/*
* 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.synapse.commons.evaluators.config;
import org.apache.axiom.om.OMElement;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.synapse.commons.evaluators.Evaluator;
import org.apache.synapse.commons.evaluators.EvaluatorConstants;
import org.apache.synapse.commons.evaluators.EvaluatorException;
import java.util.Map;
import java.util.HashMap;
/**
* Factories for creating Evaluators are found using the evaluator name. This class stores
* information about Evaluator Factories and their corresponding names. This is a Singleton class.
*/
public class EvaluatorFactoryFinder {
private static final Log log = LogFactory.getLog(EvaluatorFactoryFinder.class);
private static final EvaluatorFactoryFinder finder = new EvaluatorFactoryFinder();
private Map<String, EvaluatorFactory> factories = new HashMap<String, EvaluatorFactory>();
private EvaluatorFactoryFinder() {
factories.put(EvaluatorConstants.AND, new AndFactory());
factories.put(EvaluatorConstants.OR, new OrFactory());
factories.put(EvaluatorConstants.NOT, new NotFactory());
factories.put(EvaluatorConstants.MATCH, new MatchFactory());
factories.put(EvaluatorConstants.EQUAL, new EqualFactory());
}
/**
* Return and instance of the <code>EvaluatorFactoryFinder</code>.
* @return the EvaluatorFactoryFinder singleton
*/
public static EvaluatorFactoryFinder getInstance() {
return finder;
}
/**
* Retun an <code>EvaluatorFactory</code> for a given Evaluator name.
* @param name name of the Evaluator
* @return an EvaluatorFactory
*/
public EvaluatorFactory findEvaluatorFactory(String name) {
return factories.get(name);
}
/**
* Retun an <code>EvaluatorFactory</code> for a given Evaluator name.
* @param elem A XML element containing the evaluator configuration
* @return an Evaluator
* @throws org.apache.synapse.commons.evaluators.EvaluatorException if it cannot find
* a corresponding factory for creating an evaluator
*/
public Evaluator getEvaluator(OMElement elem) throws EvaluatorException {
EvaluatorFactory fac = findEvaluatorFactory(elem.getLocalName());
if (fac == null) {
handleException("Invalid configuration element: " + elem.getLocalName());
} else {
return fac.create(elem);
}
return null;
}
private void handleException(String message) throws EvaluatorException {
log.error(message);
throw new EvaluatorException(message);
}
}