J

     
Java Virtual Machine

Part of the Java Runtime Environment, the JVM is the program that interprets and executes bytecode in compiled Java class files. The JVM is invoked with the java command and supplies programs for a context in which to run, providing resources such as memory management via garbage collection, network access, and security. The JVM acts as an abstraction of the hardware layer, enabling programs written in Java to run on any platform with a Java Virtual Machine. There are different JVM specifications, including one for smart cards and micro devices.



J2EE

Java 2, Enterprise Edition is a free download, separate from the Standard Edition, that offers APIs for database, advanced networking, server-side, and distributed functionality.



J2ME

Java 2 Micro Edition is required for writing small footprint programs runnable micro devices including smart cards, set-top boxes, and handhelds.



J2SE

Java 2 Standard Edition provides the basic development environment for creating portable, secure, network-ready software applications. When declaring an interface, you may only use the public and abstract modifiers. That is, you cannot declare a static method in an interface.



JAR

A Java ARchive is a file format used to aggregate and compress a number of files into one. Because the jar utility, which is included with the standard SDK, uses the same compression algorithm as .zip files, JARs can be manipulated using Zip utilities.



JDBC

Java Database Connectivity is an API that allows programmers to access tabular data stored in relational and object databases, text files, and spreadsheets. JDBC is included with the J2SE.



JDK

Java Development Kit also referred to as SDK (Software Development Kit).



JFC

Java Foundation Classes. Set of Java class libraries, included with J2SE, that support the building of rich Graphical User Interface applications. The JFC includes AWT (Abstract Window Toolkit), Drag and Drop APIs, Java 2D, Swing, Accessibility APIs, and Internationalization support.



JIT Compiler

A Just In Time compiler takes the bytecodes of a .class file at runtime and compiles them into code native to the machine on which it's running. A JIT compiler therefore replaces the functionality of the Java bytecode interpreter. This happens on-the-fly , method-by-method (hence, "just in time").



JNDI

Java Naming and Directory Interface is a set of APIs that support interaction with directory services such as LDAP.



JNI

Java Native Interface allows code that runs in a JVM to interact with code written in other languages, such as C, C++, and assembly. JNI, which is part of the J2SE, is used by programmers when they cannot or do not wish to write their entire application in Java. This situation would occur when you already have some native code written that you'd like to reuse, or if Java does not support the operation you need to perform.



Java RMI

Java Remote Method Invocation is for use in distributed environments, and allows an object in one virtual machine to call methods on an object in another virtual machine.



Java Runtime Environment

The JRE is a subset of the SDK. It includes the Java HotSpot runtime, client compiler, the Java Plugin, and nearly twenty standard libraries (the core classes). It does not include the compiler, the debugger, or other such tools. The JRE is the minimum runtime required for executing Java applications; if your machine ain't got a JRE, it won't run your Java program. That's why JREs are freely distributable, because developers often need to package one along with their applications. Note that the SDK is not freely distributed by developers.





Java Garage
Java Garage
ISBN: 0321246233
EAN: 2147483647
Year: 2006
Pages: 228
Authors: Eben Hewitt

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