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 java.util.HashSet;
020import java.util.LinkedHashSet;
021import java.util.Set;
022
023import org.apache.camel.AsyncCallback;
024import org.apache.camel.AsyncProcessor;
025import org.apache.camel.Exchange;
026import org.apache.camel.Expression;
027import org.apache.camel.Traceable;
028import org.apache.camel.spi.IdAware;
029import org.apache.camel.spi.LogListener;
030import org.apache.camel.spi.MaskingFormatter;
031import org.apache.camel.support.ServiceSupport;
032import org.apache.camel.util.AsyncProcessorHelper;
033import org.apache.camel.util.CamelLogger;
034import org.slf4j.Logger;
035import org.slf4j.LoggerFactory;
036
037/**
038 * A processor which evaluates an {@link Expression} and logs it.
039 *
040 * @version 
041 */
042public class LogProcessor extends ServiceSupport implements AsyncProcessor, Traceable, IdAware {
043
044    private static final Logger LOG = LoggerFactory.getLogger(LogProcessor.class);
045    private String id;
046    private final Expression expression;
047    private final CamelLogger logger;
048    private final MaskingFormatter formatter;
049    private final Set<LogListener> listeners;
050
051    public LogProcessor(Expression expression, CamelLogger logger, MaskingFormatter formatter, Set<LogListener> listeners) {
052        this.expression = expression;
053        this.logger = logger;
054        this.formatter = formatter;
055        this.listeners = listeners;
056    }
057
058    public void process(Exchange exchange) throws Exception {
059        AsyncProcessorHelper.process(this, exchange);
060    }
061
062    @Override
063    public boolean process(Exchange exchange, AsyncCallback callback) {
064        try {
065            if (logger.shouldLog()) {
066                String msg = expression.evaluate(exchange, String.class);
067                if (formatter != null) {
068                    msg = formatter.format(msg);
069                }
070                msg = fireListeners(exchange, msg);
071                logger.doLog(msg);
072            }
073        } catch (Exception e) {
074            exchange.setException(e);
075        } finally {
076            // callback must be invoked
077            callback.done(true);
078        }
079        return true;
080    }
081
082    private String fireListeners(Exchange exchange, String message) {
083        if (listeners == null) {
084            return message;
085        }
086        for (LogListener listener : listeners) {
087            if (listener == null) {
088                continue;
089            }
090            try {
091                String output = listener.onLog(exchange, logger, message);
092                message = output != null ? output : message;
093            } catch (Throwable t) {
094                LOG.warn("Ignoring an exception thrown by {}: {}", listener.getClass().getName(), t.getMessage());
095                if (LOG.isDebugEnabled()) {
096                    LOG.debug("", t);
097                }
098            }
099        }
100        return message;
101    }
102
103    @Override
104    public String toString() {
105        return "Log(" + logger.getLog().getName() + ")[" + expression + "]";
106    }
107
108    public String getTraceLabel() {
109        return "log[" + expression + "]";
110    }
111
112    public String getId() {
113        return id;
114    }
115
116    public void setId(String id) {
117        this.id = id;
118    }
119
120    public Expression getExpression() {
121        return expression;
122    }
123
124    public CamelLogger getLogger() {
125        return logger;
126    }
127
128    public MaskingFormatter getLogFormatter() {
129        return formatter;
130    }
131
132    @Override
133    protected void doStart() throws Exception {
134        // noop
135    }
136
137    @Override
138    protected void doStop() throws Exception {
139        // noop
140    }
141}