【正文】 y further instructions until some other thread calls the notify() method of the same object. Object Once the class is instantiated it bees an object (sometimes referred to as an instance). Overloaded methods Methods are overloaded when there are multiple methods in the same class with the same names but with different parameter lists. Overridden methods Methods in the parent and subclasses with the same name, parameter list, and return type are overridden. Package A package is an entity that groups classes together. The name of the package must reflect the directory structure used to store the classes in your package. The subdirectory begins in any directory indicated by the class path environment variable. PaintEvent Paint events are used internally to ensure serialization of paint operations in the awt event thread. They are not intended to be used like other events. Panel A panel is by far the simplest and most mon of the AWT container classes. Parent class A parent class is a class from which another class is derived. See also Base class. Permanent focus events Permanent focus events indicate that another ponent has gained the focus. Phantom object A phantom object is one that has been finalized, but whose memory has not yet been made available for another object. Phantom reference Phantom references provide a means of delaying the reuse of memory occupied by an object, even if the object itself is finalized. Phantom references are a bit different from soft and weak references. First off, phantom references track memory rather than objects. Secondly, you can never actually get to the object that a phantom reference references. Primitive literal A primitive literal is merely a source code representation of the primitive data types. Primitives Primitives can be a fundamental instruction, operation, or statement. They must be initialized before you attempt to use them (though not necessarily on the same line of code). 12 █ Sun認(rèn)證 Java 2程序員學(xué)習(xí)指南 (Exam 310025) 第二版（影印本） Private members Private members are members of a class that cannot be accessed by any class other than the class in which it is declared. Public access The public keyword placed in front of a class allows all classes from all packages to have access to a class. Public members When a method or variable member is declared public, it means all other classes, regardless of the package that they belong to, can access the member (assuming the class itself is visible). Reference The term reference is shorthand for reference variable. See Reference variable. Reference queue The reference queue gives you a means for determining in bulk which references have changed. Reference queues give the virtual machine a mechanism for telling you that it has collected an object, or more precisely, that the reference has moved to an invalid state. Reference variable A reference variable is an identifier that refers to a primitive type or an object (including an array). A reference variable is a name that points to a location in the puter?s memory where the object is stored. A variable declaration is used to assign a variable name to an object or primitive type. A reference variable is a name that is used in Java to reference an instance of a class. Runtime exceptions A runtime exception is an exception that need not be handled in your program. Usually, runtime exceptions indicate a program bug. These are referred to as unchecked exceptions, since the Java piler does not force the program to handle them. ScrollPane ScrollPane is a container that provides optional scrollbars to gain access to that part of the container that is presently off of the viewable area. The scrollbars may be included as always on or on an asneeded basis. Semantic events Semantic。 Member inner classes。 Inner classes. Class constructors Class constructors are able to call overloaded constructors both in their class and in their superclass. To call another constructor in the same class, you can place a this() in the first line of the body in the calling constructor. Placing this() in any other place will result in a piler error. Class members Class members are variables defined at the class level. These include both instance variables and class (static) variables. Class methods A class method, often referred to as a static method, may be accessed directly from a class, without instantiating the class first. Class variable See Static variable. Collection A collection is an object used to store other objects. Collections are also monly referred to as containers. Two mon examples of collections are Hashtables and Vectors. Collection interface The collection interface defines the public interface that is mon to all collection classes. Collections framework Three elements (interfaces, implementations, and algorithms) create what is known as the collections framework. Command string The mand string contains data about the source or cause of an event. An action event that is the result of a Button being activated contains the Button?s text. An action event that is the result of the ENTER key being pressed in a TextField ponent returns the entered text. Similarly, the text that represents a MenuItem or item in a list ponent is returned when a MenuItem or List is the source of the action event. 4 █ Sun認(rèn)證 Java 2程序員學(xué)習(xí)指南 (Exam 310025) 第二版（影印本） Comparison operators Comparison operators perform a parison on two parameters and return a Boolean value indicating if the parison is true. For example, the parison 24 will result in true while the parison 4==7 will result in false. Components Components are the base class and provide functionality for defining the appearance of the widget, the response (if any) to various events, and, finally, the instructions on how to render itself. A ponent generates a ComponentEvent when