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Classpath
Classpath is a parameter in the Java Virtual Machine or the Java compiler that specifies the location of user-defined classes and packages. The parameter may be set either on the command-line, or through an environment variable. Overview and architecture Similar to the classic dynamic loading behavior, when executing Java programs, the Java Virtual Machine finds and loads classes lazily (it loads the bytecode of a class only when the class is first used). The classpath tells Java where to look in the filesystem for files defining these classes. The virtual machine searches for and loads classes in this order: # bootstrap classes: the classes that are fundamental to the Java Platform (comprising the public classes of the Java Class Library, and the private classes that are necessary for this library to be functional). # extension classes: packages that are in the ''extension'' directory of the Java Runtime Environment or JDK, jre/lib/ext/ # user-defined packages and libr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java Class Library
The Java Class Library (JCL) is a set of dynamically loadable libraries that Java Virtual Machine (JVM) languages can call at run time. Because the Java Platform is not dependent on a specific operating system, applications cannot rely on any of the platform-native libraries. Instead, the Java Platform provides a comprehensive set of standard class libraries, containing the functions common to modern operating systems. JCL serves three purposes within the JVM: * Like other standard code libraries, they provide the programmer a well-known set of useful facilities, such as container classes and regular expression processing. * The library provides an abstract interface to tasks that would normally depend heavily on the hardware and operating system, such as network access and file access. * Some underlying platforms may not support all of the features a Java application expects. In these cases, the library implementation can either emulate those features or provide a consist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java Platform Module System
The Java Platform Module System specifies a distribution format for collections of Java code and associated resources. It also specifies a repository for storing these collections, or '' modules'', and identifies how they can be discovered, loaded and checked for integrity. It includes features such as namespaces with the aim of fixing some of the shortcomings in the existing JAR format, especially the JAR Hell, which can lead to issues such as classpath and class loading problems. The Java Module System was initially being developed under the Java Community Process as JSR 277 and was scheduled to be released with Java 7. JSR 277 later was put on hold and Project Jigsaw was created to modularize the JDK. This JSR was superseded by JSR 376 (Java Platform Module System). Project Jigsaw was originally intended for Java 7 (2011) but was deferred to Java 8 (2014) as part of Plan B, and again deferred to a Java 9 release in 2017. Java 9 including the Java Module System was released o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Javac
javac (pronounced "java-see") is the primary Java compiler included in the Java Development Kit (JDK) from Oracle Corporation. Martin Odersky implemented the GJ compiler, and his implementation became the basis for javac. The compiler accepts source code conforming to the Java language specification (JLS) and produces Java bytecode conforming to the Java Virtual Machine Specification (JVMS). javac is itself written in Java. The compiler can also be invoked programmatically. History On 13 November 2006, Sun's HotSpot Java virtual machine (JVM) and Java Development Kit (JDK) were made available under the GPL license. Since version 0.95, GNU Classpath, a free implementation of the Java Class Library, supports compiling and running javac using the Classpath runtime — GNU Interpreter for Java (GIJ) — and compiler — GNU Compiler for Java (GCJ) — and also allows one to compile the GNU Classpath class library, tools and examples with javac itself. "This release supp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java Platform
Java is a set of computer software and specifications that provides a software platform for developing application software and deploying it in a cross-platform computing environment. Java is used in a wide variety of computing platforms from embedded devices and mobile phones to enterprise servers and supercomputers. Java applets, which are less common than standalone Java applications, were commonly run in secure, Sandbox (computer security), sandboxed environments to provide many features of native applications through being embedded in HTML pages. Writing in the Java (programming language), Java programming language is the primary way to produce code that will be deployed as Java byte code, byte code in a Java virtual machine (JVM); byte code compilers are also available for other languages, including Ada (programming language), Ada, JavaScript, Kotlin (programming language), Kotlin (Google's preferred Android language), Python (programming language), Python, and Ruby (p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java Runtime Environment
Java is a set of computer software and specifications that provides a software platform for developing application software and deploying it in a cross-platform computing environment. Java is used in a wide variety of computing platforms from embedded devices and mobile phones to enterprise servers and supercomputers. Java applets, which are less common than standalone Java applications, were commonly run in secure, sandboxed environments to provide many features of native applications through being embedded in HTML pages. Writing in the Java programming language is the primary way to produce code that will be deployed as byte code in a Java virtual machine (JVM); byte code compilers are also available for other languages, including Ada, JavaScript, Kotlin (Google's preferred Android language), Python, and Ruby. In addition, several languages have been designed to run natively on the JVM, including Clojure, Groovy, and Scala. Java syntax borrows heavily from C and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java Class Loader
The Java class loader, part of the Java Runtime Environment, dynamically loads Java classes into the Java Virtual Machine. Usually classes are only loaded on demand. The virtual machine will only load the class files required for executing the program. The Java run time system does not need to know about files and file systems as this is delegated to the class loader. A software library is a collection of related object code. In the Java language, libraries are typically packaged in JAR files. Libraries can contain objects of different types. The most important type of object contained in a Jar file is a Java class. A class can be thought of as a named unit of code. The class loader is responsible for locating libraries, reading their contents, and loading the classes contained within the libraries. This loading is typically done "on demand", in that it does not occur until the class is called by the program. A class with a given name can only be loaded once by a given class load ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semicolon
The semicolon (or semi-colon) is a symbol commonly used as orthographic punctuation. In the English language, a semicolon is most commonly used to link (in a single sentence) two independent clauses that are closely related in thought, such as when restating the preceding idea with a different expression. When a semicolon joins two or more ideas in one sentence, those ideas are then given equal rank. Semicolons can also be used in place of commas to separate items in a list, particularly when the elements of the list themselves have embedded commas. The semicolon is one of the least understood of the standard marks, and is not frequently used by many English speakers. In the QWERTY keyboard layout, the semicolon resides in the unshifted homerow beneath the little finger of the right hand and has become widely used in programming languages as a statement separator or terminator. History In 1496, the semicolon is attested in Pietro Bembo's book ' printed by Aldo Manuz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colon (punctuation)
The colon, , is a punctuation mark consisting of two equally sized dots aligned vertically. A colon often precedes an explanation, a list, or a quoted sentence. It is also used between hours and minutes in time, between certain elements in medical journal citations, between chapter and verse in Bible citations, between two numbers in a ratio, and, in the US, for salutations in business letters and other formal letters. History In Ancient Greek, in rhetoric and prosody, the term (', 'limb, member of a body') did not refer to punctuation, but to a member or section of a complete thought or passage; see also '' Colon (rhetoric)''. From this usage, in palaeography, a colon is a clause or group of clauses written as a line in a manuscript.''Oxford English Dictionary'', 1st ed. "colon, ''n.2''" Oxford University Press (Oxford), 1891. In the 3rd century BC, Aristophanes of Byzantium is alleged to have devised a punctuation system, in which the end of such a was thought to oc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mac OS X
macOS, previously OS X and originally Mac OS X, is a Unix, Unix-based operating system developed and marketed by Apple Inc., Apple since 2001. It is the current operating system for Apple's Mac (computer), Mac computers. Within the market of Desktop computer, desktop and laptop computers, it is the Usage share of operating systems#Desktop and laptop computers, second most widely used desktop OS, after Microsoft Windows and ahead of all Linux distributions, including ChromeOS and SteamOS. , the most recent release of macOS is MacOS Sequoia, macOS 15 Sequoia, the 21st major version of macOS. Mac OS X succeeded classic Mac OS, the primary Mac operating systems, Macintosh operating system from 1984 to 2001. Its underlying architecture came from NeXT's NeXTSTEP, as a result of NeXT#1997–2006: Acquisition by Apple, Apple's acquisition of NeXT, which also brought Steve Jobs back to Apple. The first desktop version, Mac OS X 10.0, was released on March 24, 2001. Mac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix
Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others. Initially intended for use inside the Bell System, AT&T licensed Unix to outside parties in the late 1970s, leading to a variety of both academic and commercial Unix variants from vendors including University of California, Berkeley ( BSD), Microsoft (Xenix), Sun Microsystems ( SunOS/ Solaris), HP/ HPE ( HP-UX), and IBM ( AIX). The early versions of Unix—which are retrospectively referred to as " Research Unix"—ran on computers such as the PDP-11 and VAX; Unix was commonly used on minicomputers and mainframes from the 1970s onwards. It distinguished itself from its predecessors as the first portable operating system: almost the entire operating system is written in the C programming language (in 1973), which allows U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Command-line Argument
A command-line interface (CLI) is a means of interacting with software via command (computing), commands each formatted as a line of text. Command-line interfaces emerged in the mid-1960s, on computer terminals, as an interactive and more user-friendly alternative to the non-interactive mode available with punched cards. For a long time, a CLI was the most common interface for software, but today a graphical user interface (GUI) is more common. Nonetheless, many programs such as operating system and software development utility software, utilities still provide CLI. A CLI enables automation, automating computer program, programs since commands can be stored in a scripting language, script computer file, file that can be used repeatedly. A script allows its contained commands to be executed as group; as a program; as a command. A CLI is made possible by command-line interpreters or command-line processors, which are programs that execute input commands. Alternatives to a CLI ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java 6
The Java language has undergone several changes since JDK 1.0 as well as numerous additions of classes and packages to the standard library. Since J2SE 1.4, the evolution of the Java language has been governed by the Java Community Process (JCP), which uses ''Java Specification Requests'' (JSRs) to propose and specify additions and changes to the Java platform. The language is specified by the ''Java Language Specification'' (JLS); changes to the JLS are managed undeJSR 901 In September 2017, Mark Reinhold, chief Architect of the Java Platform, proposed to change the release train to "one feature release every six months" rather than the then-current two-year schedule. This proposal took effect for all following versions, and is still the current release schedule. In addition to the language changes, other changes have been made to the Java Class Library over the years, which has grown from a few hundred classes in JDK 1.0 to over three thousand in J2SE ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
