001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.camel.processor;
018
019import java.util.Comparator;
020import java.util.List;
021
022import org.apache.camel.AsyncCallback;
023import org.apache.camel.AsyncProcessor;
024import org.apache.camel.Exchange;
025import org.apache.camel.Expression;
026import org.apache.camel.Message;
027import org.apache.camel.spi.IdAware;
028import org.apache.camel.support.ServiceSupport;
029import org.apache.camel.util.AsyncProcessorHelper;
030
031/**
032 * A processor that sorts the expression using a comparator
033 */
034public class SortProcessor<T> extends ServiceSupport implements AsyncProcessor, Traceable, IdAware {
035
036    private String id;
037    private final Expression expression;
038    private final Comparator<? super T> comparator;
039
040    public SortProcessor(Expression expression, Comparator<? super T> comparator) {
041        this.expression = expression;
042        this.comparator = comparator;
043    }
044
045    public void process(Exchange exchange) throws Exception {
046        AsyncProcessorHelper.process(this, exchange);
047    }
048
049    @Override
050    public boolean process(Exchange exchange, AsyncCallback callback) {
051        try {
052            Message in = exchange.getIn();
053
054            @SuppressWarnings("unchecked")
055            List<T> list = expression.evaluate(exchange, List.class);
056            list.sort(comparator);
057
058            if (exchange.getPattern().isOutCapable()) {
059                Message out = exchange.getOut();
060                out.copyFrom(in);
061                out.setBody(list);
062            } else {
063                in.setBody(list);
064            }
065        } catch (Exception e) {
066            exchange.setException(e);
067        }
068
069        callback.done(true);
070        return true;
071    }
072
073    public String toString() {
074        return "Sort[" + expression + "]";
075    }
076
077    @Override
078    public String getTraceLabel() {
079        return "sort[" + expression + "]";
080    }
081
082    public String getId() {
083        return id;
084    }
085
086    public void setId(String id) {
087        this.id = id;
088    }
089
090    public Expression getExpression() {
091        return expression;
092    }
093
094    public Comparator<? super T> getComparator() {
095        return comparator;
096    }
097
098    @Override
099    protected void doStart() throws Exception {
100        // noop
101    }
102
103    @Override
104    protected void doStop() throws Exception {
105        // noop
106    }
107}
108
109