com.bbn.openmap.util
Class Assert

java.lang.Object
  com.bbn.openmap.util.Assert

public final class Assert
extends java.lang.Object

Assert provides an assertion facility in Java comparable to the assert macros in C/C++. This class was taken from the Java FAQ maintained by Perter Van Der Linden at http://www.afu.com/intro.html , section 17, question 6. Here is the original entry in the FAQ:

 
  11.6 How can I write C/C++ style assertions in Java?
 
  A.  The two classes shown below provide an assertion facility in Java.
      Set Assert.enabled to true to enable the assertions, and to false to
      disable assertions in production code. The AssertionException is not
      meant to be caught--instead, let it print a trace.
 
      With a good optimizing compiler there will be no run time overhead
      for many uses of these assertions when Assert.enabled is set to false.
      However, if the condition in the assertion may have side effects, the
      condition code cannot be optimized away. For example, in the assertion
       
 
 Assert.assertExp(size() <= maxSize, "Maximum size exceeded");
 
 
      the call to size() cannot be optimized away unless the compiler can
      see that the call has no side effects. C and C++ use the preprocessor
      to guarantee that assertions will never cause overhead in production
      code. Without a preprocessor, it seems the best we can do in Java is
      to write
       
 
 Assert.assertExp(Assert.enabled && size() <= maxSize, "Too big");
 
 
      In this case, when Assert.enabled is false, the method call can always
      be optimized away, even if it has side effects.
  
 

Version:

$Revision: 1.4 $, $Date: 2004/10/14 18:06:29 $

Author:

Peter Van Der Linden, Maintained by: Tom Mitchell (tmitchell@bbn.com)

Field Summary

static boolean

enabled Globally enable or disable assertions.

Method Summary

static void	assertExp(boolean b) Assert a condition to be true.
static void	assertExp(boolean b, java.lang.String s) Assert a condition to be true.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

enabled

public static final boolean enabled

Globally enable or disable assertions.

See Also:

Constant Field Values

Method Detail

assertExp

public static final void assertExp(boolean b,
                                   java.lang.String s)

Assert a condition to be true. If it is not true, an exception is thrown.

Parameters:

b - An expression expected to be true

s - Exception string if expression is false

Throws:

AssertionException - if expression is false

assertExp

public static final void assertExp(boolean b)

Assert a condition to be true. If it is not true, an exception is thrown.

Parameters:

b - An expression expected to be true

Throws:

AssertionException - if expression is false