http://www.eclipse.org/platform: Common Eclipse Runtime (Eclipse Foundation) 
Copyright (c) 2000, 2009 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation

/*******************************************************************************
 * Copyright (c) 2000, 2009 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.core.runtime;


Assert 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.


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 be catching them
specifically).


This class can be used without OSGi running.


This class is not intended to be instantiated or sub-classed by clients.



Since:org.eclipse.equinox.common 3.2
@noinstantiateThis class is not intended to be instantiated by clients.
/**
 * <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 be catching them
 * specifically).
 * </p><p>
 * This class can be used without OSGi running.
 * </p><p>
 * This class is not intended to be instantiated or sub-classed by clients.
 * </p>
 * @since org.eclipse.equinox.common 3.2
 * @noinstantiate This class is not intended to be instantiated by clients.
 */
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 true, an IllegalArgumentException
is thrown.

Params:
  • expression – the outcome of the check
Throws:
Returns:true if the check passes (does not return
   if the check fails)
/** Asserts that an argument is legal. If the given boolean is
	 * not <code>true</code>, an <code>IllegalArgumentException</code>
	 * is thrown.
	 *
	 * @param expression the outcome 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 true, an IllegalArgumentException
is thrown.
The given message is included in that exception, to aid debugging.

Params:
  • expression – the outcome of the check
  • message – the message to include in the exception
Throws:
Returns:true if the check passes (does not return
   if the check fails)
/** 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 outcome 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 null. If this
is not the case, some kind of unchecked exception is thrown.

Params:
  • object – the value to test
/** 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
	 */
	public static void isNotNull(Object object) {
		isNotNull(object, ""); //$NON-NLS-1$
	}

	
Asserts that the given object is not null. If this
is not the case, some kind of unchecked exception is thrown.
The given message is included in that exception, to aid debugging.

Params:
  • object – the value to test
  • message – the message to include in the exception
/** 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
	 */
	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 true. If this
is not the case, some kind of unchecked exception is thrown.

Params:
  • expression – the outcome of the check
Returns:true if the check passes (does not return
   if the check fails)
/** 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 outcome 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 true. If this
is not the case, some kind of unchecked exception is thrown.
The given message is included in that exception, to aid debugging.

Params:
  • expression – the outcome of the check
  • message – the message to include in the exception
Returns:true if the check passes (does not return
   if the check fails)
/** 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 outcome 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;
	}
}