| /** |
| * 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; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * 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 |
| */ |
| public class ChoiceProcessor extends ServiceSupport implements AsyncProcessor, Navigate<Processor>, Traceable { |
| private static final transient Logger LOG = LoggerFactory.getLogger(ChoiceProcessor.class); |
| 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 (int i = 0; i < filters.size(); i++) { |
| FilterProcessor filter = filters.get(i); |
| Predicate predicate = filter.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 (LOG.isDebugEnabled()) { |
| LOG.debug("#{} - {} matches: {} for: {}", new Object[]{i, predicate, matches, exchange}); |
| } |
| |
| 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 filter.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); |
| } |
| } |