Slf4jAdapter.java

/**
 * Copyright 2011-2012 Akiban Technologies, Inc.
 * 
 * Licensed 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 com.persistit.logging;

import org.slf4j.Logger;

/**
 * Wraps an <code>org.slf4j.Logger</code> instance for Persistit logging. Code
 * to enable default logging through Slf4j is shown here: <code><pre>
 *    Logger log = ... instance of org.slf4j.Logger ...
 *    Persistit.setPersistitLogger(new Slf4jAdapter(logger));
 * </pre></code>
 * 
 * @version 1.1
 */

public class Slf4jAdapter implements PersistitLogger {

    private final Logger _logger;

    /**
     * Constructs a wrapped Slf4j Logger.
     * 
     * @param logger
     *            A <code>Logger</code> to which Persistit log messages will be
     *            directed.
     */
    public Slf4jAdapter(final Logger logger) {
        _logger = logger;
    }

    /**
     * Overrides <code>isLoggable</code> to allow control by the wrapped
     * <code>Logger</code>.
     * 
     * @param level
     *            The <code>level</code>
     */
    @Override
    public boolean isLoggable(final PersistitLevel level) {
        switch (level) {
        case NONE:
            return false;
        case TRACE:
            return _logger.isTraceEnabled();
        case DEBUG:
            return _logger.isDebugEnabled();
        case INFO:
            return _logger.isInfoEnabled();
        case WARNING:
            return _logger.isWarnEnabled();
        case ERROR:
            return _logger.isErrorEnabled();
        default:
            throw new RuntimeException("base switch");
        }
    }

    /**
     * Writes a log message generated by Persistit to the wrapped
     * <code>Logger</code>.
     * 
     * @param level
     *            The <code>PersistitLevel</code>
     * @param message
     *            The message to write to the log.
     */
    @Override
    public void log(final PersistitLevel level, final String message) {
        switch (level) {
        case NONE:
            break;
        case TRACE:
            _logger.trace(message);
            break;
        case DEBUG:
            _logger.debug(message);
            break;
        case INFO:
            _logger.info(message);
            break;
        case WARNING:
            _logger.warn(message);
            break;
        case ERROR:
            _logger.error(message);
            break;
        default:
            throw new RuntimeException("base switch");
        }
    }

    @Override
    public void open() {
        // Nothing to do - the log is created and destroyed by the embedding
        // application
    }

    @Override
    public void close() {
        // Nothing to do - the log is created and destroyed by the embedding
        // application
    }

    @Override
    public void flush() {
        // Nothing to do - log output is managed by the embedding
        // application
    }
}