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     */
017    package org.apache.camel.component;
018    
019    import org.apache.camel.Component;
020    import org.apache.camel.Processor;
021    import org.apache.camel.impl.ProcessorEndpoint;
022    import org.apache.commons.logging.Log;
023    import org.apache.commons.logging.LogFactory;
024    import org.springframework.core.io.DefaultResourceLoader;
025    import org.springframework.core.io.Resource;
026    import org.springframework.core.io.ResourceLoader;
027    
028    /**
029     * A useful base class for endpoints which depend on a resource
030     * such as things like Velocity or XQuery based components
031     *
032     * @version $Revision: 41334 $
033     */
034    public abstract class ResourceBasedEndpoint extends ProcessorEndpoint {
035        protected final transient Log log = LogFactory.getLog(getClass());
036        private final String resourceUri;
037        private ResourceLoader resourceLoader = new DefaultResourceLoader();
038        private Resource resource;
039    
040        public ResourceBasedEndpoint(String endpointUri, Component component, String resourceUri, Processor processor) {
041            super(endpointUri, component, processor);
042            this.resourceUri = resourceUri;
043        }
044    
045        protected ResourceBasedEndpoint(String endpointUri, Processor processor, String resourceUri) {
046            super(endpointUri, processor);
047            this.resourceUri = resourceUri;
048        }
049    
050        public Resource getResource() {
051            if (resource == null) {
052                resource = getResourceLoader().getResource(resourceUri);
053                if (resource == null) {
054                    throw new IllegalArgumentException("Could not find resource for URI: " + resourceUri + " using: " + getResourceLoader());
055                }
056            }
057            return resource;
058        }
059    
060        public ResourceLoader getResourceLoader() {
061            return resourceLoader;
062        }
063    
064        public void setResourceLoader(ResourceLoader resourceLoader) {
065            this.resourceLoader = resourceLoader;
066        }
067    }