Smalltalk is a purely object oriented programming language (OOP) that was originally created in the 1970s for educational use, specifically for constructionist learning , but later found use in business. It was created at Xerox PARC by Learning Research Group (LRG) scientists, including Alan Kay , Dan Ingalls , Adele Goldberg , Ted Kaehler , Diana Merry , and Scott Wallace.
100-421: JRE can mean Java Runtime Environment The Joe Rogan Experience JR East, see East Japan Railway Company Jeunes Restaurateurs d’Europe Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title JRE . If an internal link led you here, you may wish to change the link to point directly to
200-412: A string literal . For example: If the sequence does not include whitespace or punctuation characters, this can also be written as: Arrays: defines an array of four integers. defines a seven element array whose first element is a literal array, second element a byte array, third element the string 'four', and so on. Many implementations support the following literal syntax for ByteArrays: defines
300-673: A trademark search revealed that Oak Technology used the name Oak . Sun priced Java licenses below cost to gain market share. Although Java 1.0a became available for download in 1994, the first public release of Java, Java 1.0a2 with the HotJava browser, came on May 23, 1995, announced by Gage at the SunWorld conference. Accompanying Gage's announcement, Marc Andreessen , Executive Vice President of Netscape Communications Corporation , unexpectedly announced that Netscape browsers would include Java support. On January 9, 1996, Sun Microsystems formed
400-446: A virtual machine ), a compiler and a set of libraries ; there may also be additional servers and alternative libraries that depend on the requirements. Java platforms have been implemented for a wide variety of hardware and operating systems with a view to enable Java programs to run identically on all of them. The Java platform consists of several programs, each of which provides a portion of its overall capabilities. For example,
500-647: A challenging and error-prone task. The team also worried about the C++ language's lack of portable facilities for security, distributed programming , and threading . Finally, they wanted a platform that would port easily to all types of devices. Bill Joy had envisioned a new language combining Mesa and C. In a paper called Further , he proposed to Sun that its engineers should produce an object-oriented environment based on C++. Initially, Gosling attempted to modify and extend C++ (a proposed development that he referred to as "C++ ++ --") but soon abandoned that in favor of creating
600-457: A class's method dictionary. The part of the class hierarchy that defines classes can add new classes to the system. The system is extended by running Smalltalk-80 code that creates or defines classes and methods. In this way a Smalltalk-80 system is a "living" system, carrying around the ability to extend itself at run time. One can even extend the compiler at run-time; indeed this is how the Compiler
700-454: A code snippet by Ralph Johnson , demonstrating all the basic standard syntactic elements of methods: The following examples illustrate the most common objects which can be written as literal values in Smalltalk-80 methods. Numbers. The following list illustrates some of the possibilities. The last two entries are a binary and a hexadecimal number, respectively. The number before the 'r'
800-464: A larger program of Advanced Research Projects Agency (ARPA) funded research that in many ways defined the modern world of computing. In addition to Smalltalk, working prototypes of things such as hypertext , GUIs, multimedia , the mouse, telepresence , and the Internet were developed by ARPA researchers in the 1960s. Alan Kay (one of the inventors of Smalltalk) also described a tablet computer he named
900-407: A lot of leeway to implementors regarding the implementation details. Since Java 1.3, JRE from Oracle contains a JVM called HotSpot. It has been designed to be a high-performance JVM. To speed-up code execution, HotSpot relies on just-in-time compilation. To speed-up object allocation and garbage collection, HotSpot uses generational heap. The Java virtual machine heap is the area of memory used by
1000-513: A new language, which he called Oak , after the tree that stood just outside his office. By the summer of 1992, the team could demonstrate portions of the new platform, including the Green OS , the Oak language, the libraries, and the hardware. Their first demonstration, on September 3, 1992, focused on building a personal digital assistant (PDA) device named Star7 that had a graphical interface and
1100-643: A number of facilities such as distributed Smalltalk where messages are exchanged between multiple Smalltalk systems, database interfaces where objects are transparently faulted out of a database, promises , etc. The design of distributed Smalltalk influenced such systems as CORBA . Smalltalk-80 syntax is rather minimalist, based on only a handful of declarations and reserved words. In fact, only six "keywords" are reserved in Smalltalk: true , false , nil , self , super , and thisContext . These are properly termed pseudo-variables , identifiers that follow
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#17328773114031200-610: A proposal for a set-top box platform. However, the cable industry felt that their platform gave too much control to the user, so Firstperson lost their bid to SGI . An additional deal with The 3DO Company for a set-top box also failed to materialize. Unable to generate interest within the television industry, the company was rolled back into Sun. In June and July 1994 – after three days of brainstorming with John Gage (the Director of Science for Sun), Gosling, Joy, Naughton, Wayne Rosing , and Eric Schmidt –
1300-466: A short delay during loading and once they have "warmed up" by being all or mostly JIT-compiled, tend to run about as fast as native programs. Since JRE version 1.2, Sun's JVM implementation has included a just-in-time compiler instead of an interpreter. Although Java programs are cross-platform or platform independent, the code of the Java Virtual Machines (JVM) that execute these programs
1400-610: A small office on Sand Hill Road in Menlo Park, California . They aimed to develop new technology for programming next-generation smart appliances, which Sun expected to offer major new opportunities. The team originally considered using C++, but rejected it for several reasons. Because they were developing an embedded system with limited resources, they decided that C++ needed too much memory and that its complexity led to developer errors. The language's lack of garbage collection meant that programmers had to manually manage system memory,
1500-495: A smart agent called "Duke" to assist the user. In November of that year, the Green Project was spun off to become Firstperson , a wholly owned subsidiary of Sun Microsystems, and the team relocated to Palo Alto, California . The Firstperson team had an interest in building highly interactive devices, and when Time Warner issued a request for proposal (RFP) for a set-top box , Firstperson changed their target and responded with
1600-457: A spelling corrector. Each release consisted of a virtual image (platform-independent file with object definitions) and a virtual machine specification. ANSI Smalltalk has been the standard language reference since 1998. Two currently popular Smalltalk implementation variants are descendants of those original Smalltalk-80 images. Squeak is an open source implementation derived from Smalltalk-80 Version 1 by way of Apple Smalltalk. VisualWorks
1700-501: A standard interface for the Java applications to perform those tasks. Finally, when some underlying platform does not support all of the features a Java application expects, the class libraries work to gracefully handle the absent components, either by emulation to provide a substitute, or at least by providing a consistent way to check for the presence of a specific feature. The word "Java", alone, usually refers to Java programming language that
1800-514: A string: Two equal strings (strings are equal if they contain all the same characters) can be different objects residing in different places in memory. In addition to strings, Smalltalk has a class of character sequence objects named Symbol. Symbols are guaranteed to be unique—there can be no two equal symbols which are different objects. Because of that, symbols are very cheap to compare and are often used for language artifacts such as message selectors (see below). Symbols are written as # followed by
1900-630: A supported version. Oracle released the last free-for-commercial-use public update for the legacy Java 8 LTS in January 2019, and will continue to support Java 8 with public updates for personal use indefinitely. Oracle extended support for Java 6 ended in December 2018. The Java platform is a suite of programs that facilitate developing and running programs written in the Java programming language. A Java platform includes an execution engine (called
2000-516: A toolkit for developing collaborative applications Croquet Project , and the Open Cobalt virtual world application. GNU Smalltalk is a free software implementation of a derivative of Smalltalk-80 from the GNU project. Pharo Smalltalk is a fork of Squeak oriented toward research and use in commercial environments. As of 2016, a significant development that has spread across all Smalltalk environments
2100-530: A very simple memory model where objects are allocated on the heap (while some implementations e.g. all currently supported by Oracle, may use escape analysis optimization to allocate on the stack instead) and all variables of object types are references . Memory management is handled through integrated automatic garbage collection performed by the JVM. The latest version is Java 22 released in March 2024, and
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#17328773114032200-480: Is a JIT (Just In Time) compiler within the Java Virtual Machine , or JVM. The JIT compiler translates the Java bytecode into native processor instructions at run-time and caches the native code in memory during execution. The use of bytecode as an intermediate language permits Java programs to run on any platform that has a virtual machine available. The use of a JIT compiler means that Java applications, after
2300-606: 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
2400-512: Is a structurally reflective system which structure is defined by Smalltalk-80 objects. The classes and methods that define the system are also objects and fully part of the system that they help define. The Smalltalk compiler, which is itself written in Smalltalk and exists alongside all the other code in the system, compiles textual source code into method objects, typically instances of CompiledMethod . These get added to classes by storing them in
2500-421: Is always private to that object. Other objects can query or change that state only by sending requests (messages) to the object to do so. Any message can be sent to any object: when a message is received, the receiver determines whether that message is appropriate. If the message is not understood by the object then the virtual machine sends the doesNotUnderstand: message with the original message as an argument, and
2600-621: Is derived from Smalltalk-80 version 2 by way of Smalltalk-80 2.5 and ObjectWorks (both products of ParcPlace Systems, a Xerox PARC spin-off company formed to bring Smalltalk to the market). As an interesting link between generations, in 2001, Vassili Bykov implemented Hobbes, a virtual machine running Smalltalk-80 inside VisualWorks. ( Dan Ingalls later ported Hobbes to Squeak.) During the late 1980s to mid-1990s, Smalltalk environments, including support, training and add-ons, were sold by two competing organizations: ParcPlace Systems and Digitalk, both California based. ParcPlace Systems tended to focus on
2700-425: Is developed and maintained. Since the classes are objects, they can be asked questions such as "what methods do you implement?" or "what fields/slots/instance variables do you define?". So objects can easily be inspected, copied, (de) serialized and so on with generic code that applies to any object in the system. Smalltalk-80 also provides computational reflection, the ability to observe the computational state of
2800-569: Is implemented on top of the built-in constructs by the standard Smalltalk class library. (For performance reasons, implementations may recognize and treat as special some of those messages; however, this is only an optimization and is not coded into the language syntax.) The adage that "Smalltalk syntax fits on a postcard " may have originated in Alan Kay's original conception of the language, as related by him in practically every of tens or hundreds of public lectures, op. cit., or perhaps it could refer to
2900-530: Is implemented using this facility. One of the more interesting uses of this is in the Seaside web framework which relieves the programmer of dealing with the complexity of a Web Browser's back button by storing continuations for each edited page and switching between them as the user navigates a web site. Programming the web server using Seaside can then be done using a more conventional programming style. As with message sending Smalltalk-80 virtual machines optimize away
3000-805: Is not. Every supported operating platform has its own JVM. The Java Development Kit (JDK) is a distribution of Java technology by Oracle Corporation . It implements the Java Language Specification (JLS) and the Java Virtual Machine Specification (JVMS) and provides the Standard Edition (SE) of the Java Application Programming Interface (API). It is derivative of the community driven OpenJDK which Oracle stewards. It provides software for working with Java applications. Examples of included software are
3100-467: Is now termed Smalltalk-72 and influenced the development of the Actor model . Its syntax and execution model were very different from modern Smalltalk variants. After significant revisions which froze some aspects of execution semantics to gain performance (by adopting a Simula -like class inheritance model of execution), Smalltalk-76 was created. This system had a development environment featuring most of
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3200-415: Is provided to simplify the programmer's job. This code is typically provided as a set of dynamically loadable libraries that applications can call at runtime. Because the Java platform is not dependent on any specific operating system, applications cannot rely on any of the pre-existing OS libraries. Instead, the Java platform provides a comprehensive set of its own standard class libraries containing many of
3300-451: Is similar in purpose to the JVM. Like the JVM, the CLR provides memory management through automatic garbage collection, and allows .NET byte code to run on multiple operating systems. .NET included a Java-like language first named J++ , then called Visual J# that was incompatible with the Java specification. It was discontinued 2007, and support for it ended in 2015. The JVM specification gives
3400-641: Is summarized in the commonly heard phrase "In Smalltalk everything is an object", which may be more accurately expressed as "all values are objects", as variables are not. Since all values are objects, classes are also objects. Each class is an instance of the metaclass of that class. Metaclasses in turn are also objects, and are all instances of a class named Metaclass. Classes contain method dictionaries that map selectors (the equivalent of function procedure names in other languages) to method objects, objects that are executed to evaluate messages. Classes inherit from other classes, with either Object or ProtoObject at
3500-404: Is the radix or base. The base does not have to be a power of two; for example 36rSMALLTALK is a valid number equal to 80738163270632 decimal. Characters are written by preceding them with a dollar sign: Strings are sequences of characters enclosed in single quotes: To include a quote in a string, escape it using a second quote: Double quotes do not need escaping, since single quotes delimit
3600-419: Is the increasing usage of two web frameworks, Seaside and AIDA/Web , to simplify the building of complex web applications. Seaside has seen considerable market interest with Cincom, Gemstone, and Instantiations incorporating and extending it. Smalltalk was one of many object-oriented programming languages based on Simula . Smalltalk is also one of the most influential programming languages. Virtually all of
3700-482: Is the part of the system that implements the programming system itself, and developers can use the meta-model to do things like walk through, examine, and modify code in the running system, or find all the instances of a certain kind of structure (e.g., all instances of the Method class in the meta-model). Smalltalk-80 is a totally reflective system. Smalltalk-80 provides both structural and computational reflection. Smalltalk
3800-493: The .NET Framework , appearing since 2002, which incorporates many of the successful aspects of Java. .NET was built from the ground-up to support multiple programming languages, while the Java platform was initially built to support only the Java language, although many other languages have been made for JVM since. Like Java, .NET languages compile to byte code and are executed by the Common Language Runtime (CLR), which
3900-572: The Dynabook which resembles modern tablet computers like the iPad. Smalltalk environments were often the first to develop what are now common object-oriented software design patterns. One of the most popular is the model–view–controller (MVC) pattern for user interface design. The MVC pattern enables developers to have multiple consistent views of the same underlying data. It's ideal for software development environments, where there are various views (e.g., entity-relation, dataflow, object model, etc.) of
4000-535: The Java compiler , which converts Java source code into Java bytecode (an intermediate language for the JVM), is provided as part of the Java Development Kit (JDK). The Java Runtime Environment (JRE), complementing the JVM with a just-in-time (JIT) compiler , converts intermediate bytecode into native machine code on the fly. The Java platform also includes an extensive set of libraries. The essential components in
4100-623: 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 C++ , but object-oriented features are modeled after Smalltalk and Objective-C . Java eschews certain low-level constructs such as pointers and has
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4200-513: The Oracle Solaris operating system and SPARC architecture. The Java Runtime Environment (JRE) released by Oracle is a freely available software distribution containing a stand-alone JVM (HotSpot), the Java standard library ( Java Class Library ), a configuration tool, and—until its discontinuation in JDK 9—a browser plug-in. It is the most common Java environment installed on personal computers in
4300-583: The Stack Overflow Developer Survey in 2017, but it was not among the 26 most loved programming languages of the 2018 survey. There are a large number of Smalltalk variants. The unqualified word Smalltalk is often used to indicate the Smalltalk-80 language and compatible VM, the first version to be made publicly available and created in 1980. The first hardware-environments which ran the Smalltalk VMs were Xerox Alto computers. Smalltalk
4400-541: The for-each loop , generics , autoboxing and var-args . Java SE 6 (December 11, 2006) – Codename Mustang . It was bundled with a database manager and facilitates the use of scripting languages with the JVM (such as JavaScript using Mozilla 's Rhino engine). As of this version, Sun replaced the name "J2SE" with Java SE and dropped the ".0" from the version number. Other major changes include support for pluggable annotations ( JSR 269 ), many GUI improvements, including native UI enhancements to support
4500-523: The C++/ C programming languages. Engineer Patrick Naughton had become increasingly frustrated with the state of Sun's C++ and C application programming interfaces (APIs) and tools, as well as with the way the NeWS project was handled by the organization. Naughton informed Scott McNealy about his plan of leaving Sun and moving to NeXT ; McNealy asked him to pretend he was God and send him an e-mail explaining how to fix
4600-517: The Digitalk products initially tried to reach a wider audience with a lower price. IBM initially supported the Digitalk product, but then entered the market with a Smalltalk product in 1995 named VisualAge/Smalltalk. Easel introduced Enfin at this time on Windows and OS/2. Enfin became far more popular in Europe, as IBM introduced it into IT shops before their development of IBM Smalltalk (later VisualAge). Enfin
4700-408: The JVM for dynamic memory allocation . In HotSpot the heap is divided into generations : The permanent generation (or permgen ) was used for class definitions and associated metadata prior to Java 8. Permanent generation was not part of the heap. The permanent generation was removed from Java 8. Originally there was no permanent generation, and objects and classes were stored together in
4800-436: The JVM specification. (Instead, Google 's Android development tools take Java programs as input and output Dalvik bytecode, which is the native input format for the virtual machine on Android devices.) The last Critical Path Update version of JRE with an Oracle BCL Agreement was 8u201 and, the last Patch Set Update version with the same license was 8u202. The last Oracle JRE implementation, regardless of its licensing scheme,
4900-467: The Java Virtual Machine as separate entities, so that they are no longer considered a single unit. Third parties have produced many compilers or interpreters that target the JVM. Some of these are for existing languages, while others are for extensions to the Java language. These include: The success of Java and its write once, run anywhere concept has led to other similar efforts, notably
5000-545: The Java libraries provide the programmer a well-known set of functions to perform common tasks, such as maintaining lists of items or performing complex string parsing. Second, the class libraries provide an abstract interface to tasks that would normally depend heavily on the hardware and operating system. Tasks such as network access and file access are often heavily intertwined with the distinctive implementations of each platform. The java.net and java.io libraries implement an abstraction layer in native OS code, then provide
5100-621: The Java platform. The Java Language Specification (JLS) specifies the language; changes to the JLS are managed under JSR 901. Sun released JDK 1.1 on February 19, 1997. Major additions included an extensive retooling of the Abstract Window Toolkit (AWT) event model, inner classes added to the language, JavaBeans , and Java Database Connectivity (JDBC). J2SE 1.2 (December 8, 1998) – Codename Playground . This and subsequent releases through J2SE 5.0 were rebranded Java 2 and
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#17328773114035200-517: The Java virtual machine, a compiler, performance monitoring tools, a debugger, and other utilities that Oracle considers useful for Java programmers. Oracle releases the current version of the software under the Oracle No-Fee Terms and Conditions (NFTC) license. Oracle releases binaries for the x86-64 architecture for Windows, macOS, and Linux based operating systems, and for the aarch64 architecture for macOS and Linux. Previous versions supported
5300-524: The JavaSoft group to develop the technology. While the so-called Java applets for web browsers no longer are the most popular use of Java (with it e.g. more used server-side) or the most popular way to run code client-side (JavaScript took over as more popular), it still is possible to run Java (or other JVM languages such as Kotlin) in web browsers, even after JVM support has been dropped from them, using e.g. TeaVM . On November 13, 2006, Sun Microsystems made
5400-543: The Project Nashorn JavaScript runtime, a new Date and Time API inspired by Joda Time, and the removal of PermGen. This version is not officially supported on the Windows XP platform, but is known to work there. Thus, due to the end of Java 7's lifecycle it is the recommended version for XP users. Previously, only an unofficial manual installation method had been described for Windows XP SP3. It refers to JDK8,
5500-491: The Smalltalk programming environment. Having undergone significant industry development toward other uses, including business and database functions, Smalltalk is still in use today. When first publicly released, Smalltalk-80 presented numerous foundational ideas for the nascent field of object-oriented programming (OOP). Since inception, the language provided interactive programming via an integrated development environment . This requires reflection and late binding in
5600-505: The Unix/Sun microsystems market, while Digitalk focused on Intel-based PCs running Microsoft Windows or IBM's OS/2. Both firms struggled to take Smalltalk mainstream due to Smalltalk's substantial memory needs, limited run-time performance, and initial lack of supported connectivity to SQL -based relational database servers. While the high price of ParcPlace Smalltalk limited its market penetration to mid-sized and large commercial organizations,
5700-694: The bulk of its implementation of Java available under the GNU General Public License (GPL). The Java language has undergone several changes since the release of JDK ( Java Development Kit ) 1.0 on January 23, 1996, as well as numerous additions of classes and packages to the standard library . Since J2SE 1.4 the Java Community Process (JCP) has governed the evolution of the Java Language. The JCP uses Java Specification Requests (JSRs) to propose and specify additions and changes to
5800-693: The business. In 1999, Seagull Software acquired the ObjectShare Java development lab (including the original Smalltalk/V and Visual Smalltalk development team), and still owns VisualSmalltalk, although worldwide distribution rights for the Smalltalk product remained with ObjectShare who then sold them to Cincom . VisualWorks was sold to Cincom and is now part of Cincom Smalltalk. Cincom has backed Smalltalk strongly, releasing multiple new versions of VisualWorks and ObjectStudio each year since 1999. Cincom , GemTalk, and Instantiations, continue to sell Smalltalk environments. IBM ended VisualAge Smalltalk, having in
5900-764: The central concept in Smalltalk-80 (but not in Smalltalk-72) is that of an object . An object is always an instance of a class . Classes are "blueprints" that describe the properties and behavior of their instances. For example, a GUI's window class might declare that windows have properties such as the label, the position and whether the window is visible or not. The class might also declare that instances support operations such as opening, closing, moving and hiding. Each particular window object would have its own values of those properties, and each of them would be able to perform operations defined by its class. A Smalltalk object can do exactly three things: The state an object holds
6000-534: The company. Naughton envisioned the creation of a small team that could work autonomously without the bureaucracy that was stalling other Sun projects. McNealy forwarded the message to other important people at Sun, and the Stealth Project started. The Stealth Project was soon renamed to the Green Project , with James Gosling and Mike Sheridan joining Naughton. Together with other engineers, they began work in
6100-684: The core classes. A Java Plug-in was released, and Sun's JVM was equipped with a JIT compiler for the first time. J2SE 1.3 (May 8, 2000) – Codename Kestrel . Notable changes included the bundling of the HotSpot JVM (the HotSpot JVM was first released in April, 1999 for the J2SE ;1.2 JVM), JavaSound , Java Naming and Directory Interface (JNDI) and Java Platform Debugger Architecture (JPDA). J2SE 1.4 (February 6, 2002) – Codename Merlin . This became
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#17328773114036200-471: The default implementation of doesNotUnderstand: raises an exception that if not caught opens the system's debugger. Alan Kay has commented that despite the attention given to objects, messaging is the most important concept in Smalltalk: "The big idea is 'messaging'—that is what the kernel of Smalltalk/Squeak is all about (and it's something that was never quite completed in our Xerox PARC phase)." Unlike most other languages, Smalltalk code can be modified while
6300-972: The developing platform for Java that also includes a fully functioning Java Runtime Environment . Java 8 is supported on Windows Server 2008 R2 SP1, Windows Vista SP2 and Windows 7 SP1, Ubuntu 12.04 LTS and higher (and some other OSes). Java SE 9 and 10 have higher system requirements, i.e. Windows 7 or Server 2012 (and web browser minimum certified is upped to Internet Explorer 11 or other web browsers), and Oracle dropped 32-bit compatibility for all platforms, i.e. only Oracle's " 64-bit Java virtual machines (JVMs) are certified". Smalltalk In Smalltalk, executing programs are built of opaque, atomic, so-called objects, which are instances of template code stored in classes. These objects intercommunicate by passing of messages, via an intermediary virtual machine environment (VM). A relatively small number of objects, called primitives, are not amenable to live redefinition, sometimes being defined independently of
6400-576: The discontinuation of the Java browser plug-in, any web page might have potentially run a Java applet, which provided an easily accessible attack surface to malicious web sites. In 2013 Kaspersky Labs reported that the Java plug-in was the method of choice for computer criminals. Java exploits are included in many exploit packs that hackers deploy onto hacked web sites. Java applets were removed in Java 11, released on September 25, 2018. The Java platform and language began as an internal project at Sun Microsystems in December 1990, providing an alternative to
6500-423: The expensive use of contexts internally, providing the illusion and flexibility of a spaghetti stack without most its costs. Essentially context objects are created lazily as required, for example when a message is sent to the thisContext variable. An example of how Smalltalk can use reflection is the mechanism for handling errors. When an object is sent a message that it does not implement, the virtual machine sends
6600-436: The first being the sender of the former. In this way the stack is a linked list of context objects, and the debugger is essentially an inspector of this "spaghetti stack". By sending messages to thisContext a method activation can ask questions like "who sent this message to me". These facilities make it possible to implement coroutines or Prolog -like back-tracking without modifying the virtual machine. The exception system
6700-565: The first release of the Java platform developed under the Java Community Process as JSR 59. Major changes included regular expressions modeled after Perl , exception chaining , an integrated XML parser and XSLT processor ( JAXP ), and Java Web Start . J2SE 5.0 (September 30, 2004) – Codename Tiger . It was originally numbered 1.5, which is still used as the internal version number. Developed under JSR 176, Tiger added several significant new language features including
6800-660: The intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=JRE&oldid=1148903318 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Java Runtime Environment 21.0.5 LTS (October 15, 2024 ; 40 days ago ( 2024-10-15 ) ) [±] 17.0.13 LTS (October 15, 2024 ; 40 days ago ( 2024-10-15 ) ) [±] 11.0.25 LTS (October 15, 2024 ; 40 days ago ( 2024-10-15 ) ) [±] Java
6900-496: The language execution of code . Later development has led to at least one instance of Smalltalk execution environment which lacks such an integrated graphical user interface or front-end. Smalltalk-like languages are in active development and have gathered communities of users around them. American National Standards Institute (ANSI) Smalltalk was ratified in 1998 and represents the standard version of Smalltalk. Smalltalk took second place for "most loved programming language" in
7000-521: The laptop and desktop form factor . Mobile phones including feature phones and early smartphones that ship with a JVM are most likely to include a JVM meant to run applications targeting Micro Edition of the Java platform. Meanwhile, most modern smartphones, tablet computers , and other handheld PCs that run Java apps are most likely to do so through support of the Android operating system , which includes an open source virtual machine incompatible with
7100-646: The last two being vectors of bytes. Consequently Smalltalk can evaluate 52 factorial to produce 80658175170943878571660636856403766975289505440883277824000000000000. The transition from small to large integers is transparent to the programmer; variables do not require type declarations. This makes the system both concise and flexible. A programmer can change or extend (through subclassing ) the classes that implement what in other languages would be primitive values, so that new behavior can be defined for their instances—for example, to implement new control structures—or even so that their existing behavior will be changed. This fact
7200-524: The late 1990s decided to back Java instead and, as of 2005 , is supported by Instantiations, Inc. Instantiations renamed the product VA Smalltalk (VAST Platform) and continue to release new versions yearly. The open Squeak implementation has an active community of developers, including many of the original Smalltalk community, and was used to provide the Etoys environment on the One Laptop per Child (OLPC) project,
7300-827: The latest long-term support (LTS) version is Java 21 released in September 2023, which is one of a few LTS versions still supported, down to Java 8 LTS. As an open source platform, Java has many distributors, including Amazon , IBM , Azul Systems , and AdoptOpenJDK . Distributions include Amazon Corretto, Zulu, AdoptOpenJDK, and Liberica. Regarding Oracle, it distributes Java 8, and also makes available e.g. Java 11, both also currently supported LTS versions. Oracle (and others) "highly recommend that you uninstall older versions of Java" than Java 8, because of serious risks due to unresolved security issues. Since Java 9 (as well as versions 10, and 12–16, and 18–20) are no longer supported, Oracle advises its users to "immediately transition" to
7400-492: The look and feel of Windows Vista , and improvements to the Java Platform Debugger Architecture (JPDA) & JVM Tool Interface for better monitoring and troubleshooting. Java SE 7 (July 28, 2011) – Codename Dolphin . This version developed under JSR 336. It added many small language changes including strings in switch, try-with-resources and type inference for generic instance creation. The JVM
7500-452: The now familiar tools, including a class library code browser/editor. Smalltalk-80 added metaclasses , to help maintain the "everything is an object" (except variables) paradigm by associating properties and behavior with individual classes, and even primitives such as integer and Boolean values (for example, to support different ways to create instances). Smalltalk-80 was the first language variant made available outside of PARC. In 1981, it
7600-411: The object the doesNotUnderstand: message with a reification of the message as an argument. The message (another object, an instance of Message ) contains the selector of the message and an Array of its arguments. In an interactive Smalltalk system the default implementation of doesNotUnderstand: is one that opens an error window (a Notifier) reporting the error to the user. Through this and
7700-476: The object-oriented languages that came after— Flavors , CLOS , Objective-C , Java , Python , Ruby , and many others—were influenced by Smalltalk. Smalltalk was also one of the most popular languages for agile software development methods, rapid application development (RAD) or prototyping, and software design patterns . The highly productive environment provided by Smalltalk platforms made them ideal for rapid, iterative development. Smalltalk emerged from
7800-458: The platform are the Java language compiler, the libraries, and the runtime environment in which Java intermediate bytecode executes according to the rules laid out in the virtual machine specification. Different platforms target different classes of device and application domains : Java Platform, Standard Edition (Java SE) is a computing platform for development and deployment of portable code for desktop and server environments. Java SE
7900-471: The reflective facilities the user can examine the context in which the error occurred, redefine the offending code, and continue, all within the system, using Smalltalk-80's reflective facilities. By creating a class that understands (implements) only doesNotUnderstand:, one can create an instance that can intercept any message sent to it via its doesNotUnderstand: method. Such instances are called transparent proxies. Such proxies can then be used to implement
8000-410: The root of the class hierarchy. Sending a message to an object at the most abstract involves fetching the class of the receiver (the object being sent the message) and looking up the message's selector in the class's method dictionary, followed by the superclass and so on until the method is found or doesNotUnderstand is sent. Smalltalk virtual machines use various techniques to speed up message lookup so
8100-462: The rules for variable identifiers but denote bindings that a programmer cannot change. The true , false , and nil pseudo-variables are singleton instances. self and super refer to the receiver of a message within a method activated in response to that message, but sends to super are looked up in the superclass of the method's defining class rather than the class of the receiver, which allows methods in subclasses to invoke methods of
8200-495: The same area. But as class unloading occurs much more rarely than objects are collected, moving class structures to a specific area allowed significant performance improvements. The Java JRE is installed on a large number of computers. End users with an out-of-date version of JRE therefore are vulnerable to many known attacks. This led to the widely shared belief that Java is inherently insecure. Since Java 1.7, Oracle's JRE for Windows includes automatic update functionality. Before
8300-473: The same name in superclasses. thisContext refers to the current activation record. The only built-in language constructs are message sends, assignment, method return and literal syntax for some objects. From its origins as a language for children of all ages, standard Smalltalk syntax uses punctuation in a manner more like English than mainstream coding languages. The remainder of the language, including control structures for conditional evaluation and iteration,
8400-465: The same reusable functions commonly found in modern operating systems. Most of the system library is also written in Java. For instance, the Swing library paints the user interface and handles the events itself, eliminating many subtle differences between how different platforms handle components. The Java class libraries serve three purposes within the Java platform. First, like other standard code libraries,
8500-565: The same underlying specification. Also, for simulations or games where the underlying model may be viewed from various angles and levels of abstraction. In addition to the MVC pattern, the Smalltalk language and environment were influential in the history of the graphical user interface (GUI) and the what you see is what you get ( WYSIWYG ) user interface, font editors, and desktop metaphors for UI design. The powerful built-in debugging and object inspection tools that came with Smalltalk environments set
8600-406: The sense that they are instances of corresponding classes, and operations on them are invoked by sending messages. For efficiency and generality integers are implemented by four classes, Integer, the abstract superclass of all integers, SmallInteger, whose instances fit in a machine word, for example having a 61-bit signed range in a 64-bit implementation, LargePositiveInteger and LargeNegativeInteger,
8700-449: The standard for all the integrated development environments , starting with Lisp Machine environments, that came after. Smalltalk uses several commands that rhyme with the "-ect" suffix. This was inspired by a line from the 1967 Arlo Guthrie monologue " Alice's Restaurant Massacree ," in which Guthrie underwent a battery of being "injected, inspected, detected, infected, neglected and selected." As in other object-oriented languages,
8800-502: The system is running. Live coding and applying fixes 'on-the-fly' is a dominant programming methodology for Smalltalk and is one of the main reasons for its productivity. Smalltalk is a "pure" object-oriented programming language, meaning that, unlike C++ and Java , there are no primitive types. All values are represented as objects and computation on integers uses message sending just like any other object. In Smalltalk, types such as integers, Booleans and characters are also objects, in
8900-459: The system provides both a simple consistent message binding mechanism and good efficiency. Code blocks —Smalltalk's way of expressing anonymous functions —are also objects. They have a very lightweight syntax and are used throughout the system to implement control structures, especially for the Collection hierarchy. Reflection is a feature of having a meta-model as Smalltalk does. The meta-model
9000-410: The system. In languages derived from the original Smalltalk-80 the current activation of a method is accessible as an object named via a pseudo-variable (one of the six reserved words), thisContext , which corresponds to a stack frame in conventional language implementations, and is called a "context". Sending a message is done within some context, and to evaluate the message another context is created,
9100-468: The team re-targeted the platform for the World Wide Web . They felt that with the advent of graphical web browsers like Mosaic the Internet could evolve into the same highly interactive medium that they had envisioned for cable TV. As a prototype, Naughton wrote a small browser, WebRunner (named after the movie Blade Runner ), renamed HotJava in 1995. Sun renamed the Oak language to Java after
9200-416: The version name "J2SE" ( Java 2 Platform, Standard Edition ) replaced JDK to distinguish the base platform from J2EE ( Java 2 Platform, Enterprise Edition ) and J2ME ( Java 2 Platform, Micro Edition ). Major additions included reflection , a collections framework, Java IDL (an interface description language implementation for CORBA interoperability), and the integration of the Swing graphical API into
9300-404: Was 9.0.4. Since Java Platform SE 9, the whole platform also was grouped into modules . The modularization of Java SE implementations allows developers to bundle their applications together with all the modules used by them, instead of solely relying on the presence of a suitable Java SE implementation in the user device. In most modern operating systems (OSs), a large body of reusable code
9400-467: Was designed for use with the Java platform. Programming languages are typically outside of the scope of the phrase "platform", although the Java programming language was listed as a core part of the Java platform before Java 7. The language and runtime were therefore commonly considered a single unit. However, an effort was made with the Java ;7 specification to more clearly treat the Java language and
9500-620: Was extended with support for dynamic languages, while the class library was extended among others with a join/fork framework, an improved new file I/O library and support for new network protocols such as SCTP . Java 7 Update 76 was released in January 2015, with expiration date April 14, 2015. In June 2016, after the last public update of Java 7, " remotely exploitable " security bugs in Java 6, 7, and 8 were announced. Java SE 8 (March 18, 2014) – Codename Kenai . Notable changes include language-level support for lambda expressions ( closures ) and default methods,
9600-417: Was formerly known as Java 2 Platform, Standard Edition (J2SE). The heart of the Java platform is the "virtual machine" that executes Java bytecode programs. This bytecode is the same no matter what hardware or operating system the program is running under. However, new versions, such as for Java 10 (and earlier), have made small changes, meaning the bytecode is in general only forward compatible . There
9700-514: Was in November 1981. Xerox only distributed Version 1 to Apple, DEC, HP, and Tektronix, but these companies were allowed unrestricted redistribution via any system they built. This encouraged the wide spread of Smalltalk. Later, in 1983, Xerox released Smalltalk-80 Version 2. This version was generally available to the public, although under a restrictive license. Versions 1 and 2 were fairly similar, although Version 2 did have some added features such as
9800-613: Was later acquired by Cincom Systems , and is now sold under the name ObjectStudio , and is part of the Cincom Smalltalk product suite. In 1995, ParcPlace and Digitalk merged into ParcPlace-Digitalk and then rebranded in 1997 as ObjectShare, located in Irvine, CA. ObjectShare ( NASDAQ : OBJS) was traded publicly until 1999, when it was delisted and dissolved. The merged firm never managed to find an effective response to Java as to market positioning, and by 1997 its owners were looking to sell
9900-406: Was shared with Tektronix , Hewlett-Packard , Apple Computer , and DEC for review and debugging on their platforms. The August 1981 issue of Byte Magazine was devoted to Smalltalk-80 and brought its ideas to a large audience. Several books on Smalltalk-80 were also published. Smalltalk-80 became the basis for all future commercial versions of Smalltalk. The final release of Smalltalk-80 Version 1
10000-510: Was the product of research led by Alan Kay at Xerox Palo Alto Research Center (PARC); Alan Kay designed most of the early Smalltalk versions, Adele Goldberg wrote most of the documentation, and Dan Ingalls implemented most of the early versions. The first version, termed Smalltalk-71, was created by Kay in a few mornings on a bet that a programming language based on the idea of message passing inspired by Simula could be implemented in "a page of code". A later variant used for research work
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