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.impl;
018    
019    import org.apache.camel.CamelContext;
020    import org.apache.camel.NoSuchLanguageException;
021    import org.apache.camel.spi.Language;
022    import org.apache.camel.spi.LanguageResolver;
023    import org.apache.camel.util.FactoryFinder;
024    import org.apache.camel.util.NoFactoryAvailableException;
025    
026    /**
027     * @version $Revision: 35332 $
028     */
029    public class DefaultLanguageResolver implements LanguageResolver {
030        protected static final FactoryFinder LANGUAGE_FACTORY = new FactoryFinder("META-INF/services/org/apache/camel/language/");
031        protected static final FactoryFinder LANGUAGE_RESOLVER = new FactoryFinder("META-INF/services/org/apache/camel/language/resolver/");
032    
033        public Language resolveLanguage(String name, CamelContext context) {
034            Class type = null;
035            try {
036                type = LANGUAGE_FACTORY.findClass(name);
037            } catch (NoFactoryAvailableException e) {
038                // ignore
039            } catch (Throwable e) {
040                throw new IllegalArgumentException("Invalid URI, no Language registered for scheme : " + name, e);
041            }
042            if (type != null) {
043                if (Language.class.isAssignableFrom(type)) {
044                    return (Language)context.getInjector().newInstance(type);
045                } else {
046                    throw new IllegalArgumentException("Type is not a Language implementation. Found: " + type.getName());
047                }
048            }
049            return noSpecificLanguageFound(name, context);
050        }
051    
052        protected Language noSpecificLanguageFound(String name, CamelContext context) {
053            Class type = null;
054            try {
055                type = LANGUAGE_RESOLVER.findClass("default");
056            } catch (NoFactoryAvailableException e) {
057                // ignore
058            } catch (Throwable e) {
059                throw new IllegalArgumentException("Invalid URI, no Language registered for scheme : " + name, e);
060            }
061            if (type != null) {
062                if (LanguageResolver.class.isAssignableFrom(type)) {
063                    LanguageResolver resolver = (LanguageResolver)context.getInjector().newInstance(type);
064                    return resolver.resolveLanguage(name, context);
065                } else {
066                    throw new IllegalArgumentException("Type is not a LanguageResolver implementation. Found: " + type.getName());
067                }
068            }
069            throw new NoSuchLanguageException(name);
070        }
071    }