org.eclipse.jface.util.Assert Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2000, 2009 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.jface.util;
/**
* Assert is useful for for embedding runtime sanity checks
* in code. The static 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 (or not thrown). If you find yourself in the
* position where you need to catch an assertion failure, you have most
* certainly written your program incorrectly.
*
*
* Note that an assert statement is slated to be added to the
* Java language in JDK 1.4, rending this class obsolete.
*
* @deprecated As of 3.3, replaced by {@link org.eclipse.core.runtime.Assert}
*
*/
public final class Assert {
/**
* AssertionFailedException is a runtime exception thrown
* by some of the methods in Assert.
*
* 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.
*
*/
private static class AssertionFailedException extends RuntimeException {
/**
* Generated serial version UID for this class.
*/
private static final long serialVersionUID = 3257852073508024376L;
/**
* Constructs a new exception with the given message.
* @param detail the detail message
*/
public AssertionFailedException(String detail) {
super(detail);
}
}
/* This class is not intended to be instantiated. */
private Assert() {
}
/**
* Asserts that an argument is legal. If the given boolean is
* not true, an IllegalArgumentException
* is thrown.
*
* @param expression the outcome of the check
* @return true if the check passes (does not return
* if the check fails)
* @exception IllegalArgumentException if the legality test failed
*/
public static boolean isLegal(boolean expression) {
// succeed as quickly as possible
if (expression) {
return true;
}
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.
*
* @param expression the outcome of the check
* @param message the message to include in the exception
* @return true 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("assertion failed; " + message); //$NON-NLS-1$
}
return expression;
}
/**
* Asserts that the given object is not null. If this
* is not the case, some kind of unchecked exception is thrown.
*
* As a general rule, parameters passed to API methods must not be
* null unless explicitly allowed in the method's
* specification. Similarly, results returned from API methods are never
* null unless explicitly allowed in the method's
* specification. Implementations are encouraged to make regular use of
* Assert.isNotNull to ensure that null
* parameters are detected as early as possible.
*
*
* @param object the value to test
* @exception AssertionFailedException an unspecified unchecked exception if the object
* is null
*/
public static void isNotNull(Object object) {
// succeed as quickly as possible
if (object != null) {
return;
}
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.
*
* As a general rule, parameters passed to API methods must not be
* null unless explicitly allowed in the method's
* specification. Similarly, results returned from API methods are never
* null unless explicitly allowed in the method's
* specification. Implementations are encouraged to make regular use of
* Assert.isNotNull to ensure that null
* parameters are detected as early as possible.
*
*
* @param object the value to test
* @param message the message to include in the exception
* @exception AssertionFailedException an unspecified unchecked exception if the object
* is null
*/
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.
*
* @param expression the outcome of the check
* @return true if the check passes (does not return
* if the check fails)
*/
public static boolean isTrue(boolean expression) {
// succeed as quickly as possible
if (expression) {
return true;
}
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.
*
* @param expression the outcome of the check
* @param message the message to include in the exception
* @return true 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;
}
}