Interface (Java) - Bücher neu kaufen

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. An interface in the Java programming language is an abstract type that is used to specify an interface (in the generic sense of the term) that classes must implement. Interfaces are declared using the interface keyword, and may only contain method signatures and constant declarations (variable declarations that are declared to be both static and final). An interface may never contain method definitions. As interfaces are implicitly abstract, they cannot be directly instantiated except when instantiated by a class that implements the said interface. The class must implement all of the methods described in the interface, or be an abstract class. Object references in Java may be specified to be of an interface type; in which case, they must either be null, or be bound to an object that implements the interface. One benefit of using interfaces is that they simulate multiple inheritance. All classes in Java (other than java.lang.Object, the root class of the Java type system) must have exactly one base class; multiple inheritance of classes is not allowed.