org.testng.annotations
Annotation Type Optional

@Retention(value=RUNTIME)
@Target(value=PARAMETER)
public @interface Optional

Specifies that the current parameter is optional. TestNG will pass in a specified default value, or null if none is specified.

Optional Element Summary

java.lang.String

value The default value to pass to this parameter.

value

public abstract java.lang.String value

The default value to pass to this parameter.

The default deserves a bit of explanation. JSR-175 (which defines annotations) says that Java annotation parameters can only be ConstantExpressions, which can be primitive/string literals, but not null.

In this case, we use this string as a substitute for null; in practice, TestNG will pass null to your code, and not the string "null", if you do not specify a default value here in this parameter.

Default:

"null"