Java Cookbook

Program: Debug

Most of the chapters of this book will end with a “Program” recipe that illustrates some aspect of the material covered in the chapter. Example 1-2 is the source code for the Debug utility mentioned in Section 1.12.

Example 1-2. Debug.java

package com.darwinsys.util;

/** Utilities for debugging
 */
public class Debug {
    /** Static method to see if a given category of debugging is enabled.
     * Enable by setting e.g., -Ddebug.fileio to debug file I/O operations.
     * Use like this:<BR>
     * if (Debug.isEnabled("fileio"))<BR>
     *     System.out.println("Starting to read file " + fileName);
     */
    public static boolean isEnabled(String category) {
        return System.getProperty("debug." + category) != null;
    }

    /** Static method to println a given message if the
     * given category is enabled for debugging.
     */
    public static void println(String category, String msg) {
        if (isEnabled(category))
            System.out.println(msg);
    }
    /** Same thing but for non-String objects (think of the other
     * form as an optimization of this).
     */
    public static void println(String category, Object stuff) {
        println(category, stuff.toString(  ));
    }
}