/*
* Copyright (C) 2010 Brockmann Consult GmbH (info@brockmann-consult.de)
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 3 of the License, or (at your option)
* any later version.
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, see http://www.gnu.org/licenses/
*/
package com.bc.ceres.core;
/**
* <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><p>
* This class is not intended to be instantiated or sub-classed by clients.
* </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)
* @throws IllegalArgumentException if the legality test failed
*/
public static boolean argument(boolean expression) {
return argument(expression, "Assert.argument(false) called"); //$NON-NLS-1$
}
/**
* 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)
* @throws IllegalArgumentException if the legality test failed
*/
public static boolean argument(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
* @throws NullPointerException if the object is <code>null</code>
*/
public static void notNull(Object object) {
notNull(object, "Assert.notNull(null) called"); //$NON-NLS-1$
}
/**
* 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
* @throws NullPointerException if the object is <code>null</code>
*/
public static void notNull(Object object, String message) {
if (object == null) {
throw new NullPointerException(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)
* @throws IllegalStateException if the given boolean is <code>false</code>
*/
public static boolean state(boolean expression) {
return state(expression, "Assert.state(false) called"); //$NON-NLS-1$
}
/** 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)
* @throws IllegalStateException if the given boolean is <code>false</code>
*/
public static boolean state(boolean expression, String message) {
if (!expression) {
throw new IllegalStateException(message); //$NON-NLS-1$
}
return expression;
}
}