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.component.file;
018
019import java.util.Comparator;
020import java.util.Iterator;
021import java.util.Map;
022
023import org.apache.camel.CamelContext;
024import org.apache.camel.Exchange;
025import org.apache.camel.impl.UriEndpointComponent;
026import org.apache.camel.util.CastUtils;
027import org.apache.camel.util.EndpointHelper;
028import org.apache.camel.util.ObjectHelper;
029import org.slf4j.Logger;
030import org.slf4j.LoggerFactory;
031
032import static org.apache.camel.util.ObjectHelper.isNotEmpty;
033
034/**
035 * Base class file component. To be extended.
036 */
037public abstract class GenericFileComponent<T> extends UriEndpointComponent {
038
039    protected Logger log = LoggerFactory.getLogger(getClass());
040
041    public GenericFileComponent() {
042        super(GenericFileEndpoint.class);
043    }
044
045    public GenericFileComponent(CamelContext context) {
046        super(context, GenericFileEndpoint.class);
047    }
048
049    protected GenericFileEndpoint<T> createEndpoint(String uri, String remaining, Map<String, Object> parameters) throws Exception {
050
051        // create the correct endpoint based on the protocol
052        final GenericFileEndpoint<T> endpoint;
053
054        // call to subclasses to build their custom version of a GenericFileEndpoint
055        endpoint = buildFileEndpoint(uri, remaining, parameters);
056
057        // sort by using file language
058        String sortBy = getAndRemoveParameter(parameters, "sortBy", String.class);
059        if (isNotEmpty(sortBy) && !EndpointHelper.isReferenceParameter(sortBy)) {
060            // we support nested sort groups so they should be chained
061            String[] groups = sortBy.split(";");
062            Iterator<String> it = CastUtils.cast(ObjectHelper.createIterator(groups));
063            Comparator<Exchange> comparator = createSortByComparator(it);
064            endpoint.setSortBy(comparator);
065        }
066        setProperties(endpoint.getConfiguration(), parameters);
067        setProperties(endpoint, parameters);
068
069        afterPropertiesSet(endpoint);
070
071        return endpoint;
072    }
073
074    /**
075     * A factory method for derived file components to create the endpoint
076     *
077     * @param uri the full URI of the endpoint
078     * @param remaining the remaining part of the URI without the query
079     *                parameters or component prefix
080     * @param parameters the optional parameters passed in
081     * @return a newly created endpoint or null if the endpoint cannot be
082     *         created based on the inputs
083     * @throws Exception can be thrown
084     */
085    protected abstract GenericFileEndpoint<T> buildFileEndpoint(String uri, String remaining, Map<String, Object> parameters) throws Exception;
086
087    /**
088     * A factory method for derived file components to perform validation of properties
089     *
090     * @param endpoint the endpoint
091     * @throws Exception can be thrown in case of validation errors
092     */
093    protected abstract void afterPropertiesSet(GenericFileEndpoint<T> endpoint) throws Exception;
094
095    /**
096     * Helper to create a sort comparator
097     *
098     * @param it iterator
099     * @return Comparator<Exchange>
100     */
101    private Comparator<Exchange> createSortByComparator(Iterator<String> it) {
102        if (!it.hasNext()) {
103            return null;
104        }
105
106        String group = it.next();
107
108        boolean reverse = group.startsWith("reverse:");
109        String reminder = reverse ? ifStartsWithReturnRemainder("reverse:", group) : group;
110
111        boolean ignoreCase = reminder.startsWith("ignoreCase:");
112        reminder = ignoreCase ? ifStartsWithReturnRemainder("ignoreCase:", reminder) : reminder;
113
114        ObjectHelper.notEmpty(reminder, "sortBy expression", this);
115
116        // recursive add nested sorters
117        return GenericFileDefaultSorter.sortByFileLanguage(getCamelContext(), 
118            reminder, reverse, ignoreCase, createSortByComparator(it));
119    }
120}