Logger.java

import java.io.PrintStream;

/**
 * @formatter:off
 * @author Matthew A. Johnston [warmwaffles@gmail.com]
 */
public class Logger {
    public static final int NONE  = 0;
    public static final int ERROR = 1;
    public static final int WARN  = 2;
    public static final int INFO  = 3;
    public static final int DEBUG = 4;

    private static PrintStream out  = System.out;
    private static int currentLevel = INFO;

    /**
     * Sets the logger level.
     *
     * @param level
     */
    public static void setLevel(int level) {
        if (level >= NONE && level <= DEBUG) {
            currentLevel = level;
        }
    }

    /**
     * Does not follow the logger levels. It simply outputs to the console
     * regardless.
     *
     * @param message
     * @param args
     */
    public static void log(String message, Object... args) {
        printf("LOG", message, args);
    }

    /**
     * Log an info message. If no formatting is desired, don't pass extra
     * arguments.
     *
     * @param message
     * @param args
     */
    public static void info(String message, Object... args) {
        if (currentLevel >= INFO) {
            printf("INFO", message, args);
        }
    }

    /**
     * Log an error message. If no formatting is desired, don't pass extra
     * arguments.
     *
     * @param message
     * @param args
     */
    public static void error(String message, Object... args) {
        if (currentLevel >= ERROR) {
            printf("ERROR", message, args);
        }
    }

    /**
     * Log a debug message. If no formatting is desired, don't pass extra
     * arguments.
     *
     * @param message
     * @param args
     */
    public static void debug(String message, Object... args) {
        if (currentLevel >= DEBUG) {
            printf("DEBUG", message, args);
        }
    }

    /**
     * @param message
     * @param args
     */
    public static void warn(String message, Object... args) {
        if (currentLevel >= WARN) {
            printf("WARN", message, args);
        }
    }

    /**
     * @param tag
     * @param format
     * @param args
     */
    private static void printf(String tag, String format, Object... args) {
        if (args.length == 0) {
            out.printf("%s: %s\n", tag, format);
        } else {
            out.printf("%s: %s\n", tag, String.format(format, args));
        }
    }
}