Java

A class does not inherit constructors from any of its superclasses.

The Map interface replaces the JDK 1.1 Dictionary class and is used associate keys with values.

A class that is declared without any access modifiers is said to have package or friendly access. This means that the class can only be accessed by other classes and interfaces that are defined within the same package.

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

The Reader/Writer class hierarchy is character-oriented, and the InputStream/OutputStream class hierarchy is byte-oriented.

A catch clause can catch any exception that may be assigned to the Throwable type. This includes the Error and Exception types.

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.

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

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

The peerless components are called light weight components.

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

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

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

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

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

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 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.

Without layout managers, Java programmers are faced with determining how their GUI will be displayed across multiple windowing systems and finding a common sizing and positioning that will work within the constraints imposed by each windowing system.

There are two types of casting, casting between primitive numeric types and casting between object references. Casting between numeric types is used to convert larger values, such as double values, to smaller values, such as byte values. Casting between object references is used to refer to an object by a compatible class, interface, or array type reference.