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.impl;
018
019import java.io.IOException;
020
021import org.apache.camel.CamelContext;
022import org.apache.camel.ExtendedCamelContext;
023import org.apache.camel.NoFactoryAvailableException;
024import org.apache.camel.RuntimeCamelException;
025import org.apache.camel.spi.FactoryFinder;
026import org.apache.camel.spi.XMLRoutesDefinitionLoader;
027import org.slf4j.Logger;
028import org.slf4j.LoggerFactory;
029
030/**
031 * Factory to create the {@link XMLRoutesDefinitionLoader} implementation to be used.
032 *
033 * @see XMLRoutesDefinitionLoader
034 */
035public class XMLRoutesDefinitionLoaderResolver {
036
037    public static final String RESOURCE_PATH = "META-INF/services/org/apache/camel/";
038
039    private static final Logger LOG = LoggerFactory.getLogger(XMLRoutesDefinitionLoaderResolver.class);
040
041    private FactoryFinder factoryFinder;
042
043    public XMLRoutesDefinitionLoader resolve(CamelContext context) {
044        // use factory finder to find a custom implementations
045        Class<?> type = null;
046        try {
047            type = findFactory("xmlroutes-loader", context);
048        } catch (Exception e) {
049            // ignore
050        }
051
052        if (type != null) {
053            if (LOG.isDebugEnabled()) {
054                LOG.debug("Found XMLRoutesDefinitionLoader: {} via: {}{}", type.getName(), factoryFinder.getResourcePath(), "xmlroutes-loader");
055            }
056            if (XMLRoutesDefinitionLoader.class.isAssignableFrom(type)) {
057                XMLRoutesDefinitionLoader answer = (XMLRoutesDefinitionLoader) context.getInjector().newInstance(type, false);
058                LOG.info("Detected and using XMLRoutesDefinitionLoader: {}", answer);
059                return answer;
060            } else {
061                throw new IllegalArgumentException("Type is not a XMLRoutesDefinitionLoader implementation. Found: " + type.getName());
062            }
063        }
064
065        throw new RuntimeCamelException("Cannot find XML routes loader in classpath. Add either camel-xml-io or camel-xml-jaxb to the classpath.");
066    }
067
068    private Class<?> findFactory(String name, CamelContext context) throws IOException {
069        if (factoryFinder == null) {
070            factoryFinder = context.adapt(ExtendedCamelContext.class).getFactoryFinder(RESOURCE_PATH);
071        }
072        return factoryFinder.findClass(name).orElse(null);
073    }
074
075}
076