patterntesting.java.runtime
Aspect AbstractNullPointerTrap

java.lang.Object
  patterntesting.java.runtime.AbstractNullPointerTrap

Direct Known Subclasses:

NullPointerTrap

public abstract aspect AbstractNullPointerTrap
extends java.lang.Object

Advice Detail

before

before(): invalidNullParameter..

If a (null) parameter is detected something is wrong with the application code

Advises:

patterntesting.java.runtime.AbstractNullPointerTrapTest.acceptNoNullArg

afterReturning

afterReturning(java.lang.Object): nonVoidMethods..

A 'null' as return value is often an indication that something is wrong (otherwise an exception should be thrown)

Advises:

patterntesting.java.runtime.AbstractNullPointerTrapTest.getUnallowedNullString

Pointcut Detail

applicationCode()

Specify what the application code is that should be subject to the pattern test.
Ex: pointcut applicationCode(): within(patterntesting.sample.*)

nullArgsAllowed()

Specify which code is allowed to have null parameters.

mayReturnNull()

Specify which methods may return null. Some methods (like find methods or getters) may return a null value.

invalidNullParameter()

Addresses all methods (or constructors) with at least one argument with should not be given as null parameter

What is the difference to the AbstractNullTest aspect? In the AbstractNullTest aspect we log only if a null value is given to a method. The NullPointerTrap here is much stricter: it requires that

• no null value is given
• null as return value is forbidden
• if one of this requirements are hurt an AssertionExecption is thrown.

As in AbstractNullTest you can define exceptions from these strict rules by defining the abstract pointcuts applicationCode, nullArgsAllowed and mayReturnNull. This aspect is intended more for finding bugs in the test phase whereas AbstractNullTest can be also used during production because it logs only the problematic calls with a null parameter.

Since:

11.12.2007

See Also:

AbstractNullTestTest

Pointcut Summary
public	applicationCode() Specify what the application code is that should be subject to the pattern test.
public	nullArgsAllowed() Specify which code is allowed to have null parameters.
public	mayReturnNull() Specify which methods may return null.
(package private)	invalidNullParameter() Addresses all methods (or constructors) with at least one argument with should not be given as null parameter

Advice Summary

before(): invalidNullParameter..
If a (null) parameter is detected something is wrong with the application code

Advises:

patterntesting.java.runtime.AbstractNullPointerTrapTest.acceptNoNullArg

afterReturning(java.lang.Object): nonVoidMethods..
A 'null' as return value is often an indication that something is wrong (otherwise an exception should be thrown)

Advises:

patterntesting.java.runtime.AbstractNullPointerTrapTest.getUnallowedNullString

Constructor Summary

AbstractNullPointerTrap()

Method Summary

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AbstractNullPointerTrap

public AbstractNullPointerTrap()