Package java8.util

Provides the JEP 269: Convenience Factory Methods for Collections.

See: Description

Class Summary

Class	Description
Lists2	A place for the new Java 9 JEP 269 "Immutable List Static Factory Methods" in the List interface.
Maps2	A place for the new Java 9 JEP 269 "Immutable Map Static Factory Methods" in the Map interface.
Sets2	A place for the new Java 9 JEP 269 "Immutable Set Static Factory Methods" in the Set interface.

Package java8.util Description

Provides the JEP 269: Convenience Factory Methods for Collections.

Value-based Classes

Some classes, such as java8.util.Optional, are value-based. Instances of a value-based class:

• are final and immutable (though may contain references to mutable objects);
• have implementations of equals, hashCode, and toString which are computed solely from the instance's state and not from its identity or the state of any other object or variable;
• make no use of identity-sensitive operations such as reference equality (==) between instances, identity hash code of instances, or synchronization on an instances's intrinsic lock;
• are considered equal solely based on equals(), not based on reference equality (==);
• do not have accessible constructors, but are instead instantiated through factory methods which make no committment as to the identity of returned instances;
• are freely substitutable when equal, meaning that interchanging any two instances x and y that are equal according to equals() in any computation or method invocation should produce no visible change in behavior.

A program may produce unpredictable results if it attempts to distinguish two references to equal values of a value-based class, whether directly via reference equality or indirectly via an appeal to synchronization, identity hashing, serialization, or any other identity-sensitive mechanism. Use of such identity-sensitive operations on instances of value-based classes may have unpredictable effects and should be avoided.

Since:

9