src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/options/LoggingOption.java

/*
 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package jdk.nashorn.internal.runtime.options;

import java.util.Collections;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.Map.Entry;
import java.util.logging.Level;

/**
 * Class that collects logging options like --log=compiler:finest,fields,recompile:fine into
 * a map form that can be used to instantiate loggers in the Global object on demand
 */
public class LoggingOption extends KeyValueOption {

    /**
     * Logging info. Basically a logger name maps to this,
     * which is a tuple of log level and the "is quiet" flag,
     * which is a special log level used to collect RuntimeEvents
     * only, but not output anything
     */
    public static class LoggerInfo {
        private final Level level;
        private final boolean isQuiet;

        LoggerInfo(final Level level, final boolean isQuiet) {
            this.level = level;
            this.isQuiet = isQuiet;
        }

        /**
         * Get the log level
         * @return log level
         */
        public Level getLevel() {
            return level;
        }

        /**
         * Get the quiet flag
         * @return true if quiet flag is set
         */
        public boolean isQuiet() {
            return isQuiet;
        }
    }

    private final Map<String, LoggerInfo> loggers = new HashMap<>();

    LoggingOption(final String value) {
        super(value);
        initialize(getValues());
    }

    /**
     * Return the logger info collected from this command line option
     *
     * @return map of logger name to logger info
     */
    public Map<String, LoggerInfo> getLoggers() {
        return Collections.unmodifiableMap(loggers);
    }

    /**
     * Initialization function that is called to instantiate the logging system. It takes
     * logger names (keys) and logging labels respectively
     *
     * @param map a map where the key is a logger name and the value a logging level
     * @throws IllegalArgumentException if level or names cannot be parsed
     */
    private void initialize(final Map<String, String> logMap) throws IllegalArgumentException {
        try {
            for (final Entry<String, String> entry : logMap.entrySet()) {
                Level level;
                final String name        = lastPart(entry.getKey());
                final String levelString = entry.getValue().toUpperCase(Locale.ENGLISH);
                final boolean isQuiet;

                if ("".equals(levelString)) {
                    level = Level.INFO;
                    isQuiet = false;
                } else if ("QUIET".equals(levelString)) {
                    level = Level.INFO;
                    isQuiet = true;
                } else {
                    level = Level.parse(levelString);
                    isQuiet = false;
                }

                loggers.put(name, new LoggerInfo(level, isQuiet));
            }
        } catch (final IllegalArgumentException | SecurityException e) {
            throw e;
        }
    }



    private static String lastPart(final String packageName) {
        final String[] parts = packageName.split("\\.");
        if (parts.length == 0) {
            return packageName;
        }
        return parts[parts.length - 1];
    }


}