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.apache.camel.util.StringHelper;
030import org.slf4j.Logger;
031import org.slf4j.LoggerFactory;
032
033import static org.apache.camel.util.ObjectHelper.isNotEmpty;
034
035/**
036 * Base class file component. To be extended.
037 */
038public abstract class GenericFileComponent<T> extends UriEndpointComponent {
039
040    protected Logger log = LoggerFactory.getLogger(getClass());
041
042    public GenericFileComponent() {
043        super(GenericFileEndpoint.class);
044    }
045
046    public GenericFileComponent(CamelContext context) {
047        super(context, GenericFileEndpoint.class);
048    }
049
050    protected GenericFileEndpoint<T> createEndpoint(String uri, String remaining, Map<String, Object> parameters) throws Exception {
051
052        // create the correct endpoint based on the protocol
053        final GenericFileEndpoint<T> endpoint;
054
055        // call to subclasses to build their custom version of a GenericFileEndpoint
056        endpoint = buildFileEndpoint(uri, remaining, parameters);
057
058        // sort by using file language
059        String sortBy = getAndRemoveParameter(parameters, "sortBy", String.class);
060        if (isNotEmpty(sortBy) && !EndpointHelper.isReferenceParameter(sortBy)) {
061            // we support nested sort groups so they should be chained
062            String[] groups = sortBy.split(";");
063            Iterator<String> it = CastUtils.cast(ObjectHelper.createIterator(groups));
064            Comparator<Exchange> comparator = createSortByComparator(it);
065            endpoint.setSortBy(comparator);
066        }
067        setProperties(endpoint.getConfiguration(), parameters);
068        setProperties(endpoint, parameters);
069
070        afterPropertiesSet(endpoint);
071
072        return endpoint;
073    }
074
075    /**
076     * A factory method for derived file components to create the endpoint
077     *
078     * @param uri the full URI of the endpoint
079     * @param remaining the remaining part of the URI without the query
080     *                parameters or component prefix
081     * @param parameters the optional parameters passed in
082     * @return a newly created endpoint or null if the endpoint cannot be
083     *         created based on the inputs
084     * @throws Exception can be thrown
085     */
086    protected abstract GenericFileEndpoint<T> buildFileEndpoint(String uri, String remaining, Map<String, Object> parameters) throws Exception;
087
088    /**
089     * A factory method for derived file components to perform validation of properties
090     *
091     * @param endpoint the endpoint
092     * @throws Exception can be thrown in case of validation errors
093     */
094    protected abstract void afterPropertiesSet(GenericFileEndpoint<T> endpoint) throws Exception;
095
096    /**
097     * Helper to create a sort comparator
098     *
099     * @param it iterator
100     * @return Comparator<Exchange>
101     */
102    private Comparator<Exchange> createSortByComparator(Iterator<String> it) {
103        if (!it.hasNext()) {
104            return null;
105        }
106
107        String group = it.next();
108
109        boolean reverse = group.startsWith("reverse:");
110        String reminder = reverse ? ifStartsWithReturnRemainder("reverse:", group) : group;
111
112        boolean ignoreCase = reminder.startsWith("ignoreCase:");
113        reminder = ignoreCase ? ifStartsWithReturnRemainder("ignoreCase:", reminder) : reminder;
114
115        StringHelper.notEmpty(reminder, "sortBy expression", this);
116
117        // recursive add nested sorters
118        return GenericFileDefaultSorter.sortByFileLanguage(getCamelContext(), 
119            reminder, reverse, ignoreCase, createSortByComparator(it));
120    }
121}