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OBJECTS that subclass the Observable class MAINTAIN a list of observers. When an Observable OBJECT is updated it invokes the update() METHOD of each of its observers to notify the observers that it has changed state. The Observer interface is implemented by objects that observe Observable objects.

Objects that subclass the Observable class maintain a list of observers. When an Observable object is updated it invokes the update() method of each of its observers to notify the observers that it has changed state. The Observer interface is implemented by objects that observe Observable objects.

With respect to multithreading, synchronization is the capability to CONTROL the access of multiple THREADS to shared RESOURCES. Without synchronization, it is possible for one thread to MODIFY a shared object while another thread is in the process of using or updating that object's value. This often causes dirty data and leads to SIGNIFICANT errors.

With respect to multithreading, synchronization is the capability to control the access of multiple threads to shared resources. Without synchronization, it is possible for one thread to modify a shared object while another thread is in the process of using or updating that object's value. This often causes dirty data and leads to significant errors.

Synchronized methods are methods that are used to CONTROL ACCESS to an object. A thread only EXECUTES a synchronized method after it has acquired the lock for the method's object or class. Synchronized statements are similar to synchronized methods. A synchronized STATEMENT can only be executed after a thread has acquired the lock for the object or class referenced in the synchronized statement.

Synchronized methods are methods that are used to control access to an object. A thread only executes a synchronized method after it has acquired the lock for the method's object or class. Synchronized statements are similar to synchronized methods. A synchronized statement can only be executed after a thread has acquired the lock for the object or class referenced in the synchronized statement.

A thread can enter the waiting state by invoking its sleep() method, by BLOCKING on I/O, by unsuccessfully ATTEMPTING to acquire an OBJECT's lock, or by invoking an object's WAIT() method. It can also enter the waiting state by invoking its (deprecated) suspend() method.

A thread can enter the waiting state by invoking its sleep() method, by blocking on I/O, by unsuccessfully attempting to acquire an object's lock, or by invoking an object's wait() method. It can also enter the waiting state by invoking its (deprecated) suspend() method.

The PREFERRED SIZE of a COMPONENT is the MINIMUM component size that will allow the component to DISPLAY normally.

The preferred size of a component is the minimum component size that will allow the component to display normally.

The stop(), SUSPEND() and RESUME() METHODS have been DEPRECATED in JDK 1.2.

The stop(), suspend() and resume() methods have been deprecated in JDK 1.2.

A TRANSIENT VARIABLE is a variable that MAY not be SERIALIZED.

A transient variable is a variable that may not be serialized.

The PANEL and Applet CLASSES USE the FlowLayout as their default layout.

The Panel and Applet classes use the FlowLayout as their default layout.

YES, a LOCK can be ACQUIRED on a CLASS. This lock is acquired on the class's Class OBJECT.

Yes, a lock can be acquired on a class. This lock is acquired on the class's Class object.

The List INTERFACE provides SUPPORT for ORDERED COLLECTIONS of objects.

The List interface provides support for ordered collections of objects.

The COLLECTIONS API is a set of classes and interfaces that SUPPORT operations on collections of OBJECTS.

The Collections API is a set of classes and interfaces that support operations on collections of objects.

When a THREAD terminates its PROCESSING, it enters the DEAD STATE.

When a thread terminates its processing, it enters the dead state.

The setLayout() method is used to SPECIFY a CONTAINER's layout in Java PROGRAMMING.

The setLayout() method is used to specify a container's layout in Java Programming.

The WINDOW, Frame and Dialog classes USE a border layout as their default layout in JAVA Programming.

The window, Frame and Dialog classes use a border layout as their default layout in Java Programming.

The ITERATOR interface is used to step through the ELEMENTS of a COLLECTION.

The Iterator interface is used to step through the elements of a Collection.

A PROTECTED method may only be accessed by classes or INTERFACES of the same package or by subclasses of the CLASS in which it is declared.

A protected method may only be accessed by classes or interfaces of the same package or by subclasses of the class in which it is declared.

A (non-local) inner class may be declared as public, PROTECTED, PRIVATE, STATIC, FINAL, or abstract.

A (non-local) inner class may be declared as public, protected, private, static, final, or abstract.

The Vector CLASS in JAVA Programming provides the capability to IMPLEMENT a growable ARRAY of objects.

The Vector class in Java Programming provides the capability to implement a growable array of objects.

It uses those low order BYTES of the result that can fit into the SIZE of the type allowed by the OPERATION.

It uses those low order bytes of the result that can fit into the size of the type allowed by the operation.

Wrapped CLASSES are classes that allow PRIMITIVE types to be ACCESSED as objects.

Wrapped classes are classes that allow primitive types to be accessed as objects.

The SIZEOF OPERATOR is not a KEYWORD in JAVA PROGRAMMING.

The sizeof operator is not a keyword in Java Programming.

When a task invokes its yield() METHOD, it RETURNS to the ready STATE. When a task invokes its sleep() method, it returns to the WAITING state.

When a task invokes its yield() method, it returns to the ready state. When a task invokes its sleep() method, it returns to the waiting state.

Unicode requires 16 BITS and ASCII require 7 bits. ALTHOUGH the ASCII character SET uses only 7 bits, it is usually REPRESENTED as 8 bits. UTF-8 represents characters using 8, 16, and 18 bit patterns. UTF-16 uses 16-bit and larger bit patterns.

Unicode requires 16 bits and ASCII require 7 bits. Although the ASCII character set uses only 7 bits, it is usually represented as 8 bits. UTF-8 represents characters using 8, 16, and 18 bit patterns. UTF-16 uses 16-bit and larger bit patterns.

for(;;)-for LOOP; while(TRUE)-ALWAYS true, ETC.

for(;;)-for loop; while(true)-always true, etc.

A NATIVE METHOD is a method that is IMPLEMENTED in a LANGUAGE other than JAVA.

A native method is a method that is implemented in a language other than Java.

The CANVAS, Frame, Panel, and Applet CLASSES SUPPORT PAINTING.

The Canvas, Frame, Panel, and Applet classes support painting.

OBJECT class is the SUPERCLASS for every class in Java Programming.

Object class is the superclass for every class in Java Programming.

The purpose of finalization is to give an UNREACHABLE OBJECT the opportunity to PERFORM any CLEANUP processing before the object is garbage collected.

The purpose of finalization is to give an unreachable object the opportunity to perform any cleanup processing before the object is garbage collected.

An ANONYMOUS class may IMPLEMENT an INTERFACE or extend a SUPERCLASS, but may not be declared to do both.

An anonymous class may implement an interface or extend a superclass, but may not be declared to do both.

After a THREAD is STARTED, via its START() method or that of the Thread CLASS, the JVM INVOKES the thread's run() method when the thread is initially executed.

After a thread is started, via its start() method or that of the Thread class, the JVM invokes the thread's run() method when the thread is initially executed.

The SIMPLETIMEZONE class provides SUPPORT for a Gregorian calendar in JAVA Programming.

The SimpleTimeZone class provides support for a Gregorian calendar in Java Programming.

The GregorianCalendar provides SUPPORT for TRADITIONAL Western CALENDARS in JAVA Programming.

The GregorianCalendar provides support for traditional Western calendars in Java Programming.

The properties class is a subclass of Hashtable that can be read from or written to a stream. It also PROVIDES the capability to specify a SET of DEFAULT values to be USED.

The properties class is a subclass of Hashtable that can be read from or written to a stream. It also provides the capability to specify a set of default values to be used.

VALIDATE(); : Container METHOD is used to cause a container to be laid out and REDISPLAYED in Java Programming.

validate(); : Container method is used to cause a container to be laid out and redisplayed in Java Programming.

The purpose of the System CLASS is to provide ACCESS to system RESOURCES in JAVA Programming.

The purpose of the System class is to provide access to system resources in Java Programming.

The PURPOSE of the RUNTIME class is to PROVIDE ACCESS to the JAVA runtime system in Java Programming.

The purpose of the Runtime class is to provide access to the Java runtime system in Java Programming.

The Locale CLASS is used to tailor PROGRAM output to the CONVENTIONS of a PARTICULAR geographic, political, or cultural region.

The Locale class is used to tailor program output to the conventions of a particular geographic, political, or cultural region.

The finally clause is used to provide the capability to EXECUTE code no MATTER WHETHER or not an EXCEPTION is THROWN or caught.

The finally clause is used to provide the capability to execute code no matter whether or not an exception is thrown or caught.

The WAIT(),notify(), and NOTIFYALL() methods are used to provide an efficient way for THREADS to COMMUNICATE each other in Java Programming.

The wait(),notify(), and notifyAll() methods are used to provide an efficient way for threads to communicate each other in Java Programming.

It must PROVIDE all of the methods in the interface and IDENTIFY the interface in its IMPLEMENTS CLAUSE.

It must provide all of the methods in the interface and identify the interface in its implements clause.

The high-level thread STATES are READY, RUNNING, waiting, and DEAD.

The high-level thread states are ready, running, waiting, and dead.

An ABSTRACT method is a method WHOSE IMPLEMENTATION is deferred to a subclass in JAVA Programming.

An abstract method is a method whose implementation is deferred to a subclass in Java Programming.

An OBJECT's lock is a mechanism that is USED by multiple THREADS to obtain synchronized access to the object. A thread may execute a synchronized method of an object only after it has acquired the object's lock. All OBJECTS and classes have locks. A CLASS's lock is acquired on the class's Class object.

An object's lock is a mechanism that is used by multiple threads to obtain synchronized access to the object. A thread may execute a synchronized method of an object only after it has acquired the object's lock. All objects and classes have locks. A class's lock is acquired on the class's Class object.

A non-STATIC INNER class may have object instances that are ASSOCIATED with instances of the class's OUTER class. A static inner class does not have any object instances.

A non-static inner class may have object instances that are associated with instances of the class's outer class. A static inner class does not have any object instances.

The FRAME class extends Window to define a MAIN APPLICATION window that can have a menu BAR.

The Frame class extends Window to define a main application window that can have a menu bar.

An OBJECT REFERENCE be CAST to an interface reference when the object implements the REFERENCED interface.

An object reference be cast to an interface reference when the object implements the referenced interface.

javax.SWING package. All components in Swing, except JApplet, JDialog, JFrame and JWindow are lightweight components in JAVA PROGRAMMING.

javax.Swing package. All components in Swing, except JApplet, JDialog, JFrame and JWindow are lightweight components in Java Programming.

The FontMetrics CLASS is used to define implementation-specific PROPERTIES, such as ascent and DESCENT, of a FONT OBJECT.

The FontMetrics class is used to define implementation-specific properties, such as ascent and descent, of a Font object.

If a thread ATTEMPTS to execute a synchronized method or synchronized statement and is unable to acquire an OBJECT's lock, it enters the WAITING state until the lock BECOMES available.

If a thread attempts to execute a synchronized method or synchronized statement and is unable to acquire an object's lock, it enters the waiting state until the lock becomes available.

Under preemptive scheduling, the highest priority task executes until it enters the WAITING or dead states or a higher priority task comes into existence. Under time slicing, a task executes for a predefined slice of time and then reenters the POOL of ready tasks. The SCHEDULER then determines which task should execute NEXT, based on priority and other FACTORS.

Under preemptive scheduling, the highest priority task executes until it enters the waiting or dead states or a higher priority task comes into existence. Under time slicing, a task executes for a predefined slice of time and then reenters the pool of ready tasks. The scheduler then determines which task should execute next, based on priority and other factors.