SystemLogger.java

package org.maltparser.core.helper;

import org.apache.log4j.ConsoleAppender;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.log4j.PatternLayout;

/**
 *
 *
 * @author Johan Hall
 */
public class SystemLogger {

    private static SystemLogger uniqueInstance = new SystemLogger();
    private static Logger systemLogger;
    private Level systemVerbosityLevel;
    private ConsoleAppender consoleAppender;

    private SystemLogger() {
        systemLogger = Logger.getLogger("System");
        /*
         * System verbosity (Standard Out)
         */
        consoleAppender = new ConsoleAppender(new PatternLayout("%m"), ConsoleAppender.SYSTEM_ERR);
        consoleAppender.setEncoding("UTF-16");
        systemLogger.addAppender(consoleAppender);
        if (System.getProperty("Malt.verbosity") != null) {
            setSystemVerbosityLevel(System.getProperty("Malt.verbosity").toUpperCase());
        } else {
            setSystemVerbosityLevel("INFO");
        }
    }

    /**
     * Returns a reference to the single instance.
     */
    public static SystemLogger instance() {
        return uniqueInstance;
    }

    /**
     * Returns a reference to the Logger.
     */
    public static Logger logger() {
        return systemLogger;
    }

    /**
     * Returns the system verbosity level
     *
     * @return the system verbosity level
     */
    public Level getSystemVerbosityLevel() {
        return systemVerbosityLevel;
    }

    /**
     * Sets the system verbosity level
     *
     * @param verbosity	a system verbosity level
     */
    public void setSystemVerbosityLevel(String verbosity) {
        this.systemVerbosityLevel = Level.toLevel(verbosity, Level.INFO);
        consoleAppender.setThreshold(systemVerbosityLevel);
        systemLogger.setLevel(systemVerbosityLevel);
    }
}