/*******************************************************************************
* Copyright (c) 2001, 2005 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
* Jens Lukowski/Innoopract - initial renaming/restructuring
*
*******************************************************************************/
package org.eclipse.wst.sse.core.internal.util;
/**
* <code>Assert</code> is useful for for embedding runtime sanity checks in
* code. The predicate methods all test a condition and throw some type of
* unchecked exception if the condition does not hold.
* <p>
* Assertion failure exceptions, like most runtime exceptions, are thrown when
* something is misbehaving. Assertion failures are invariably unspecified
* behavior; consequently, clients should never rely on these being thrown
* (and certainly should not being catching them specifically).
* </p>
*/
public final class Assert {
/**
* <code>AssertionFailedException</code> is a runtime exception thrown
* by some of the methods in <code>Assert</code>.
* <p>
* This class is not declared public to prevent some misuses; programs
* that catch or otherwise depend on assertion failures are susceptible to
* unexpected breakage when assertions in the code are added or removed.
* </p>
*/
class AssertionFailedException extends RuntimeException {
/**
* Comment for <code>serialVersionUID</code>
*/
private static final long serialVersionUID = 1L;
/**
* Constructs a new exception.
*/
public AssertionFailedException() {
super();
}
/**
* Constructs a new exception with the given message.
*/
public AssertionFailedException(String detail) {
super(detail);
}
}
/**
* Asserts that an argument is legal. If the given boolean is not
* <code>true</code>, an <code>IllegalArgumentException</code> is
* thrown.
*
* @param expression
* the outcode of the check
* @return <code>true</code> if the check passes (does not return if the
* check fails)
* @exception IllegalArgumentException
* if the legality test failed
*/
public static boolean isLegal(boolean expression) {
return isLegal(expression, ""); //$NON-NLS-1$
}
/**
* Asserts that an argument is legal. If the given boolean is not
* <code>true</code>, an <code>IllegalArgumentException</code> is
* thrown. The given message is included in that exception, to aid
* debugging.
*
* @param expression
* the outcode of the check
* @param message
* the message to include in the exception
* @return <code>true</code> if the check passes (does not return if the
* check fails)
* @exception IllegalArgumentException
* if the legality test failed
*/
public static boolean isLegal(boolean expression, String message) {
if (!expression)
throw new IllegalArgumentException();
return expression;
}
/**
* Asserts that the given object is not <code>null</code>. If this is
* not the case, some kind of unchecked exception is thrown.
*
* @param object
* the value to test
* @exception IllegalArgumentException
* if the object is <code>null</code>
*/
public static void isNotNull(Object object) {
isNotNull(object, ""); //$NON-NLS-1$
}
/**
* Asserts that the given object is not <code>null</code>. If this is
* not the case, some kind of unchecked exception is thrown. The given
* message is included in that exception, to aid debugging.
*
* @param object
* the value to test
* @param message
* the message to include in the exception
* @exception IllegalArgumentException
* if the object is <code>null</code>
*/
public static void isNotNull(Object object, String message) {
if (object == null) {
//Logger.log(Logger.ERROR, "null_argument: " + message); //$NON-NLS-1$
throw new Assert().new AssertionFailedException(message);
}
}
/**
* Asserts that the given boolean is <code>true</code>. If this is not
* the case, some kind of unchecked exception is thrown.
*
* @param expression
* the outcode of the check
* @return <code>true</code> if the check passes (does not return if the
* check fails)
*/
public static boolean isTrue(boolean expression) {
return isTrue(expression, ""); //$NON-NLS-1$
}
/**
* Asserts that the given boolean is <code>true</code>. If this is not
* the case, some kind of unchecked exception is thrown. The given message
* is included in that exception, to aid debugging.
*
* @param expression
* the outcode of the check
* @param message
* the message to include in the exception
* @return <code>true</code> if the check passes (does not return if the
* check fails)
*/
public static boolean isTrue(boolean expression, String message) {
if (!expression) {
throw new Assert().new AssertionFailedException(message);
}
return expression;
}
/* This class is not intended to be instantiated. */
private Assert() {
super();
}
}