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.model;
018
019import java.util.Comparator;
020import javax.xml.bind.annotation.XmlAccessType;
021import javax.xml.bind.annotation.XmlAccessorType;
022import javax.xml.bind.annotation.XmlAttribute;
023import javax.xml.bind.annotation.XmlRootElement;
024import javax.xml.bind.annotation.XmlTransient;
025
026import org.apache.camel.Expression;
027import org.apache.camel.Processor;
028import org.apache.camel.model.language.ExpressionDefinition;
029import org.apache.camel.processor.SortProcessor;
030import org.apache.camel.spi.Metadata;
031import org.apache.camel.spi.RouteContext;
032import org.apache.camel.util.ObjectHelper;
033
034import static org.apache.camel.builder.ExpressionBuilder.bodyExpression;
035
036/**
037 * Sorts the contents of the message
038 */
039@Metadata(label = "eip,routing")
040@XmlRootElement(name = "sort")
041@XmlAccessorType(XmlAccessType.FIELD)
042public class SortDefinition<T> extends NoOutputExpressionNode {
043    @XmlTransient
044    private Comparator<? super T> comparator;
045    @XmlAttribute
046    private String comparatorRef;
047
048    public SortDefinition() {
049    }
050
051    public SortDefinition(Expression expression) {
052        setExpression(ExpressionNodeHelper.toExpressionDefinition(expression));
053    }
054
055    public SortDefinition(Expression expression, Comparator<? super T> comparator) {
056        this(expression);
057        this.comparator = comparator;
058    }
059
060    @Override
061    public String toString() {
062        return "sort[" + getExpression() + " by: " + (comparatorRef != null ? "ref:" + comparatorRef : comparator) + "]";
063    }
064    
065    @Override
066    public String getLabel() {
067        return "sort[" + getExpression() + "]";
068    }
069
070    @Override
071    @SuppressWarnings("unchecked")
072    public Processor createProcessor(RouteContext routeContext) throws Exception {
073        // lookup in registry
074        if (ObjectHelper.isNotEmpty(comparatorRef)) {
075            comparator = routeContext.getCamelContext().getRegistry().lookupByNameAndType(comparatorRef, Comparator.class);
076        }
077
078        // if no comparator then default on to string representation
079        if (comparator == null) {
080            comparator = new Comparator<T>() {
081                public int compare(T o1, T o2) {
082                    return ObjectHelper.compare(o1, o2);
083                }
084            };
085        }
086
087        // if no expression provided then default to body expression
088        Expression exp;
089        if (getExpression() == null) {
090            exp = bodyExpression();
091        } else {
092            exp = getExpression().createExpression(routeContext);
093        }
094        return new SortProcessor<T>(exp, getComparator());
095    }
096
097    /**
098     * Optional expression to sort by something else than the message body
099     */
100    @Override
101    public void setExpression(ExpressionDefinition expression) {
102        // override to include javadoc what the expression is used for
103        super.setExpression(expression);
104    }
105
106    public Comparator<? super T> getComparator() {
107        return comparator;
108    }
109
110    public void setComparator(Comparator<T> comparator) {
111        this.comparator = comparator;
112    }
113
114    public String getComparatorRef() {
115        return comparatorRef;
116    }
117
118    public void setComparatorRef(String comparatorRef) {
119        this.comparatorRef = comparatorRef;
120    }
121
122    /**
123     * Sets the comparator to use for sorting
124     *
125     * @param comparator  the comparator to use for sorting
126     * @return the builder
127     */
128    public SortDefinition<T> comparator(Comparator<T> comparator) {
129        setComparator(comparator);
130        return this;
131    }
132
133    /**
134     * Sets a reference to lookup for the comparator to use for sorting
135     *
136     * @param ref reference for the comparator
137     * @return the builder
138     */
139    public SortDefinition<T> comparatorRef(String ref) {
140        setComparatorRef(ref);
141        return this;
142    }
143}