Java in a Nutshell, 5th Edition

Modifier Summary

As we’ve seen, classes, interfaces, and their members can be declared with one or more modifiers—keywords such as public, static, and final. Table 3-2 lists the Java modifiers, explains what types of Java constructs they can modify, and explains what they do. See also Section 3.1 and Section 3.2.1 earlier in this chapter, as well as Section 2.6.2 in Chapter 2.

Table 3-2. Java modifiers

Modifier	Used on	Meaning
abstract	Class	The class contains unimplemented methods and cannot be instantiated.
	Interface	All interfaces are abstract. The modifier is optional in interface declarations.
abstract	Method	No body is provided for the method; it is provided by a subclass. The signature is followed by a semicolon. The enclosing class must also be abstract.
final	Class	The class cannot be subclassed.
	Method	The method cannot be overridden (and is not subject to dynamic method lookup).
	Field	The field cannot have its value changed. static final fields are compile-time constants.
	Variable	A local variable, method parameter, or exception parameter cannot have its value changed. Useful with local classes.
native	Method	The method is implemented in some platform-dependent way (often in C). No body is provided; the signature is followed by a semicolon.
None (package)	Class	A non-public class is accessible only in its package.
	Interface	A non-public interface is accessible only in its package.
	Member	A member that is not