Java Platform, Standard Edition or Java SE (formerly known up to version 5.0 as Java 2 Platform, Standard Edition or J2SE), is a collection of Java programming language APIs useful to many Java platform programs. The Java Platform, Enterprise Edition includes all of the classes in the Java SE, plus a number which are more useful to programs running on servers than on workstations. The Java Platform is the name for a computing environment, or platform, from Sun Microsystems which can run applications developed using the Java programming language and set of development tools. ... Java Micro Edition (Java ME or as it used to be referred to J2ME), is a runtime and collection of Java APIs for the development of software for resource contrained devices such as PDAs, cell phones and other consumer appliances. ... Java 2 Platform, Enterprise Edition or Java EE (formerly also J2EE) is a programming platform — part of the Java platform — for developing and running distributed multi-tier architecture applications, based largely on modular components running on an application server. ... Java is an object-oriented programming language developed by James Gosling and colleagues at Sun Microsystems in the early 1990s. ... API may refer to: In computing, application programming interface In petroleum industry, American Petroleum Institute In education, Academic Performance Index This page concerning a three-letter acronym or abbreviation is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... The Java Platform is the name for a computing environment, or platform, from Sun Microsystems which can run applications developed using the Java programming language and set of development tools. ... Java 2 Platform, Enterprise Edition or Java EE (formerly also J2EE) is a programming platform — part of the Java platform — for developing and running distributed multi-tier architecture applications, based largely on modular components running on an application server. ... In object-oriented programming, classes are used to group related variables and functions. ... In computing, a server is a software application that carries out some task (i. ... A computer workstation, often colloquially referred to as workstation, is a high-end general-purpose microcomputer designed to be used by one person at a time and which offers higher performance than normally found in a personal computer, especially with respect to graphics, processing power and the ability to carry...

Starting with the J2SE 1.4 version (Merlin), the Java SE platform has been developed under the Java Community Process. JSR 59 was the umbrella specification for J2SE 1.4 and JSR 176 specified J2SE 5.0 (Tiger). As of 2006, Java SE 6 (Mustang) is being developed under JSR 270. The Java Community Process or JCP, established in 1995, is a formalized process which allows interested parties to be involved in the definition of future versions and features of the Java platform. ... 2006 is a common year starting on Sunday of the Gregorian calendar. ...

The following are descriptions of some of the primary Java SE packages. For a complete list of packages see the J2SE 5.0 API Javadocs.

General purpose packages

java.lang

The Java package java.lang contains fundamental classes and interfaces closely tied to the language and runtime system. This includes the root classes that form the class hierarchy, types tied to the language definition, basic exceptions, math functions, threading, security functions, as well as some information on the underlying native system. lkfnfj cdac ... In computer science, run time (with a space, though often its spelled without one) describes the operation of a computer program, the duration of its execution, from beginning to termination (compare compile time). ... As in taxonomy, the classifications of species, a class hiearchy in computer science is a classification of object types, denoting objects as the instantiations of classes (class is like a blueprint, the object is what is built from that blueprint) inter-relating the various classes by relationships such as inherits... Exception handling is a programming language construct or computer hardware mechanism designed to handle runtime errors or other problems (exceptions) which occur during the execution of a computer program. ... A thread in computer science is short for a thread of execution. ...

The main classes in java.lang are:

• Object – the class that is the root of every class hierarchy.
• Enum – the base class for enumeration classes (as of J2SE 5.0).
• Class – the class that is the root of the Java reflection system.
• Throwable – the class that is the base class of the exception class hierarchy.
• Error, Exception, and RuntimeException – the base classes for each exception type.
• Thread – the class that allows operations on threads.
• String – the class for strings and string literals.
• StringBuffer and StringBuilder – classes for performing string manipulation (StringBuilder as of J2SE 5.0).
• Comparable – the interface that allows generic comparison and ordering of objects (as of J2SE 1.2).
• Iterable – the interface that allows generic iteration using the enhanced for loop (as of J2SE 5.0).
• ClassLoader, Process, Runtime,SecurityManager, and System – classes that provide "system operations" that manage the dynamic loading of classes, creation of external processes, host environment inquiries such as the time of day, and enforcement of security policies.
• Math and StrictMath – classes that provide basic math functions such as sine, cosine, and square root (StrictMath as of J2SE 1.3).
• The primitive wrapper classes that encapsulate primitive types as objects.
• The basic exception classes thrown for language-level and other common exceptions.

Classes in java.lang are automatically imported into every source file. In computer science, reflection (or computational reflection) is the ability of a program to observe and possibly modify its structure and behavior. ... In computer programming and some branches of mathematics, strings are sequences of various simple objects. ... In various branches of mathematics and computer science, strings are sequences of various simple objects (symbols, tokens, characters, etc. ... The StringBuffer class is one of two core string classes in the Java programming language. ... In computer science and in computer programming, statements in pseudocode or in a program are normally obeyed one after the other in the order in which they are written (sequential flow of control). ... Illustration of an application which may use libvorbisfile. ... In computing, a process is a running instance of a program, including all variables and other state. ... A security policy is a plan of action for tackling security issues, or a set of regulations for maintaining a certain level of security. ... In mathematics, the trigonometric functions are functions of an angle, important when studying triangles and modeling periodic phenomena. ... In mathematics, the trigonometric functions are functions of an angle, important when studying triangles and modeling periodic phenomena. ... In mathematics, the principal square root of a non-negative real number is denoted and represents the non-negative real number whose square (the result of multiplying the number by itself) is For example, since This example suggests how square roots can arise when solving quadratic equations such as or... In the Java programming language, a primitive wrapper class is one of eight classes provided in the java. ... In computer science, the principle of information hiding is the hiding of design decisions in a computer program that are most likely to change, thus protecting the program if the design decision is changed. ... In computer science, primitive types, as distinct from composite types - are datatypes provided by a programming language as basic building blocks. ... In strictly mathematical branches of computer science the term object is used in a purely mathematical sense to refer to any thing. While this interpretation is useful in the discussion of abstract theory, it is not concrete enough to serve as a primitive datatype in the discussion of more concrete... Source code (commonly just source or code) is any series of statements written in some human-readable computer programming language. ...

java.lang.ref

The java.lang.ref package provides more flexible types of references than are otherwise available, permitting limited interaction between the application and the Java Virtual Machine (JVM) garbage collector. It is an important package, central enough to the language for the language designers to give it a name that starts with "java.lang", but it is somewhat special-purpose and not used by a lot of developers. This package was added in J2SE 1.2. This article discusses a general notion of reference in computing. ... A Java Virtual Machine or JVM, originally invented by Sun Microsystems [1], is a virtual machine that runs Java byte code. ... In computer science, garbage collection (also known as GC) is a form of automatic memory management. ...

Java has a more expressive system of reference than most other garbage-collected programming languages, which allows for special behavior for garbage collection. A normal reference in Java is known as a strong reference. The java.lang.ref package defines three other types of references—soft, weak, and phantom references. Each type of reference is designed for a specific use. Computer code (HTML with JavaScript) in a tool that uses syntax highlighting (colors) to help the developer see the purpose of each piece of code. ... In computer programming, a weak reference is a reference that does not protect the referent object from collection by a garbage collector. ...

A SoftReference can be used to implement a cache. An object that is not reachable by a strong reference (that is, not strongly reachable), but is referenced by a soft reference is called softly reachable. A softly reachable object may be garbage collected at the discretion of the garbage collector. This generally means that softly reachable objects will only be garbage collected when free memory is low, but again, it is at the discretion of the garbage collector. Semantically, a soft reference means "keep this object unless the memory is needed." Look up cache in Wiktionary, the free dictionary. ...

A WeakReference is used to implement weak maps. An object that is not strongly or softly reachable, but is referenced by a weak reference is called weakly reachable. A weakly reachable object will be garbage collected during the next collection cycle. This behavior is used in the class java.util.WeakHashMap. A weak map allows the programmer to put key/value pairs in the map and not worry about the objects taking up memory when the key is no longer reachable anywhere else. Another possible application of weak references is the string intern pool. Semantically, a weak reference means "get rid of this object when nothing else references it." In computer science, unreachable memory is a block of memory allocated dynamically where the program that allocated the memory no longer has any reachable pointer that refers to it. ... In some modern programming languages, including Java and C#, the string intern pool is a data structure managed internally by the platform or virtual machine to facilitate efficient implementation of certain string processing tasks. ...

A PhantomReference is used to reference objects that have been marked for garbage collection but have not yet been finalized. An object that is not strongly, softly or weakly reachable, but is referenced by a phantom reference is called phantom reachable. This allows for more flexible cleanup than is possible with the finalization mechanism alone. Semantically, a phantom reference means "this object is no longer needed and is to be finalized in preparation for being collected." In object-oriented programming languages that use automatic garbage collection, a finalizer is a special method that is executed when an object is garbage collected. ...

Each of these reference types extends the Reference class which provides the get() method to return a strong reference to the referent object (or null if the reference has been cleared), and the clear() method to clear the reference. Used mainly in object-oriented programming, the term method refers to a piece of code that is exclusively associated either with a class (called class methods or static methods) or with an object (called instance methods). ...

The java.lang.ref also defines the class ReferenceQueue, which can be used in each of the applications discussed above to keep track of objects that have changed reference type.

java.lang.reflect

Reflection is a constituent of the Java API which enables Java code to examine and "reflect" upon Java components at runtime and to use the reflected members. Classes in this package, along with java.lang.Class and java.lang.Package accommodate applications such as debuggers, interpreters, object inspectors, class browsers, and services such as object serialization and JavaBeans that need access to either the public members of a target object (based on its runtime class) or the members declared by a given class. This package was added in JDK 1.1. In computer science, reflection (or computational reflection) is the ability of a program to observe and possibly modify its structure and behavior. ... Java is an object-oriented programming language developed by James Gosling and colleagues at Sun Microsystems in the early 1990s. ... A debugger is a computer program that is used to debug (and sometimes test or optimize) other programs which might be running on the same computer (host computer) as the debugger is running, or running on a second remote computer which might be a similar machine, a dissimilar computer, or... An interpreter is a computer program that executes other programs. ... A class browser is a feature of an integrated development environment that allows the programmer to browse, navigate, or visualize the structure of object-oriented programming code. ... // General characteristics In an older computer science context serialization means to force one-at-a-time access for the purposes of concurrency control. ... The Enterprise Java Beans specification is one of the several Java APIs in the Java 2 Platform, Enterprise Edition. ...

Reflection is used to instantiate classes and invoke methods using their names, a concept that allows for dynamic programming. Classes, interfaces, methods, fields, and constructors can all be discovered and used at runtime. Reflection is supported by metadata that the JVM has about the program. There are two basic techniques involved in reflection: In computer science, data that has several parts can be divided into fields. ... Constructor is possibly one of a number of things: a model or a plan for contruction of something, for example a blueprint a term used in object oriented programming, see: object lifetime This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same... Metadata (Greek: meta- + Latin: data information), literally data about data, is information that describes another set of data. ...

1. Discovery involves taking an object or class and discovering the members, superclasses, implemented interfaces, and then possibly using the discovered elements.
2. Use by name involves starting with the symbolic name of an element and using the named element.

Discovery

Discovery typically starts with an object and calling the Object.getClass() method to get the object's Class. The Class object has several methods for discovering the contents of the class, for example:

• getMethods() – returns an array of Method objects representing all the public methods of the class or interface
• getConstructors() – returns an array of Constructor objects representing all the public constructors of the class
• getFields() – returns an array of Field objects representing all the public fields of the class or interface
• getClasses() – returns an array of Class objects representing all the public classes and interfaces that are members (e.g. inner classes) of the class or interface
• getSuperclass() – return the Class object representing the superclass of the class or interface (null is returned for interfaces)
• getInterfaces() – returns an array of Class objects representing all the interfaces that are implemented by the class or interface

An inner class is a class defined entirely within another class. ...

Use by name

The Class object can be obtained either through discovery, by using the class literal (e.g. MyClass.class) or by using the name of the class (e.g. Class.forName("mypackage.MyClass")). With a Class object, member Method, Constructor, or Field objects can be obtained using the symbolic name of the member. For example:

• getMethod("methodName", Class...) – returns the Method object representing the public method with the name "methodName" of the class or interface that accepts the parameters specified by the Class... parameters.
• getConstructor(Class...) – returns the Constructor object representing the public constructor of the class that accepts the parameters specified by the Class... parameters.
• getField("fieldName") – returns the Field object representing the public field with the name "fieldName" of the class or interface.

Method, Constructor, and Field objects can be used to dynamically access the represented member of the class. For example:

• Field.get(Object) – returns an Object containing the value of the field from the instance of the object passed to get(). (If the Field object represents a static field then the Object parameter is ignored and may be null.)
• Method.invoke(Object, Object...) – returns an Object containing the result of invoking the method for the instance of the first Object parameter passed to invoke(). The remaining Object... parameters are passed to the method. (If the Method object represents a static method then the first Object parameter is ignored and may be null.)
• Constructor.newInstance(Object...) – returns the new Object instance from invoking the constructor. The Object... parameters are passed to the constructor. (Note that the parameterless constructor for a class can also be invoked by calling newInstance().)

Used mainly in object-oriented programming, the term method refers to a piece of code that is exclusively associated either with a class (called class methods or static methods) or with an object (called instance methods). ...

Arrays and proxies

The java.lang.reflect package also provides an Array class that contains static methods for creating and manipulating array objects, and since J2SE 1.3, a Proxy class that supports dynamic creation of proxy classes that implement specified interfaces.

The implementation of a Proxy class is provided by a supplied object that implements the InvocationHandler interface. The InvocationHandler's invoke(Object, Method, Object[]) method is called for each method invoked on the proxy object—the first parameter is the proxy object, the second parameter is the Method object representing the method from the interface implemented by the proxy, and the third parameter is the array of parameters passed to the interface method. The invoke() method returns an Object result that contains the result returned to the code that called the proxy interface method.

java.io

The java.io package contains classes that support input and output. The classes in the package are primarily stream-oriented, however, a class for random access files is also provided. The central classes in the package are InputStream and OutputStream which are abstract base classes for reading from and writing to byte streams, respectively. The related classes Reader and Writer are abstract base classes for reading from and writing to character streams, respectively. The package also has a few miscellaneous classes to support interactions with the host file system. Input/output, or I/O, is the collection of interfaces that different functional units (sub-systems) of an information processing system use to communicate with each other, or to the signals (information) sent through those interfaces. ... In computing, the term stream is used in a number of ways, in all cases referring to a succession of data elements made available over time. ... In computer science, random access is the ability to access a random element of a group in equal time. ... A file in a computer system is a stream (sequence) of bits stored as a single unit, typically in a file system on disk or magnetic tape. ... In object-oriented programming, classes are used to group related variables and functions. ... A byte stream is an abstraction used in computer science to describe a particular kind of communication channel between two entities. ... In computing, a file system is a method for storing and organizing computer files and the data they contain to make it easy to find and access them. ...

Streams

The stream classes follow the decorator pattern by extending the base subclass to add features to the stream classes. Subclasses of the base stream classes are typically named for one of the following attributes: In object-oriented programming, a decorator pattern is a design pattern. ...

• the source/destination of the stream data
• the type of data written to/read from the stream
• additional processing or filtering performed on the stream data

The stream subclasses are named using the naming pattern XxxStreamType where Xxx is the name describing the feature and StreamType is one of InputStream, OutputStream, Reader, or Writer. For the martial arts related meaning of Pattern see Tae Kwon Do and Kata (Karate). ...

The following table shows the sources/destinations supported directly by the java.io package:

Source/Destination	Name	Stream types	In/Out	Classes
byte array (byte[])	ByteArray	byte	in, out	ByteArrayInputStream, ByteArrayOutputStream
char array (char[])	CharArray	char	in, out	CharArrayReader, CharArrayWriter
file	File	byte, char	in, out	FileInputStream, FileOutputStream, FileReader, FileWriter
string (StringBuffer)	String	char	in, out	StringReader, StringWriter
thread (Thread)	Piped	byte, char	in, out	PipedInputStream, PipedOutputStream, PipedReader, PipedWriter

Other standard library packages provide stream implementations for other destinations, such as the InputStream returned by the java.net.Socket.getInputStream() method or the Java EE javax.servlet.ServletOutputStream class. A byte is commonly used as a unit of storage measurement in computers, regardless of the type of data being stored. ... In computer programming, an array, also known as a vector or list (for one-dimensional arrays) or a matrix (for two-dimensional arrays), is one of the simplest data structures. ... A file in a computer system is a stream (sequence) of bits stored as a single unit, typically in a file system on disk or magnetic tape. ... In computer programming and some branches of mathematics, strings are sequences of various simple objects. ... The StringBuffer class is one of two core string classes in the Java programming language. ... A thread in computer science is short for a thread of execution. ...

Data type handling and processing or filtering of stream data is accomplished through stream filters. The filter classes all accept another compatible stream object as a parameter to the constructor and decorate the enclosed stream with addional features. Filters are created by extending one of the base filter classes FilterInputStream, FilterOutputStream, FilterReader, or FilterWriter. A filter is a computer program to process a data stream. ...

The Reader and Writer classes are really just byte streams with additional processing performed on the data stream to convert the bytes to characters. They use the default character encoding for the platform, which as of J2SE 5.0 is represented by the Charset returned by the java.nio.charset.Charset.defaultCharset() static method. The InputStreamReader class converts an InputStream to a Reader and the OutputStreamWriter class converts an OutputStream to a Writer. Both these classes have constructors that allow the character encoding to use to be specified—if no encoding is specified then the default encoding for the platform is used. A character encoding consists of a code that pairs a set of characters (representations of graphemes or grapheme-like units, such as might appear in an alphabet or syllabary for the communication of a natural language) with a set of something else, such as numbers or electrical pulses, in order...

The following table shows the other processes and filters supported directly by the java.io package. All of these classes extend the corresponding Filter class.

Operation	Name	Stream types	In/Out	Classes
buffering	Buffered	byte, char	in, out	BufferedInputStream, BufferedOutputStream, BufferedReader, BufferedWriter
"push back" last value read	Pushback	byte, char	in	PushbackInputStream, PushbackReader
read/write primitive types	Data	byte	in, out	DataInputStream, DataOutputStream
object serialization (read/write objects)	Object	byte	in, out	ObjectInputStream, ObjectOutputStream

In computing, a buffer is memory used to temporarily hold output or input data. ... In computer science, primitive types, as distinct from composite types - are datatypes provided by a programming language as basic building blocks. ... See serial publication for the term in publishing In computer science, serialization means to force one-at-a-time access for the purposes of concurrency control, or to encode a data structure as a sequence of bytes. ...

Random access

The RandomAccessFile class supports random access reading and writing of files. The class uses a file pointer that represents a byte-offset within the file for the next read or write operation. The file pointer is moved implicitly by reading or writing and explicitly by calling the seek(long) or skipBytes(int) methods. The current position of the file pointer is returned by the getFilePointer() method. In computer science, random access is the ability to access a random element of a group in equal time. ...

File system

The File class represents a file or directory path in a file system. File objects support the creation, deletion and renaming of files and directories and the manipulation of file attributes such as read-only and last modified timestamp. File objects that represent directories can be used to get a list of all of the contained files and directories. A file in a computer system is a stream (sequence) of bits stored as a single unit, typically in a file system on disk or magnetic tape. ... This article is about the computing term. ... A path is the general form of a file or directory name, giving a files name and its unique location in a file system. ... In computing, a file system is a method for storing and organizing computer files and the data they contain to make it easy to find and access them. ... A file attribute is a piece of data that describes or is associated with a computer file. ...

The FileDescriptor class is a file descriptor that represents a source or sink (destination) of bytes. Typically this is a file, but can also be a console or network socket. FileDescriptor objects are used to create File streams. They are obtained from File streams and java.net sockets and datagram sockets. The term file descriptor is generally used in POSIX operating systems. ... The console is the text output device for system administration messages, particularly those from the BIOS or boot loader, the kernel, from the init system and from the system logger. ...

java.nio

Main article: New I/O

In J2SE 1.4, the package java.nio (NIO or New I/O) was added to support memory-mapped I/O, facilitating IO operations closer to the underlying hardware with sometimes dramatically better performance. The java.nio package provides support for a number of buffer types. The subpackage java.nio.charset provides support for different character encodings for character data. The subpackage java.nio.channels provides support for channels, which represent connections to entities that are capable of performing I/O operations, such as files and sockets. The java.nio.channels package also provides support for fine-grained locking of files. In computing, New I/O, usually called NIO, is a collection of APIs in Java programming language that offers features for intensive I/O operations. ... For more generic meanings of input/output port, see port (computing). ... Io or io may stand for: In Greek mythology, Io (IPA or ) was the daughter of Inachus, a river god. ... A character encoding consists of a code that pairs a set of characters (representations of graphemes or grapheme-like units, such as might appear in an alphabet or syllabary for the communication of a natural language) with a set of something else, such as numbers or electrical pulses, in order...

java.math

The java.math package supports multiprecision arithmetic (including modular arithmetic operations) and provides multiprecision prime number generators used for cryptographic key generation. The main classes of the package are: java. ...

• BigDecimal – provides arbitrary-precision signed decimal numbers. BigDecimal gives the user control over rounding behavior through RoundingMode.
• BigInteger – provides arbitrary-precision integers. Operations on BigInteger do not overflow or lose precision. In addition to standard arithmetic operations, it provides modular arithmetic, GCD calculation, primality testing, prime number generation, bit manipulation, and other miscellaneous operations.
• MathContext – encapsulate the context settings which describe certain rules for numerical operators.
• RoundingMode – an enumeration that provides eight rounding behaviors.

The term arithmetic overflow or simply overflow has the following meanings. ... Modular arithmetic is a system of arithmetic for integers, where numbers wrap around after they reach a certain value — the modulus. ... In mathematics, the greatest common divisor (gcd), sometimes known as the greatest common factor (gcf) or highest common factor (hcf) of two integers which are not both zero is the largest integer that divides both numbers. ... A primality test is an algorithm for determining whether an input number is prime. ... In mathematics, a prime number (or a prime) is a natural number that has two distinct positive divisors, one and itself. ... This article is about the unit of information; for other uses, see Bit (disambiguation). ...

java.net

The java.net package provides special IO routines for networks, allowing HTTP requests, as well as other common transactions. HTTP (for HyperText Transfer Protocol) is the primary method used to convey information on the World Wide Web. ...

java.text

The java.text package implements parsing routines for strings and supports various human-readable languages and locale-specific parsing.

java.util

Data structures that aggregate objects are the focus of the java.util package. Included in the package is the Collections API, an organized data structure hierarchy influenced heavily by the design patterns considerations. A binary tree, a simple type of branching linked data structure. ... Java is an object-oriented programming language developed primarily by James Gosling and colleagues at Sun Microsystems. ... In software engineering, a design pattern is a general repeatable solution to a commonly-occurring problem in software design. ...

Special purpose packages

java.applet

Main article: Java applet

Created to support Java applet creation, the java.applet package allows applications to be downloaded over a network and run within a guarded sandbox. Security restrictions are easily imposed on the sandbox. A developer, for example, may apply a digital signature to an applet, thereby labeling it as safe. Doing so allows the user to grant the applet permission to perform restricted operations (such as accessing the local hard drive), and removes some or all of the sandbox restrictions. Digital certificates are issued by such agencies as Thawte or Entrust. A Java applet is an applet written in the Java programming language. ... A Java applet is an applet written in the Java programming language. ... Digital signature (or public-key digital signature) is a type of method for authenticating digital information analogous to ordinary physical signatures on paper, but implemented using techniques from the field of public-key cryptography. ... Thawte Consulting is a certificate authority (CA) for X.509 certificates. ... Entrust is a Canadian company, a spinoff of Nortel. ...

java.beans

Main article: JavaBeans

Included in the java.beans package are various classes for developing and manipulating beans, reusable components defined by the JavaBeans architecture. The architecture provides mechanisms for manipulating properties of components and firing events when those properties change. The Enterprise Java Beans specification is one of the several Java APIs in the Java 2 Platform, Enterprise Edition. ... The Enterprise Java Beans specification is one of the several Java APIs in the Java 2 Platform, Enterprise Edition. ...

Most of the APIs in java.beans are intended for use by a bean editing tool, in which beans can be combined, customized and manipulated. One type of bean editor is a GUI designer in an integrated development environment. A graphical user interface (or GUI, sometimes pronounced gooey) is a method of interacting with a computer through a metaphor of direct manipulation of graphical images and widgets in addition to text. ... An integrated development environment (IDE), also known as integrated design environment and integrated debugging environment, is a type of computer software that assists computer programmers to develop software. ...

java.awt

Main article: Abstract Windowing Toolkit

The Abstract Windowing Toolkit contains routines to support basic GUI operations and uses basic windows from the underlying native system. Many independent implementations of the Java API (such as GNU's libgcj) implement everything but AWT, which is not used by most server-side applications. This package also contains the Java2D graphics API. The Abstract Windowing Toolkit (AWT) is Javas platform_independent windowing, graphics, and user_interface widget toolkit. ... The Abstract Windowing Toolkit (AWT) is Javas platform_independent windowing, graphics, and user_interface widget toolkit. ... Gui is short for Guilherme or Guilhermo or an iteration of that, in English it translates to Will. ... In computer networking, the term server-side refers to operations that are performed by the server in a client-server relationship. ... In computing, Java2D is an API for drawing two-dimensional graphics using the Java programming language. ...

java.rmi

Main article: Java Remote Method Invocation

The java.rmi package provides Java remote method invocation to support remote procedure calls between two java applications running in different JVMs. The Java Remote Method Invocation API, or RMI, is a Java application programming interface for performing remote procedural calls. ... The Java Remote Method Invocation API, or RMI, is a Java application programming interface for performing remote procedural calls. ... A remote procedure call (RPC) is a protocol that allows a computer program running on one host to cause code to be executed on another host without the programmer needing to explicitly code for this. ... A Java virtual machine or JVM is a virtual machine that runs Java byte code. ...

java.security

Support for security, including the message digest algorithm, is included in the java.security package.

java.sql

Main article: Java Database Connectivity

An implementation of the JDBC API (used to access SQL databases) is grouped into the java.sql package. Java Database Connectivity, or JDBC, is an API for the Java programming language that defines how a client may access a database. ... Java Database Connectivity, or JDBC, is an API for the Java programming language that defines how a client may access a database. ... SQL (commonly expanded to Structured Query Language - see History for the terms derivation) is the most popular computer language used to create, modify and retrieve data from relational database management systems. ... A database is an organized collection of data. ...

javax.swing

Main article: Swing (Java)

Swing is a collection of routines that build on java.awt to provide a platform independent widget toolkit. Swing uses the 2D drawing routines to render the user interface components instead of relying on the underlying native operating system GUI support. Swing is a GUI toolkit for Java. ... Swing is a GUI toolkit for Java. ... In computer programming, widget toolkits (or GUI toolkits) are sets of basic building elements for graphical user interfaces. ... An operating system is a special computer program that manages the relationship between application software, the wide variety of hardware that makes up a computer system, and the user of the system. ...

Swing is a very rich system in its own right, supporting pluggable looks and feels (PLAFs) so that widgets in the GUI can imitate those from the underlying native system. Design patterns permeate the system, especially a modification of the model-view-controller pattern, which loosens the coupling between function and appearance. One inconsistency is that (as of J2SE 1.3) fonts are drawn by the underlying native system, and not by Java, limiting text portability. Workarounds, such as using bitmap fonts, do exist. In general, layouts are used and keep elements within an aesthetically consistent GUI across platforms. This article or section should include material from Model view controller triad Model-View-Controller (MVC) is a software architecture that separates an applications data model, user interface, and control logic into three distinct components so that modifications to the view component can be made with minimal impact to... In computer science, coupling or dependency is the degree to which each program module relies on each other module. ...

External links

• Java SE Main page
• J2SE 5.0 API Javadocs
• Java SE API documentation
• JSR 270 (Java SE 6)
• JSR 176 (J2SE 5.0)
• JSR 59 (J2SE 1.4)