Overview | Package | Class | Use | Tree | Deprecated | Index | Help
| Eclipse Platform Release 3.0
PREV CLASS NEXT CLASS | FRAMES NO FRAMES
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD

## org.eclipse.jface.util
Class Assert

    java.lang.Object
      org.eclipse.jface.util.Assert

public final class Assert
extends Object

`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.

Method Summary
`static boolean` | `isLegal(boolean expression)` Asserts that an argument is legal.
`static boolean` | `isLegal(boolean expression, String message)` Asserts that an argument is legal.
`static void` | `isNotNull(Object object)` Asserts that the given object is not `null`.
`static void` | `isNotNull(Object object, String message)` Asserts that the given object is not `null`.
`static boolean` | `isTrue(boolean expression)` Asserts that the given boolean is `true`.
`static boolean` | `isTrue(boolean expression, String message)` Asserts that the given boolean is `true`.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Method Detail

### isLegal

    public static boolean isLegal(boolean expression)

  Asserts that an argument is legal. If the given boolean is not `true`, an `IllegalArgumentException` is thrown.

  Parameters:
    `expression` - the outcome of the check
  Returns:
    `true` if the check passes (does not return if the check fails)
  Throws:
    `IllegalArgumentException` - if the legality test failed

### isLegal

    public static boolean isLegal(boolean expression,
                                  String message)

  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.

  Parameters:
    `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)
  Throws:
    `IllegalArgumentException` - if the legality test failed

### isNotNull

    public static void isNotNull(Object object)

  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.

  Parameters:
    `object` - the value to test
  Throws:
    `Throwable` - an unspecified unchecked exception if the object is `null`

### isNotNull

    public static void isNotNull(Object object,
                                 String message)

  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.

  Parameters:
    `object` - the value to test
    `message` - the message to include in the exception
  Throws:
    `Throwable` - an unspecified unchecked exception if the object is `null`

### isTrue

    public static boolean isTrue(boolean expression)

  Asserts that the given boolean is `true`. If this is not the case, some kind of unchecked exception is thrown.

  Parameters:
    `expression` - the outcome of the check
  Returns:
    `true` if the check passes (does not return if the check fails)

### isTrue

    public static boolean isTrue(boolean expression,
                                 String message)

  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.

  Parameters:
    `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)

Overview | Package | Class | Use | Tree | Deprecated | Index | Help
| Eclipse Platform Release 3.0
PREV CLASS NEXT CLASS | FRAMES NO FRAMES
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD

Guidelines for using Eclipse APIs.

Copyright (c) IBM Corp. and others 2000, 2004. All rights reserved.