LogAdapter.java

/**
 * Copyright (c) 2010-2016 by the respective copyright holders.
 *
 * 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
 */
package org.openhab.binding.knx.internal.logging;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import tuwien.auto.calimero.log.LogLevel;
import tuwien.auto.calimero.log.LogWriter;

/**
 * An adapter that works as a bridge between the logging API of calimero and slf4j.
 *
 * Calimero (the KNX I/O library used by this binding) has its own and very specific logging framework,
 * which is not compatible with any default logging framework. Thus, this specific adapter is necessary
 * in order to build a bridge between the calimero logging framework and the API of slf4j.
 *
 * All logging events from calimero are written to a single slf4j logger named <code>tuwien.auto.calimero</code>.
 *
 * @author Martin Renner
 * @since 1.5.0
 */
public class LogAdapter extends LogWriter {

    private final static Logger logger = LoggerFactory.getLogger("tuwien.auto.calimero");

    @Override
    public void write(String logService, LogLevel logLevel, String msg) {
        // Simply delegate to the method with exception.
        // org.slf4j.helpers.MessageFormatter will handle this for us.
        write(logService, logLevel, msg, null);
    }

    @Override
    public void write(String logService, LogLevel logLevel, String msg, Throwable t) {
        // Unfortunately, calimero does not use package names for its loggers. So we cannot use "logService" and
        // we have to map all calimero-loggers to a single slf4j logger.

        // slf4j does not offer a "log(level, msg)" api, so we have to dispatch in this rather ugly if-else block.
        if (LogLevel.ALWAYS.equals(logLevel) || LogLevel.FATAL.equals(logLevel) || LogLevel.ERROR.equals(logLevel)) {
            logger.error("{}: {}", logService, msg, t);
        } else if (LogLevel.WARN.equals(logLevel)) {
            logger.warn("{}: {}", logService, msg, t);
        } else if (LogLevel.INFO.equals(logLevel)) {
            logger.info("{}: {}", logService, msg, t);
        } else if (LogLevel.TRACE.equals(logLevel)) {
            logger.debug("{}: {}", logService, msg, t);
        } else {
            logger.info("{}: {}", logService, msg, t);
        }
    }

    @Override
    public void close() {
        // empty
    }

    @Override
    public void flush() {
        // empty
    }
}