Debug Utility
/*
* Copyright (c) 1998-2002 Carnegie Mellon University. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY CARNEGIE MELLON UNIVERSITY ``AS IS'' AND
* ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY
* NOR ITS EMPLOYEES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
import java.io.PrintStream;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
public abstract class Debug {
public static final Debug VERBOSE = new Verbose ();
public static final Debug QUIET = new Quiet ();
public static final Debug NONE = new NoDebug ();
public static Debug getDebugLevel (Class cls)
throws NoSuchFieldException {
try {
Field fld = cls.getField ("debug");
if (fld.getType () != Debug.class
|| !Modifier.isStatic (fld.getModifiers ()))
throw new NoSuchFieldException ();
return (Debug) fld.get (null);
} catch (IllegalArgumentException e) {
throw new NoSuchFieldException ();
} catch (IllegalAccessException e) {
throw new NoSuchFieldException ();
} catch (SecurityException e) {
throw new NoSuchFieldException ();
}
}
public static void setDebugLevel (Class cls, Debug level)
throws NoSuchFieldException {
try {
Field fld = cls.getField ("debug");
if (fld.getType () != Debug.class
|| !Modifier.isStatic (fld.getModifiers ()))
throw new NoSuchFieldException ();
fld.set (null, level);
} catch (IllegalArgumentException e) {
throw new NoSuchFieldException ();
} catch (IllegalAccessException e) {
throw new NoSuchFieldException ();
} catch (SecurityException e) {
throw new NoSuchFieldException ();
}
}
public abstract boolean isEnabled ();
public abstract void print (String message);
public abstract void println (String message);
public abstract void print (Object obj);
public abstract void println (Object obj);
public abstract void report (Throwable t);
public abstract void printThreadInfo ();
public abstract void printStackTrace ();
public abstract void assertion (boolean f);
public static class Verbose extends Debug {
protected PrintStream out;
public Verbose () {
this (System.err);
}
public Verbose (PrintStream out) {
this.out = out;
}
public boolean isEnabled () {
return true;
}
public void print (String message) {
out.print (message);
out.flush ();
}
public void println (String message) {
out.println (message);
out.flush ();
}
public void print (Object obj) {
print (obj.toString ());
}
public void println (Object obj) {
println (obj.toString ());
}
public void report (Throwable t) {
t.printStackTrace (out);
out.flush ();
}
public void printThreadInfo () {
ThreadGroup g = Thread.currentThread().getThreadGroup ();
Thread[] t = new Thread[g.activeCount ()];
g.enumerate (t);
out.println ("Active threads in " + g);
for (int i=0; i<t.length; ++i)
out.println (t[i]);
out.flush ();
}
public void printStackTrace () {
try {
throw new Exception ();
} catch (Exception e) {
e.printStackTrace (out);
out.flush ();
}
}
public void assertion (boolean f) {
if (!f)
throw new RuntimeException ("assertion failure");
}
}
public static class Quiet extends Verbose {
public Quiet () {
}
public Quiet (PrintStream out) {
super (out);
}
public boolean isEnabled () {
return false;
}
public void print (String message) {
}
public void println (String message) {
}
public void print (Object message) {
}
public void println (Object message) {
}
public void report (Throwable t) {
t.printStackTrace (out);
out.flush ();
}
public void printThreadInfo () {
}
public void printStackTrace () {
}
public void assertion (boolean f) {
if (!f) {
try {
throw new RuntimeException ("assertion failure");
} catch (RuntimeException e) {
e.printStackTrace (out);
out.flush ();
}
}
}
}
public static class NoDebug extends Debug {
public boolean isEnabled () {
return false;
}
public void print (String message) {
}
public void println (String message) {
}
public void print (Object message) {
}
public void println (Object message) {
}
public void report (Throwable t) {
}
public void printThreadInfo () {
}
public void printStackTrace () {
}
public void assertion (boolean f) {
}
}
}