org.eclipse.gyrex.jobs.internal.externalprocess.AsyncLoggingInputStreamReader.java Source code

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Here is the source code for org.eclipse.gyrex.jobs.internal.externalprocess.AsyncLoggingInputStreamReader.java

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/*******************************************************************************
 * Copyright (c) 2013 AGETO Service GmbH and others.
 * All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html.
 *
 * Contributors:
 *     Gunnar Wagenknecht - initial API and implementation
 *******************************************************************************/
package org.eclipse.gyrex.jobs.internal.externalprocess;

import java.io.InputStream;

import org.apache.commons.io.IOUtils;
import org.apache.commons.io.LineIterator;

import org.slf4j.Logger;

/**
 * Reads and input stream asynchronously into a logger.
 */
public class AsyncLoggingInputStreamReader extends Thread {

    public static enum Level {
        INFO, ERROR
    }

    private final Logger log;
    private final Level level;
    private final InputStream in;
    private volatile boolean closed;
    private volatile String lastLine;

    /**
     * Creates a new instance and starts it right away.
     * 
     * @param name
     * @param in
     * @param log
     * @param level
     * @throws IllegalArgumentException
     */
    public AsyncLoggingInputStreamReader(final String name, final InputStream in, final Logger log,
            final Level level) throws IllegalArgumentException {
        super(name);
        if (in == null)
            throw new IllegalArgumentException("input stream must not be null");
        if (log == null)
            throw new IllegalArgumentException("logger must not be null");
        if (level == null)
            throw new IllegalArgumentException("level must not be null");
        this.in = in;
        this.log = log;
        this.level = level;
        setDaemon(true);
        closed = false;
        start();
    }

    public void close() {
        closed = true;
        IOUtils.closeQuietly(in);
    }

    /**
     * Returns the last read line.
     * 
     * @return the last read line
     */
    public String getLastLine() {
        return lastLine;
    }

    @Override
    public void run() {
        try {
            final LineIterator li = IOUtils.lineIterator(in, null);
            while (!closed && li.hasNext()) {
                final String line = lastLine = li.next();
                switch (level) {
                case ERROR:
                    log.error(line);
                    break;

                case INFO:
                default:
                    log.info(line);
                    break;
                }
            }
        } catch (final Exception | LinkageError | AssertionError e) {
            log.error("Unable to read from stream: {}", e.getMessage(), e);
        } finally {
            IOUtils.closeQuietly(in);
        }
    }
}