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 java.io.IOException; 020 021 import org.apache.camel.CamelContext; 022 import org.apache.camel.NoSuchLanguageException; 023 import org.apache.camel.spi.Language; 024 import org.apache.camel.spi.LanguageResolver; 025 import org.apache.camel.util.FactoryFinder; 026 import org.apache.camel.util.NoFactoryAvailableException; 027 import org.apache.commons.logging.Log; 028 import org.apache.commons.logging.LogFactory; 029 030 031 /** 032 * Default language resolver that looks for language factories in <b>META-INF/services/org/apache/camel/language/</b> and 033 * language resolvers in <b>META-INF/services/org/apache/camel/language/resolver/</b>. 034 * 035 * @version $Revision: 752787 $ 036 */ 037 public class DefaultLanguageResolver implements LanguageResolver { 038 protected static final FactoryFinder LANGUAGE_FACTORY = new FactoryFinder("META-INF/services/org/apache/camel/language/"); 039 protected static final FactoryFinder LANGUAGE_RESOLVER = new FactoryFinder("META-INF/services/org/apache/camel/language/resolver/"); 040 private static final transient Log LOG = LogFactory.getLog(DefaultLanguageResolver.class); 041 042 protected Log getLog() { 043 return LOG; 044 } 045 public Language resolveLanguage(String name, CamelContext context) { 046 Object bean = null; 047 try { 048 bean = context.getRegistry().lookup(name); 049 if (bean != null && getLog().isDebugEnabled()) { 050 getLog().debug("Found language: " + name + " in registry: " + bean); 051 } 052 } catch (Exception e) { 053 getLog().debug("Ignored error looking up bean: " + name + ". Error: " + e); 054 } 055 if (bean != null) { 056 if (bean instanceof Language) { 057 return (Language)bean; 058 } 059 // we do not throw the exception here and try to auto create a Language from META-INF 060 } 061 Class type = null; 062 try { 063 type = findLanguage(name); 064 } catch (NoFactoryAvailableException e) { 065 // ignore 066 } catch (Throwable e) { 067 throw new IllegalArgumentException("Invalid URI, no Language registered for scheme : " + name, e); 068 } 069 if (type != null) { 070 if (Language.class.isAssignableFrom(type)) { 071 return (Language)context.getInjector().newInstance(type); 072 } else { 073 throw new IllegalArgumentException("Type is not a Language implementation. Found: " + type.getName()); 074 } 075 } 076 return noSpecificLanguageFound(name, context); 077 } 078 079 protected Language noSpecificLanguageFound(String name, CamelContext context) { 080 Class type = null; 081 try { 082 type = findLanguageResolver("default"); 083 } catch (NoFactoryAvailableException e) { 084 // ignore 085 } catch (Throwable e) { 086 throw new IllegalArgumentException("Invalid URI, no Language registered for scheme : " + name, e); 087 } 088 if (type != null) { 089 if (LanguageResolver.class.isAssignableFrom(type)) { 090 LanguageResolver resolver = (LanguageResolver)context.getInjector().newInstance(type); 091 return resolver.resolveLanguage(name, context); 092 } else { 093 throw new IllegalArgumentException("Type is not a LanguageResolver implementation. Found: " + type.getName()); 094 } 095 } 096 throw new NoSuchLanguageException(name); 097 } 098 099 protected Class findLanguage(String name) throws Exception { 100 return LANGUAGE_FACTORY.findClass(name); 101 } 102 103 protected Class findLanguageResolver(String name) throws Exception { 104 return LANGUAGE_RESOLVER.findClass("default"); 105 } 106 }