blueprint/blueprint-jexl-evaluator/src/main/java/org/apache/aries/blueprint/jexl/evaluator/JexlPropertyEvaluator.java

/**
 *  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.aries.blueprint.jexl.evaluator;

import java.util.*;

import org.apache.aries.blueprint.ext.evaluator.PropertyEvaluatorExt;
import org.apache.commons.jexl2.Expression;
import org.apache.commons.jexl2.JexlEngine;
import org.apache.commons.jexl2.MapContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class JexlPropertyEvaluator implements PropertyEvaluatorExt {

    private static final Logger LOGGER = LoggerFactory.getLogger(JexlPropertyEvaluator.class);

    public Object evaluate(String expression, Map<String, Object> properties) {
        try {
            JexlEngine engine = new JexlEngine();
            MapContext context = new MapContext(properties);
            Expression exp = engine.createExpression(expression);
            return exp.evaluate(context);
        } catch (Exception e) {
            LOGGER.info("Could not evaluate expression: {}", expression);
            LOGGER.info("Exception:", e);
            return null;
        }
    }

}