/*******************************************************************************
* Copyright (c) 2000, 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
*******************************************************************************/
package org.eclipse.jst.j2ee.core.internal.plugin;
/**
* <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 {
/* This class is not intended to be instantiated. */
private Assert() {
// not allowed
}
/** 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(message);
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)
throw new AssertionFailedException("null argument:" + message); //$NON-NLS-1$
}
/** Asserts that the given boolean is <code>true</code>. If this
* is not the case, some kind of unchecked exception is thrown.
*
* @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 AssertionFailedException("assertion failed: " + message); //$NON-NLS-1$
return expression;
}
}