predicate = filterProcessor.getPredicate();
boolean matches = false;
try {
// ensure we handle exceptions thrown when matching predicate
if (predicate != null) {
matches = predicate.matches(exchange);
}
} catch (Throwable e) {
exchange.setException(e);
callback.done(true);
return true;
}
if (matches) {
// process next will also take care (has not null test) if next was a stop().
// stop() has no processor to execute, and thus we will end in a NPE
return filterProcessor.processNext(exchange, callback);
}
}
if (otherwise != null) {
return AsyncProcessorHelper.process(otherwise, exchange, callback);
} else {
callback.done(true);
return true;
}
}
@Override
public String toString() {
StringBuilder builder = new StringBuilder("choice{");
boolean first = true;
for (FilterProcessor processor : filters) {
if (first) {
first = false;
} else {
builder.append(", ");
}
builder.append("when ");
builder.append(processor.getPredicate().toString());
builder.append(": ");
builder.append(processor.getProcessor());
}
if (otherwise != null) {
builder.append(", otherwise: ");
builder.append(otherwise);
}
builder.append("}");
return builder.toString();
}
public String getTraceLabel() {
return "choice";
}
public List<FilterProcessor> getFilters() {
return filters;
}
public Processor getOtherwise() {
return otherwise;
}
public List<Processor> next() {
if (!hasNext()) {
return null;
}
List<Processor> answer = new ArrayList<Processor>();
if (filters != null) {
answer.addAll(filters);
}
if (otherwise != null) {
answer.add(otherwise);
}
return answer;
}
public boolean hasNext() {
return otherwise != null || (filters != null && !filters.isEmpty());
}
protected void doStart() throws Exception {
ServiceHelper.startServices(filters, otherwise);
}
protected void doStop() throws Exception {
ServiceHelper.stopServices(otherwise, filters);
}
}