/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.camel.impl;
import org.apache.camel.CamelContext;
import org.apache.camel.NoFactoryAvailableException;
import org.apache.camel.NoSuchLanguageException;
import org.apache.camel.spi.FactoryFinder;
import org.apache.camel.spi.Language;
import org.apache.camel.spi.LanguageResolver;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Default language resolver that looks for language factories in <b>META-INF/services/org/apache/camel/language/</b> and
* language resolvers in <b>META-INF/services/org/apache/camel/language/resolver/</b>.
*
* @version $Revision: 773945 $
*/
public class DefaultLanguageResolver implements LanguageResolver {
public static final String LANGUAGE_RESOURCE_PATH = "META-INF/services/org/apache/camel/language/";
public static final String LANGUAGE_RESOLVER_RESOURCE_PATH = LANGUAGE_RESOURCE_PATH + "resolver/";
private static final transient Log LOG = LogFactory.getLog(DefaultLanguageResolver.class);
protected FactoryFinder languageFactory;
protected FactoryFinder languageResolver;
@SuppressWarnings("unchecked")
public Language resolveLanguage(String name, CamelContext context) {
// lookup in registry first
Object bean = null;
try {
bean = context.getRegistry().lookup(name);
if (bean != null && getLog().isDebugEnabled()) {
getLog().debug("Found language: " + name + " in registry: " + bean);
}
} catch (Exception e) {
getLog().debug("Ignored error looking up bean: " + name + ". Error: " + e);
}
if (bean != null) {
if (bean instanceof Language) {
return (Language)bean;
}
// we do not throw the exception here and try to auto create a Language from META-INF
}
Class type = null;
try {
type = findLanguage(name, context);
} catch (NoFactoryAvailableException e) {
// ignore
} catch (Exception e) {
throw new IllegalArgumentException("Invalid URI, no Language registered for scheme: " + name, e);
}
if (type != null) {
if (Language.class.isAssignableFrom(type)) {
return (Language)context.getInjector().newInstance(type);
} else {
throw new IllegalArgumentException("Resolving language: " + name + " detected type conflict: Not a Language implementation. Found: " + type.getName());
}
} else {
// no specific language found then try fallback
return noSpecificLanguageFound(name, context);
}
}
@SuppressWarnings("unchecked")
protected Language noSpecificLanguageFound(String name, CamelContext context) {
Class type = null;
try {
type = findLanguageResolver("default", context);
} catch (NoFactoryAvailableException e) {
// ignore
} catch (Exception e) {
throw new IllegalArgumentException("Invalid URI, no LanguageResolver registered for scheme: " + name, e);
}
if (type != null) {
if (LanguageResolver.class.isAssignableFrom(type)) {
LanguageResolver resolver = (LanguageResolver)context.getInjector().newInstance(type);
return resolver.resolveLanguage(name, context);
} else {
throw new IllegalArgumentException("Resolving language: " + name + " detected type conflict: Not a LanguageResolver implementation. Found: " + type.getName());
}
}
throw new NoSuchLanguageException(name);
}
protected Class findLanguage(String name, CamelContext context) throws Exception {
if (languageFactory == null) {
languageFactory = context.getFactoryFinder(LANGUAGE_RESOURCE_PATH);
}
return languageFactory.findClass(name);
}
protected Class findLanguageResolver(String name, CamelContext context) throws Exception {
if (languageResolver == null) {
languageResolver = context.getFactoryFinder(LANGUAGE_RESOLVER_RESOURCE_PATH);
}
return languageResolver.findClass(name);
}
protected Log getLog() {
return LOG;
}
}