ApexNullPointerExceptionRule (Retired)

ApexNullPointerExceptionRule identifies Apex operations that dereference null objects and throw NullPointerExceptions. NullPointerExceptions generally indicate underlying problems in your code to address.

Definition

• Source

  • : @AuraEnabled-annotated methods. @InvocableMethod-annotated methods. @NamespaceAccessible-annotated methods. @RemoteAction-annotated methods. Any method returning a PageReference object. public-scoped methods on Visualforce Controllers. global-scoped methods on any class. Messaging.InboundEmailResult handleInboundEmail() methods on implementations of Messaging.InboundEmailHandler. Any method targeted during invocation.

• Sink

  • : Any object dereference is a potential sink because object dereferences are the places where a null pointer exception can be thrown. Example: x.someMethod() |

• Sanitizer

  • : Non-null initialization of variables and null checks before accessing. Examples: String s = 'abcde'; , if (s != null) {.

Interpreting Results

Match any violation message that you receive with this case to understand more about the violation.

Common Case

ApexNullPointerExceptionRule identifies Apex operations with a high likelihood of throwing a NullPointerException

The operation dereferences a null object and throws a NullPointerException. Review your code and add a null check.

Examples

In these examples, Apex Runtime throws a System.NullPointerException at the place where an operation is performed on a null object. The Graph Engine ApexNullPointerException rule preemptively identifies these operations.

public void example1() {
	Object myStr = null;
	System.debug(myStr.toLowerCase());
// throws System.NullPointerException
// since method is invoked on null object.
}

public void example2(String myStr) {
	if (myStr == null) {
		// The following line throws System.NullPointerException, since the conditional confirms
		// that myStr is null when it reaches here.
		System.debug(myStr.toLowerCase());
	}
}

public void example3() {
	Integer i; // Not initialized
	Integer y = i + 2;
// throws System.NullPointerException since
// binary operation is invoked on null object
}

To fix NullPointerException issues, use one of these methods.

• Check that the object is not-null before performing the operation.
• Make sure that all variables are initialized.

Avoid initializing variables to null. If your logic demands initialization to null, make sure to reassign a value to your variable before you invoke an operation on it.