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 */
017package org.apache.camel.processor;
018
019import org.apache.camel.AsyncCallback;
020import org.apache.camel.AsyncProcessor;
021import org.apache.camel.Exchange;
022import org.apache.camel.Expression;
023import org.apache.camel.Traceable;
024import org.apache.camel.spi.IdAware;
025import org.apache.camel.support.ServiceSupport;
026import org.apache.camel.util.AsyncProcessorHelper;
027import org.apache.camel.util.CamelLogger;
028
029/**
030 * A processor which evaluates an {@link Expression} and logs it.
031 *
032 * @version 
033 */
034public class LogProcessor extends ServiceSupport implements AsyncProcessor, Traceable, IdAware {
035
036    private String id;
037    private final Expression expression;
038    private final CamelLogger logger;
039
040    public LogProcessor(Expression expression, CamelLogger logger) {
041        this.expression = expression;
042        this.logger = logger;
043    }
044
045    public void process(Exchange exchange) throws Exception {
046        AsyncProcessorHelper.process(this, exchange);
047    }
048
049    @Override
050    public boolean process(Exchange exchange, AsyncCallback callback) {
051        try {
052            if (logger.shouldLog()) {
053                String msg = expression.evaluate(exchange, String.class);
054                logger.doLog(msg);
055            }
056        } catch (Exception e) {
057            exchange.setException(e);
058        } finally {
059            // callback must be invoked
060            callback.done(true);
061        }
062        return true;
063    }
064
065    @Override
066    public String toString() {
067        return "Log(" + logger.getLog().getName() + ")[" + expression + "]";
068    }
069
070    public String getTraceLabel() {
071        return "log[" + expression + "]";
072    }
073
074    public String getId() {
075        return id;
076    }
077
078    public void setId(String id) {
079        this.id = id;
080    }
081
082    public Expression getExpression() {
083        return expression;
084    }
085
086    public CamelLogger getLogger() {
087        return logger;
088    }
089
090    @Override
091    protected void doStart() throws Exception {
092        // noop
093    }
094
095    @Override
096    protected void doStop() throws Exception {
097        // noop
098    }
099}