1.
Java (software platform)
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Java is used in a wide variety of computing platforms from embedded devices and mobile phones to enterprise servers and supercomputers. While they are less common than standalone Java applications, Java applets run in secure, sandboxed environments to provide many features of native applications, in addition, several languages have been designed to run natively on the JVM, including Scala, Clojure and Apache Groovy. Java syntax borrows heavily from C and C++, but object-oriented features are modeled after Smalltalk, Java eschews certain low-level constructs such as pointers and has a very simple memory model where every object is allocated on the heap and all variables of object types are references. Memory management is handled through integrated automatic garbage collection performed by the JVM, on November 13,2006, Sun Microsystems made the bulk of its implementation of Java available under the GNU General Public License. The latest version is Java 8, the only supported version as of 2016, Oracle has announced that using older versions of their JVM implementation presents serious risks due to unresolved security issues. The Java platform is a suite of programs that facilitate developing and running programs written in the Java programming language. A Java platform will include an engine, a compiler. Java ME, Specifies several different sets of libraries for devices with limited storage, display and it is often used to develop applications for mobile devices, PDAs, TV set-top boxes, and printers. Java SE, For general-purpose use on desktop PCs, servers, Java EE, Java SE plus various APIs which are useful for multi-tier client–server enterprise applications. The Java platform consists of programs, each of which provides a portion of its overall capabilities. For example, the Java compiler, which converts Java source code into Java bytecode, is provided as part of the Java Development Kit, the Java Runtime Environment, complementing the JVM with a just-in-time compiler, converts intermediate bytecode into native machine code on the fly. The Java platform also includes a set of libraries. The heart of the Java platform is the concept of a machine that executes Java bytecode programs. This bytecode is the same no matter what hardware or operating system the program is running under, there is a JIT compiler within the Java Virtual Machine, or JVM. The JIT compiler translates the Java bytecode into native processor instructions at run-time, the use of bytecode as an intermediate language permits Java programs to run on any platform that has a virtual machine available. Since JRE version 1.2, Suns 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 that execute these programs is not. Every supported operating platform has its own JVM, in most modern operating systems, a large body of reusable code is provided to simplify the programmers job. This code is provided as a set of dynamically loadable libraries that applications can call at runtime
2.
Commercial entity
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To have legal personality means to be capable of holding legal rights and obligations within a certain legal system, such as entering into contracts, suing, and being sued. Legal personality is a prerequisite to legal capacity, the ability of any person to amend rights. In international law, consequently, legal personality is a prerequisite for an organization to be able to sign international treaties in its own name. A holder of legal personality is called as a person, Persons are of two kinds, natural persons and juridical persons – entities such as corporations, which are treated in law as if they are persons. While human beings acquire legal personhood when they are born, juridical persons do so when they are incorporated in accordance with law, artificial personality, juridical personality, or juristic personality is the characteristic of a non-living entity regarded by law to have the status of personhood. A juridical or artificial person has a name and has certain rights, protections, privileges, responsibilities. The concept of a person is a fundamental legal fiction. It is pertinent to the philosophy of law, as it is essential to laws affecting a corporation, juridical personality allows one or more natural persons to act as a single entity for legal purposes. In many jurisdictions, artificial personality allows that entity to be considered under law separately from its individual members and they may sue and be sued, enter contracts, incur debt, and own property. Entities with legal personality may also be subjected to legal obligations. An entity with legal personality may shield its members from personal liability, in some common law jurisdictions a distinction is drawn between corporation aggregate and a corporation sole. Historically most corporations sole were ecclesiastical in nature, but a number of public offices are now formed as corporations sole. The concept of personality is not absolute. The concept of a person is now central to Western law in both common-law and civil-law countries, but it is also found in virtually every legal system. Examples are a religious officiant in that capacity, or The Crown in the Commonwealth realms, a corporation aggregate is a corporation constituted by more than one member. Municipal corporations are creatures of statute, other organizations may be created by statute as legal persons, including European economic interest groupings. Unincorporated associations, that is aggregates of two or more persons, are treated as persons in some jurisdictions but not others. Partnerships, an aggregate of two or more persons to carry on a business in common for profit and created by agreement, traditionally, partnerships did not have continuing legal personality, but many jurisdictions now treat them as having an independent legal personality
3.
Source code
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In computing, source code is any collection of computer instructions, possibly with comments, written using a human-readable programming language, usually as ordinary text. The source code of a program is designed to facilitate the work of computer programmers. The source code is often transformed by an assembler or compiler into binary machine code understood by the computer, the machine code might then be stored for execution at a later time. Alternatively, source code may be interpreted and thus immediately executed, most application software is distributed in a form that includes only executable files. If the source code were included it would be useful to a user, programmer or a system administrator, the Linux Information Project defines source code as, Source code is the version of software as it is originally written by a human in plain text. The notion of source code may also be more broadly, to include machine code and notations in graphical languages. It is therefore so construed as to include code, very high level languages. Often there are several steps of program translation or minification between the source code typed by a human and an executable program. The earliest programs for stored-program computers were entered in binary through the front panel switches of the computer and this first-generation programming language had no distinction between source code and machine code. When IBM first offered software to work with its machine, the code was provided at no additional charge. At that time, the cost of developing and supporting software was included in the price of the hardware, for decades, IBM distributed source code with its software product licenses, until 1983. Most early computer magazines published source code as type-in programs, Source code can also be stored in a database or elsewhere. The source code for a piece of software may be contained in a single file or many files. Though the practice is uncommon, a source code can be written in different programming languages. For example, a program written primarily in the C programming language, in some languages, such as Java, this can be done at run time. The code base of a programming project is the larger collection of all the source code of all the computer programs which make up the project. It has become practice to maintain code bases in version control systems. Moderately complex software customarily requires the compilation or assembly of several, sometimes dozens or even hundreds, in these cases, instructions for compilations, such as a Makefile, are included with the source code
4.
Java Management Extensions
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Java Management Extensions is a Java technology that supplies tools for managing and monitoring applications, system objects, devices and service-oriented networks. Those resources are represented by objects called MBeans, in the API, classes can be dynamically loaded and instantiated. Managing and monitoring applications can be designed and developed using the Java Dynamic Management Kit, JSR003 of the Java Community Process defined JMX1.0,1.1 and 1.2. JMX2.0 was being developed under JSR255, the JMX Remote API1.0 for remote management and monitoring is specified by JSR160. An extension of the JMX Remote API for Web Services is being developed under JSR262, adopted early on by the J2EE community, JMX has been a part of J2SE since version 5.0. JMX is a trademark of Oracle Corporation, JMX uses a three-level architecture, The Probe level - also called the Instrumentation level - contains the probes instrumenting the resources The Agent level, or MBeanServer - the core of JMX. It acts as an intermediary between the MBean and the applications, the Remote Management level enables remote applications to access the MBeanServer through connectors and adaptors. A connector provides full access to the MBeanServer API using various communication. Applications can be generic consoles or domain-specific applications, external applications can interact with the MBeans through the use of JMX connectors and protocol adapters. Connectors serve to connect an agent with a remote JMX-enabled management application and this form of communication involves a connector in the JMX agent and a connector client in the management application. Protocol adapters provide a management view of the JMX agent through a given protocol, Management applications that connect to a protocol adapter are usually specific to the given protocol. A managed bean - sometimes simply referred to as an MBean - is a type of JavaBean, managed Beans are particularly used in the Java Management Extensions technology - but with Java EE6 the specification provides for a more detailed meaning of a managed bean. The MBean represents a resource running in the Java virtual machine, Java EE6 provides that a managed bean is a bean that is implemented by a Java class, which is called its bean class. It is a class, or is annotated @Decorator. It is not annotated with an EJB component-defining annotation or declared as an EJB bean class in ejb-jar. xml, no special declaration, such as an annotation, is required to define a managed bean. An MBean can notify the MBeanServer of its changes by implementing the javax. management. NotificationEmitter. The application interested in the MBeans changes registers a listener to the MBeanServer, note that JMX does not guarantee that the listeners will receive all notifications. There are two types of MBean, Standard MBeans implement a business interface containing setters and getters for the attributes
5.
OSGi
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Application life cycle management is implemented via APIs that allow for remote downloading of management policies. The service registry allows bundles to detect the addition of new services, or the removal of services, the OSGi specifications have evolved beyond the original focus of service gateways, and are now used in applications ranging from mobile phones to the open-source Eclipse IDE. Other application areas include automobiles, industrial automation, building automation, PDAs, grid computing, entertainment, fleet management, the OSGi specification is developed by the members in an open process and made available to the public free of charge under the OSGi Specification License. The OSGi Alliance has a program that is open to members only. As of November 2010, there are seven certified OSGi framework implementations, a separate page lists both certified and non-certified OSGi Specification Implementations, which include OSGi frameworks and other OSGi specifications. OSGi is a Java framework for developing and deploying modular software programs, each bundle is a tightly coupled, dynamically loadable collection of classes, jars, and configuration files that explicitly declare their external dependencies. The framework is conceptually divided into the areas, Bundles Bundles are normal jar components with extra manifest headers. Services The services layer connects bundles in a way by offering a publish-find-bind model for Plain Old Java Interfaces or Plain Old Java Objects. Services Registry The application programming interface for management services, life-Cycle The application programming interface for life cycle management for bundles. Modules The layer that defines encapsulation and declaration of dependencies, security The layer that handles the security aspects by limiting bundle functionality to pre-defined capabilities. Execution Environment Defines what methods and classes are available in a specific platform, there is no fixed list of execution environments, since it is subject to change as the Java Community Process creates new versions and editions of Java. Bundle-SymbolicName, The only required header, this entry specifies an identifier for a bundle. Bundle-Description, A description of the bundles functionality, bundle-ManifestVersion, Indicates the OSGi specification to use for reading this bundle. Bundle-Version, Designates a version number to the bundle, bundle-Activator, Indicates the class name to be invoked once a bundle is activated. Export-Package, Expresses which Java packages contained in a bundle will be available to the outside world. Import-Package, Indicates which Java packages will be required from the world to fulfill the dependencies needed in a bundle. A Life Cycle layer adds bundles that can be installed, started, stopped, updated and uninstalled. Bundles rely on the layer for class loading but add an API to manage the modules in run time
6.
Jiro
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Jiro is the registered name used by Sun Microsystems for an extension to Java and Jini. Jiro was established by Sun in 1998 subsequent to acquiring a company called Redcape Policy Software. Initially known by the moniker StoreX, this technology was targeted at storage management, Jiro in many ways was a management oriented extension to Jini, leveraging many of Jinis ideas and capabilities for automatic detection of elements to be managed. Jiro was a Management Framework infrastructure based on a runtime environment. It was standardized as JSR9 by the Java Community Process, Jiro never gained the broad industry support necessary for success, because every device had to have a custom adapter, and it was withdrawn from the market in 2001. Mark Carlson led this effort based on his experience at Sun Microsystems as a Jiro developer, by 2005, most large storage systems providers had announced adoption of SNIAs SMI specifications within their storage management products. The SNIA has now embarked on a project to standardize Management Frameworks along the lines of the earlier Jiro project using web services to communicate between standard service components, Jiro Implements an infrastructure for creating integrated and automated management software in a distributed, cross-platform environment. Jiro makes use of Jini technology for allowing services come and go in network, Jiro introduces a middle tier of management between the client/GUI and other Java-based agent technologies such as JMX and JDMK. This middle tier is where the automation of management take place, Jiro divides a management environment into domains. Each domain only a shared management server that represents the domain as a whole, other private management server can host management services that are specific to their host
7.
Java Platform, Standard Edition
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Java Platform, Standard Edition or Java SE is a widely used computing platform for development and deployment of portable code for desktop and server environments. Java SE was formerly known as Java 2 Platform, Standard Edition or J2SE, the platform uses the object-oriented Java programming language. It is part of the Java software-platform family, Java SE defines a wide range of general-purpose APIs—such as Java APIs for the Java Class Library—and also includes the Java Language Specification and the Java Virtual Machine Specification. One of the most well-known implementations of Java SE is Oracle Corporations Java Development Kit. The platform was known as Java 2 Platform, Standard Edition or J2SE from version 1.2, until the name was changed to Java Platform, the SE is used to distinguish the base platform from the Enterprise Edition and Micro Edition platforms. The 2 was originally intended to emphasize the changes introduced in version 1.2. The naming convention has been changed several times over the Java version history, JSR59 was the umbrella specification for J2SE1.4 and JSR176 specified J2SE5.0. Java SE6 was released under JSR270, Java Platform, Enterprise Edition is a related specification that includes all the classes in Java SE, plus a number that are more useful to programs that run on servers as opposed to workstations. The Java Runtime Environment and Java Development Kit are the files downloaded and installed on a computer to run or develop Java programs. The Java package java. lang contains fundamental classes and interfaces closely tied to the language and this package contains 22 of 32 Error classes provided in JDK6. The main classes and interfaces in java. lang are, Object – the class that is the root of every class hierarchy, enum – the base class for enumeration classes. 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. Comparable – the interface that allows generic comparison and ordering of objects, iterable – the interface that allows generic iteration using the enhanced for loop. Math and StrictMath – classes that provide basic math such as sine, cosine. 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 and this package was added in J2SE1.2
8.
Data logger
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A data logger is an electronic device that records data over time or in relation to location either with a built in instrument or sensor or via external instruments and sensors. Increasingly, but not entirely, they are based on a digital processor and they generally are small, battery powered, portable, and equipped with a microprocessor, internal memory for data storage, and sensors. Data loggers vary between general purpose types for a range of measurement applications to specific devices for measuring in one environment or application type only. It is common for general purpose types to be programmable, however, electronic data loggers have replaced chart recorders in many applications. One of the benefits of using data loggers is the ability to automatically collect data on a 24-hour basis. Upon activation, data loggers are typically deployed and left unattended to measure and this allows for a comprehensive, accurate picture of the environmental conditions being monitored, such as air temperature and relative humidity. The cost of data loggers has been declining over the years as technology improves, simple single channel data loggers cost as little as $25. More complicated loggers may costs hundreds or thousands of dollars, standardisation of protocols and data formats has been a problem but is now growing in the industry and XML, JSON, and YAML are increasingly being adopted for data exchange. The development of the Semantic Web and the Internet of Things is likely to accelerate this present trend, several protocols have been standardised including a smart protocol, SDI-12, that allows some instrumentation to be connected to a variety of data loggers. The use of this standard has not gained much acceptance outside the environmental industry, SDI-12 also supports multi drop instruments. Some datalogging companies are now supporting the MODBUS standard. This has been used traditionally in the control area. Another multi drop protocol which is now starting to become widely used is based upon CAN Bus. Some data loggers use a flexible scripting environment to adapt themselves to various non-standard protocols, the terms data logging and data acquisition are often used interchangeably. However, in a context they are quite different. A data logger is a data system, but a data acquisition system is not necessarily a data logger. Data loggers typically have slower sample rates, a maximum sample rate of 1 Hz may be considered to be very fast for a data logger, yet very slow for a typical data acquisition system. Data loggers are implicitly stand-alone devices, while typical data acquisition system must remain tethered to a computer to acquire data and this stand-alone aspect of data loggers implies on-board memory that is used to store acquired data
9.
Java servlet
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A Java servlet is a Java program that extends the capabilities of a server. Although servlets can respond to any types of requests, they most commonly implement applications hosted on Web servers, such Web servlets are the Java counterpart to other dynamic Web content technologies such as PHP and ASP. NET. Servlets are most often used to process or store a Java class in Java EE that conforms to the Java Servlet API, servlets could in principle communicate over any client–server protocol, but they are most often used with the HTTP protocol. Thus servlet is often used as shorthand for HTTP servlet, thus, a software developer may use a servlet to add dynamic content to a web server using the Java platform. The generated content is commonly HTML, but may be other such as XML. Servlets can maintain state in session variables across many server transactions by using HTTP cookies, to deploy and run a servlet, a web container must be used. A web container is essentially the component of a web server that interacts with the servlets, the web container is responsible for managing the lifecycle of servlets, mapping a URL to a particular servlet and ensuring that the URL requester has the correct access rights. The Servlet API, contained in the Java package hierarchy javax. servlet, defines the interactions of the web container. A Servlet is an object receives a request and generates a response based on that request. The basic Servlet package defines Java objects to represent servlet requests and responses, as well as objects to reflect the servlets configuration parameters, servlets may be packaged in a WAR file as a web application. Servlets can be generated automatically from JavaServer Pages by the JavaServer Pages compiler, the difference between servlets and JSP is that servlets typically embed HTML inside Java code, while JSPs embed Java code in HTML. A somewhat older usage is to use servlets in conjunction with JSPs in a pattern called Model 2, the current version of Servlet is 3.1. The Servlet1 specification was created by Pavni Diwanji while she worked at Sun Microsystems, starting with version 2.3, the specification was developed under the Java Community Process. JSR53 defined both the Servlet 2.3 and JavaServer Page 1.2 specifications, JSR154 specifies the Servlet 2.4 and 2.5 specifications. As of June 9,2015, the current version of the Servlet specification is 3.1, in his blog on java. net, Sun veteran and GlassFish lead Jim Driscoll details the history of servlet technology. James Gosling first thought of servlets in the days of Java. This was before what is now the Java Platform, Enterprise Edition was made into a specification, the advantages of using servlets are their fast performance and ease of use combined with more power over traditional CGI. Traditional CGI scripts written in Java have a number of disadvantages, When an HTTP request is made
10.
JavaServer Pages
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JavaServer Pages is a technology that helps software developers create dynamically generated web pages based on HTML, XML, or other document types. Released in 1999 by Sun Microsystems, JSP is similar to PHP, ASP and Reacts JSX, to deploy and run JavaServer Pages, a compatible web server with a servlet container, such as Apache Tomcat or Jetty, is required. Architecturally, JSP may be viewed as an abstraction of Java servlets. JSPs are translated into servlets at runtime, therefore JSP is a Servlet, JSP can be used independently or as the view component of a server-side model–view–controller design, normally with JavaBeans as the model and Java servlets as the controller. This is a type of Model 2 architecture, the compiled pages, as well as any dependent Java libraries, contain Java bytecode rather than machine code. Like any other Java program, they must be executed within a Java virtual machine that interacts with the servers host operating system to provide an abstract, platform-neutral environment. JSPs are usually used to deliver HTML and XML documents, but through the use of OutputStream, the Web container creates JSP implicit objects like request, response, session, application, config, page, pageContext, out and exception. JSP Engine creates these objects during translation phase, JSP pages use several delimiters for scripting functions. %>, which encloses a JSP scriptlet, a scriptlet is a fragment of Java code that is run when the user requests the page. %> for expressions, where the scriptlet and delimiters are replaced with the result of evaluating the expression, Java code is not required to be complete or self-contained within a single scriptlet block. It can straddle markup content, provided that the page as a whole is syntactically correct, for example, any Java if/for/while blocks opened in one scriptlet must be correctly closed in a later scriptlet for the page to successfully compile. Content that falls inside a block of Java code is subject to that code. Content inside an if block will appear in the output when the if condition evaluates to true. Likewise, content inside a loop construct may appear multiple times in the output, the following would be a valid for loop in a JSP page, The output displayed in the users web browser would be, Counting to three, This number is 1. Version 2.0 of the JSP specification added support for the Expression Language, used to access data, in JSP2.1, it was folded into the Unified Expression Language, which is also used in JavaServer Faces. An example of EL Syntax, The value of variable in the object javabean is $, the JSP syntax add additional tags, called JSP actions, to invoke built-in functionality. Additionally, the technology allows for the creation of custom JSP tag libraries that act as extensions to the standard JSP syntax, some JSP containers support configuring how often the container checks JSP file timestamps to see whether the page has changed. Typically, this timestamp would be set to an interval during software development
11.
Java Web Start
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In computing, Java Web Start is a framework developed by Sun Microsystems that allows users to start application software for the Java Platform directly from the Internet using a web browser. Some key benefits of this technology include seamless version updating for globally distributed applications, unlike Java applets, Web Start applications do not run inside the browser. By default they run in the sandbox as applets, with several minor extensions like allowing to load. Only signed applications can be configured to have additional permissions, Web Start has an advantage over applets in that it overcomes many compatibility problems with browsers Java plugins and different JVM versions. Web Start programs are no longer a part of the web page. Web Start can also launch unmodified applets that are packaged inside. jar files and this file can also pass the applet parameters. Such applets also run in a separate frame, applet launcher may not support some specific cases like loading class as resource. Like applets, Java Web Start is cross-platform, the developer prepares a special XML file with JNLP extension. This file describes the requirements, code location, parameters. The browser downloads this file as any other and opens it with Web Start tool, Web Start tool downloads all necessary resources and launches the application. Java Web Start provides a series of classes in the javax. jnlp package which provide services to the application. Sun designed most of these services with the aim of allowing carefully controlled access to resources while restricting the application to authorized operations, Sun introduced version 1.0 of Web Start in March 2001, while 64-bit Windows support was added only in Java 6. Since J2SE1.4 Web Start comes as a part of Java Runtime Environment called javaws. Programmers often speak of the Java Network Launching Protocol interchangeably with the term Web Start, the JNLP protocol, defined with an XML schema, specifies how to launch Java Web Start applications. JNLP consists of a set of defining how exactly to implement the launching mechanism. JNLP files include information such as the location of the jar package file, a properly configured browser passes JNLP files to a Java Runtime Environment which in turn downloads the application onto the users machine and starts executing it. The development of JNLP took place under the Java Community Process as JSR56 and it includes the original 1.0 release, the subsequent 1.5 maintenance release, and as of 2006, the pending 6.0 maintenance release. The user does not have to remain connected to the Internet to execute the downloaded programs, updates of the software download from the Web and become available when the user has a connection to the Internet, thus easing the burden of deployment
12.
Java Platform, Micro Edition
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Java Platform, Micro Edition or Java ME is a computing platform for development and deployment of portable code for embedded and mobile devices. Java ME was formerly known as Java 2 Platform, Micro Edition or J2ME, the platform uses the object-oriented Java programming language. It is part of the Java software-platform family, Java ME was designed by Sun Microsystems, acquired by Oracle Corporation in 2010, the platform replaced a similar technology, PersonalJava. Originally developed under the Java Community Process as JSR68, the different flavors of Java ME have evolved in separate JSRs, as of 22 December 2006, the Java ME source code is licensed under the GNU General Public License, and is released under the project name phoneME. As of 2008, all Java ME platforms are currently restricted to JRE1.3 features, Java ME devices implement a profile. Profiles are subsets of configurations, of which there are two, the Connected Limited Device Configuration and the Connected Device Configuration. There are more than 2.1 billion Java ME enabled mobile phones and it is popular in sub $200 devices such as Nokias Series 40. It was also used on the Bada operating system and on Symbian OS along with native software, users of Windows CE, Windows Mobile, Maemo, MeeGo and Android can download Java ME for their respective environments. The Connected Limited Device Configuration contains a subset of the Java-class libraries. CLDC is basically used for classifying myriad devices into a fixed configuration, a configuration provides the most basic set of libraries and virtual-machine features that must be present in each implementation of a J2ME environment. When coupled with one or more profiles, the Connected Limited Device Configuration gives developers a solid Java platform for creating applications for consumer and embedded devices. The configuration is designed for devices with 160KB to 512KB total memory, designed for mobile phones, the Mobile Information Device Profile includes a GUI, and a data storage API, and MIDP2.0 includes a basic 2D gaming API. Applications written for this profile are called MIDlets, almost all new cell phones come with a MIDP implementation, and it is now the de facto standard for downloadable cell phone games. However, many cellphones can run only those MIDlets that have approved by the carrier. A key design goal of MIDP3 is backward compatibility with MIDP2 content, the Connected Device Configuration is a subset of Java SE, containing almost all the libraries that are not GUI related. The Foundation Profile is a Java ME Connected Device Configuration profile and this profile is intended to be used by devices requiring a complete implementation of the Java virtual machine up to and including the entire Java Platform, Standard Edition API. Typical implementations will use some subset of that API set depending on the additional profiles supported and this specification was developed under the Java Community Process. The Personal Basis Profile extends the Foundation Profile to include lightweight GUI support in the form of an AWT subset and this is the platform that BD-J is built upon
13.
USB
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It is currently developed by the USB Implementers Forum. USB was designed to standardize the connection of peripherals to personal computers. It has become commonplace on other devices, such as smartphones, PDAs, USB has effectively replaced a variety of earlier interfaces, such as serial ports and parallel ports, as well as separate power chargers for portable devices. Also, there are 5 modes of USB data transfer, in order of increasing bandwidth, Low Speed, Full Speed, High Speed, SuperSpeed, USB devices have some choice of implemented modes, and USB version is not a reliable statement of implemented modes. Modes are identified by their names and icons, and the specifications suggests that plugs, unlike other data buses, USB connections are directed, with both upstream and downstream ports emanating from a single host. This applies to power, with only downstream facing ports providing power. Thus, USB cables have different ends, A and B, therefore, in general, each different format requires four different connectors, a plug and receptacle for each of the A and B ends. USB cables have the plugs, and the corresponding receptacles are on the computers or electronic devices, in common practice, the A end is usually the standard format, and the B side varies over standard, mini, and micro. The mini and micro formats also provide for USB On-The-Go with a hermaphroditic AB receptacle, the micro format is the most durable from the point of view of designed insertion lifetime. The standard and mini connectors have a lifetime of 1,500 insertion-removal cycles. Likewise, the component of the retention mechanism, parts that provide required gripping force, were also moved into plugs on the cable side. A group of seven companies began the development of USB in 1994, Compaq, DEC, IBM, Intel, Microsoft, NEC, a team including Ajay Bhatt worked on the standard at Intel, the first integrated circuits supporting USB were produced by Intel in 1995. The original USB1.0 specification, which was introduced in January 1996, Microsoft Windows 95, OSR2.1 provided OEM support for the devices. The first widely used version of USB was 1.1, the 12 Mbit/s data rate was intended for higher-speed devices such as disk drives, and the lower 1.5 Mbit/s rate for low data rate devices such as joysticks. Apple Inc. s iMac was the first mainstream product with USB, following Apples design decision to remove all legacy ports from the iMac, many PC manufacturers began building legacy-free PCs, which led to the broader PC market using USB as a standard. The USB2.0 specification was released in April 2000 and was ratified by the USB Implementers Forum at the end of 2001.1 specification, the USB3.0 specification was published on 12 November 2008. Its main goals were to increase the transfer rate, decrease power consumption, increase power output. USB3.0 includes a new, higher speed bus called SuperSpeed in parallel with the USB2.0 bus, for this reason, the new version is also called SuperSpeed
14.
Web Services Description Language
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The Web Services Description Language is an XML-based interface definition language that is used for describing the functionality offered by a web service. Therefore, its purpose is similar to that of a method signature in a programming language. The current version of WSDL is WSDL2.0, the meaning of the acronym has changed from version 1.1 where the D stood for Definition. The WSDL describes services as collections of network endpoints, or ports, the WSDL specification provides an XML format for documents for this purpose. The abstract definitions of ports and messages are separated from their use or instance. A port is defined by associating a network address with a binding. Messages are abstract descriptions of the data being exchanged, and port types are abstract collections of supported operations, in this way, WSDL describes the public interface to the Web service. WSDL is often used in combination with SOAP and an XML Schema to provide Web services over the Internet, a client program connecting to a Web service can read the WSDL file to determine what operations are available on the server. Any special datatypes used are embedded in the WSDL file in the form of XML Schema, the client can then use SOAP to actually call one of the operations listed in the WSDL file using for example XML over HTTP. The current version of the specification is 2.0, version 1.1 has not been endorsed by the W3C, WSDL1.2 was renamed WSDL2.0 because of its substantial differences from WSDL1.1. By accepting binding to all the HTTP request methods, the WSDL2.0 specification offers better support for RESTful web services, however support for this specification is still poor in software development kits for Web Services which often offer tools only for WSDL1.1. For example, the version 2.0 of the Business Process Execution Language only supports WSDL1.1, Subset WSDL is a WSDL with the subset operations of an original WSDL. A developer can use SWSDL to access Subset Service, thus handle subset of web service code, a Subset WSDL can be used to perform web service testing and top down development. Slicing of a web service can be using a Subset WSDL to access Subset Service. Subset Service can be categorized into layers using SWSDL, SWSDLs are used for Web service analysis, testing and top down development. AWSCM is the tool to construct SWSDLs successfully. WSDL1.0 was developed by IBM, Microsoft, and it was built by combining two service description languages, NASSL from IBM and SDL from Microsoft. WSDL1.1, published in March 2001, is the formalization of WSDL1.0, no major changes were introduced between 1.0 and 1.1
15.
JavaServer Faces
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JavaServer Faces is a Java specification for building component-based user interfaces for web applications. It was formalized as a standard through the Java Community Process and is part of the Java Platform, JSF2 uses Facelets as its default templating system. Other view technologies such as XUL or plain Java can also be employed, in contrast, JSF1. x uses JavaServer Pages as its default templating system. JSF2.3 – Major features, search Expressions, extensionless URLs, bean validation for complete classes, push communication using WebSocket, JSF2.2 – Introduced new concepts like stateless views, page flow and the ability to create portable resource contracts. JSF2.1 – Maintenance release 2 of JSF2.0, only a very minor number of specification changes. JSF2.0 – Major release for ease of use, enhanced functionality, JSF1.2 – Many improvements to core systems and APIs. JSF1.0 – Initial specification released, based on a component-driven UI design-model, JavaServer Faces uses XML files called view templates or Facelets views. The FacesServlet processes requests, loads the appropriate view template, builds a component tree, processes events, and renders the response to the client. The state of UI components and other objects of scope interest is saved at the end of each request in a process called stateSaving, either the client or the server side can save objects and states. JSF is often used together with Ajax, a Rich Internet application technology, Ajax is a combination of technologies that make it possible to create rich user interfaces. The user interface components in Mojarra and Apache MyFaces were originally developed for HTML only and this has changed, however, Because JSF supports multiple output formats, Ajax-enabled components can easily be added to enrich JSF-based user interfaces. JSF2 includes support for graceful degradation when JavaScript is disabled in the browser and it reached its end-of-life in June 2016.0. This eliminates the life-cycle conflicts that existed with JSP, forcing workarounds by Java developers, Facelets allows easy component/tag creation using XML markup instead of Java code, the chief complaint against JSF1. x. Navigation has been simplified, removing the need for faces-config. xml navigation cases, page transitions can be invoked simply by passing the name of the desired View/Facelet. Addition of Partial State Saving and DOM updates are part of the built in standardized Ajax support, includes logical naming and versioning of resources. In their January 2014 Technology Radar publication, ThoughtWorks wrote, We continue to see teams run into trouble using JSF -- JavaServer Faces -- and are recommending you avoid this technology. Teams seem to choose JSF because it is a JEE standard without really evaluating whether the programming model suits them and we think JSF is flawed because it tries to abstract away HTML, CSS and HTTP, exactly the reverse of what modern web frameworks do. JSF, like ASP. NET webforms, attempts to create statefulness on top of the stateless protocol HTTP and we are aware of the improvements in JSF2.0, but think the model is fundamentally broken
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