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.Collections;
020import java.util.Comparator;
021import java.util.List;
022
023import org.apache.camel.AsyncCallback;
024import org.apache.camel.AsyncProcessor;
025import org.apache.camel.Exchange;
026import org.apache.camel.Expression;
027import org.apache.camel.Message;
028import org.apache.camel.spi.IdAware;
029import org.apache.camel.support.ServiceSupport;
030import org.apache.camel.util.AsyncProcessorHelper;
031
032/**
033 * A processor that sorts the expression using a comparator
034 */
035public class SortProcessor<T> extends ServiceSupport implements AsyncProcessor, Traceable, IdAware {
036
037    private String id;
038    private final Expression expression;
039    private final Comparator<? super T> comparator;
040
041    public SortProcessor(Expression expression, Comparator<? super T> comparator) {
042        this.expression = expression;
043        this.comparator = comparator;
044    }
045
046    public void process(Exchange exchange) throws Exception {
047        AsyncProcessorHelper.process(this, exchange);
048    }
049
050    @Override
051    public boolean process(Exchange exchange, AsyncCallback callback) {
052        try {
053            Message in = exchange.getIn();
054
055            @SuppressWarnings("unchecked")
056            List<T> list = expression.evaluate(exchange, List.class);
057            Collections.sort(list, comparator);
058
059            if (exchange.getPattern().isOutCapable()) {
060                Message out = exchange.getOut();
061                out.copyFrom(in);
062                out.setBody(list);
063            } else {
064                in.setBody(list);
065            }
066        } catch (Exception e) {
067            exchange.setException(e);
068        }
069
070        callback.done(true);
071        return true;
072    }
073
074    public String toString() {
075        return "Sort[" + expression + "]";
076    }
077
078    @Override
079    public String getTraceLabel() {
080        return "sort[" + expression + "]";
081    }
082
083    public String getId() {
084        return id;
085    }
086
087    public void setId(String id) {
088        this.id = id;
089    }
090
091    public Expression getExpression() {
092        return expression;
093    }
094
095    public Comparator<? super T> getComparator() {
096        return comparator;
097    }
098
099    @Override
100    protected void doStart() throws Exception {
101        // noop
102    }
103
104    @Override
105    protected void doStop() throws Exception {
106        // noop
107    }
108}
109
110