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57-519: Although both JSP and Faces technologies have been improved to work better together, Facelets eliminates the issues noted in Hans Bergsten 's article "Improving JSF by Dumping JSP" Facelets draws on some of the ideas from Apache Tapestry , and is similar enough to draw comparison. The project is conceptually similar to Tapestry's, which treats blocks of HTML elements as framework components backed by Java classes. Facelets also has some similarities to

114-559: A Java virtual machine (JVM) that interacts with the server's 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, they can deliver other types of data as well. 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. JSPs use several delimiters for scripting functions. The most basic

171-528: A Facelet in a taglib file. Occurrences of that tag will then be replaced with the content of the associated Facelet. The following shows an example of this: templates/master_template.xhtml The code above uses the tag <my:spacer> to mark the point in the Facelet where content is to be inserted. Such a tag has to be declared in a Taglib file where it can be associated with a Facelet as follows: example.taglib.xml The following shows an example of what

228-417: A compatible web server with a servlet container , such as Apache Tomcat or Jetty , is required. Architecturally, JSP may be viewed as a high-level abstraction of Jakarta Servlets . JSPs are translated into servlets at runtime, therefore JSP is a Servlet; each JSP servlet is cached and re-used until the original JSP is modified. Jakarta Server Pages can be used independently or as the view component of

285-412: A deadline. Software analysis begins with a requirements analysis to capture the business needs of the software. Challenges for the identification of needs are that current or potential users may have different and incompatible needs, may not understand their own needs, and change their needs during the process of software development. Ultimately, the result of analysis is a detailed specification for

342-484: A default HTML 'frame' and a single placeholder called body_content . A template client can use this template as follows: template_client.xhtml The above code makes use of the template /templates/master_template.xhtml and provides content for the placeholder in that template. The final result will be a page called template_client.xhtml that has the content of /templates/master_template.xhtml , but with <ui:insert name="body_content"/> replaced by 'This

399-483: A facility for templating. A Facelets file can reference a master template and provide content for the placeholders this master template defines. The file that references such a template is called the template client . Template clients themselves can again be used as a template for other template clients and as such a hierarchy of templates can be created. The following shows an example of a simple master template: templates/master_template.xhtml The above code contains

456-401: A legacy fall back. In Facelets, templates tags from a tag library can be entered in two forms: directly as a qualified xml element or indirectly via the jsfc attribute on an arbitrary non-qualified element. In the latter case the Facelet compiler will ignore the actual element and will process the element as if it was the one given by the jsfc attribute. The following example shows

513-564: A longer interval (perhaps minutes, or even never) for a deployed Web application . According to Joel Murach and Michael Urban, authors of the book "Murach's Java Servlets and JSP", embedding Java code in JSP is generally bad practice. A better approach would be to migrate the back-end logic embedded in the JSP to the Java code in the Servlet . In this scenario, the Servlet is responsible for processing, and

570-420: A note to his site saying that JSP had improved since 2000, but also cited its competitors, Apache Velocity and Tea (template language). Today, several alternatives and a number of JSP-oriented pages in larger web apps are considered to be technical debt. Software developer Software development is the process of designing and implementing a software solution to satisfy a user . The process

627-581: A server-side model–view–controller design, normally with JavaBeans as the model and Java servlets (or a framework such as Apache Struts ) as the controller. This is a type of Model 2 architecture. JSP allows Java code and certain predefined actions to be interleaved with static web markup content, such as HTML. The resulting page is compiled and executed on the server to deliver a document. The compiled pages, as well as any dependent Java libraries, contain Java bytecode rather than machine code . Like any other .jar or Java program, code must be executed within

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684-437: 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. This allows code to be intermingled and can result in poor programming practices. Content that falls inside a split block of Java code (spanning multiple scriptlets)

741-604: A tag name. The namespace is constructed of the fixed string ' http://java.sun.com/jsf/composite/' concatenated with the directory name in which the content file resides relative to the 'resources' directory. The tag name becomes the file name without the .xhtml suffix. The following shows an example of this: resources/my/spacer.xhtml The above Facelet is automatically available as a component in namespace 'http://java.sun.com/jsf/composite/my' and tag name 'spacer' To customize included content, Facelets allows parameters to be used. Via those parameters, objects can be passed into

798-446: Is <% ... %> , which encloses a JSP scriptlet. A scriptlet is a fragment of Java code that runs when the user requests the page. Other common delimiters include <%= ... %> for expressions, where the scriptlet and delimiters are replaced with the result of evaluating the expression, and directives , denoted with <%@ ... %> . Java code is not required to be complete or self-contained within

855-511: Is a framework that provides the viewpoints on the system and its environment , to be used in the software development process . It is a graphical representation of the underlying semantics of a view. The purpose of viewpoints and views is to enable human engineers to comprehend very complex systems and to organize the elements of the problem around domains of expertise . In the engineering of physically intensive systems, viewpoints often correspond to capabilities and responsibilities within

912-408: Is a popular way of managing changes made to the software. Whenever a new version is checked in, the software saves a backup of all modified files. If multiple programmers are working on the software simultaneously, it manages the merging of their code changes. The software highlights cases where there is a conflict between two sets of changes and allows programmers to fix the conflict. A view model

969-406: Is a template client page that uses the master template.'. In addition to templating, Facelets provides support for re-use by letting the user include content that resides in a different file. Including such content can be done in three different ways: The simplest way to include the content of another Facelet is referencing it by name using the <ui:include> tag. This causes the content in

1026-449: Is correctly incorporated with the newer software. Design involves choices about the implementation of the software, such as which programming languages and database software to use, or how the hardware and network communications will be organized. Design may be iterative with users consulted about their needs in a process of trial and error . Design often involves people expert in aspect such as database design , screen architecture, and

1083-833: Is essential to success. This is more easily achieved if the team is small, used to working together, and located near each other. Communications also help identify problems at an earlier state of development and avoid duplicated effort. Many development projects avoid the risk of losing essential knowledge held by only one employee by ensuring that multiple workers are familiar with each component. Software development involves professionals from various fields, not just software programmers but also individuals specialized in testing, documentation writing, graphic design , user support, marketing , and fundraising. Although workers for proprietary software are paid, most contributors to open-source software are volunteers. Alternately, they may be paid by companies whose business model does not involve selling

1140-399: Is helpful for new developers to understand the project when they begin working on it. In agile development, the documentation is often written at the same time as the code. User documentation is more frequently written by technical writers . Accurate estimation is crucial at the feasibility stage and in delivering the product on time and within budget. The process of generating estimations

1197-422: Is inefficient, difficult to understand, or lacking documentation on its functionality. These standards are especially likely to break down in the presence of deadlines. As a result, testing, debugging, and revising the code becomes much more difficult. Code refactoring , for example adding more comments to the code, is a solution to improve the understandability of code. Testing is the process of ensuring that

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1254-744: Is more encompassing than programming , writing code , in that it includes conceiving the goal, evaluating feasibility, analyzing requirements , design , testing and release . The process is part of software engineering which also includes organizational management , project management , configuration management and other aspects. Software development involves many skills and job specializations including programming , testing , documentation , graphic design , user support , marketing , and fundraising . Software development involves many tools including: compiler , integrated development environment (IDE), version control , computer-aided software engineering , and word processor . The details of

1311-440: Is often delegated by the project manager . Because the effort estimation is directly related to the size of the complete application, it is strongly influenced by addition of features in the requirements—the more requirements, the higher the development cost. Aspects not related to functionality, such as the experience of the software developers and code reusability, are also essential to consider in estimation. As of 2019 , most of

1368-432: Is often used to break down the customer's requirements into pieces that can be implemented by software programmers. The underlying logic of the program may be represented in data-flow diagrams , data dictionaries , pseudocode , state transition diagrams , and/or entity relationship diagrams . If the project incorporates a piece of legacy software that has not been modeled, this software may be modeled to help ensure it

1425-401: Is robust to heavy levels of input or usage), integration testing (to ensure that the software is adequately integrated with other software), and compatibility testing (measuring the software's performance across different operating systems or browsers). When tests are written before the code, this is called test-driven development . Production is the phase in which software is deployed to

1482-412: Is subject to that code. Content inside an if block will only appear in the output when the if condition evaluates to true. Likewise, content inside a loop construct may appear multiple times in the output, depending upon how many times the loop body runs. The following would be a valid for loop in a JSP page: The output displayed in the user's web browser would be: The JSP useBean tag enables

1539-661: Is the JSTL . Jakarta Standard Tag Library (JSTL) supports common tasks that must be performed in JSPs. Examples includes iteration and conditionals (the equivalent of "for" and "if" statements in Java). Out of all the libraries in JSTL, the JSTL core library is most commonly used. A taglib directive must be used to specify the URI of the JSTL core library using a prefix. Although there are many different choices for

1596-431: Is then written between the opening and closing braces. The following is an example of EL syntax : The value of variable in the object javabean is $ {javabean.variable} . 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. One such library

1653-530: The Apache Tiles framework with respect to support templating as well as composition. Facelets was originally created by Jacob Hookom in 2005 as a separate, alternative view declaration language for JSF 1.1 and JSF 1.2 which both used JSP as the default view declaration language. Starting from JSF 2.0, Facelets has been promoted by the JSF expert group to be the default view declaration language. JSP has been deprecated as

1710-471: The programming language ). Documentation comes in two forms that are usually kept separate—that intended for software developers, and that made available to the end user to help them use the software. Most developer documentation is in the form of code comments for each file, class , and method that cover the application programming interface (API)—how the piece of software can be accessed by another—and often implementation details. This documentation

1767-544: The JSP is responsible for displaying the HTML, maintaining a clear separation of concerns . In 2000, Jason Hunter, author of "Java Servlet Programming" described a number of "problems" with JavaServer Pages. Nevertheless, he wrote that while JSP may not be the "best solution for the Java Platform" it was the "Java solution that is most like the non-Java solution," by which he meant Microsoft's Active Server Pages . Later, he added

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1824-403: The actual content Facelet could look like: spacer.xhtml Besides including content directly, Facelets provides the composite component mechanism that makes content available as a first-class JSF component. Composite components do not need to be declared in a Taglib file, but instead have to be put in a special directory. By convention the content is then automatically assigned a namespace and

1881-489: The available methodologies are best suited to specific kinds of projects, based on various technical, organizational, project, and team considerations. Another focus in many programming methodologies is the idea of trying to catch issues such as security vulnerabilities and bugs as early as possible ( shift-left testing ) to reduce the cost of tracking and fixing them. In 2009, it was estimated that 32 percent of software projects were delivered on time and budget, and with

1938-410: The bean. The scope declares the object responsible for storing the bean. The value for the scope defines the duration for which the bean is available for the rest of the java application to use. The scope can be one of the following four values: After a bean has been created using the useBean tag, the getProperty and setProperty tags can be used for getting and setting the properties of

1995-553: The bean. The JSP getProperty is used to get the property of created bean. The JSP setProperty tag is used to set the properties for a bean. For the getProperty and setProperty tags, the name attribute is used to specify the bean's name. So the name attribute must match the id attribute provided by the useBean tag. Version 2.0 of the JSP specification added support for the Expression Language (EL), used to access data and functions in Java objects. In JSP 2.1, it

2052-423: The code executes correctly and without errors. Debugging is performed by each software developer on their own code to confirm that the code does what it is intended to. In particular, it is crucial that the software executes on all inputs, even if the result is incorrect. Code reviews by other developers are often used to scrutinize new code added to the project, and according to some estimates dramatically reduce

2109-442: The common <%@ page .. %> directive may instead be written as a <jsp:directive.page .. /> tag, and tag libraries are imported using XML namespaces , instead of the usual <%@ taglib .. %> tag. A JavaServer Pages compiler is a program that parses JSPs and transforms them into executable Java Servlets . A program of this type is usually embedded into the application server and run automatically

2166-419: The developer to access and create a Javabean. Although using the useBean tag looks similar to an HTML tag, all JSP tags for JavaBeans use XML syntax. Therefore the code containing the useBean tag is case-sensitive. The useBean tag contains several attributes. The id attribute declares the name that is used for gaining access to the bean. The class attribute declares the package and class for

2223-459: The direct usage of qualified tags: Using the jsfc attribute, the same code can also be expressed as the example given below: The above code can be viewed in a browser, and edited with conventional WYSIWYG design tools. This is not possible when directly using the qualified tags. Nevertheless, directly using qualified tags is the most popular way of using Facelets in practice and is the style most used in books and examples. Facelets provides

2280-408: The end user. During production, the developer may create technical support resources for users or a process for fixing bugs and errors that were not caught earlier. There might also be a return to earlier development phases if user needs changed or were misunderstood. Software development is performed by software developers , usually working on a team. Efficient communications between team members

2337-430: The engineering organization. Fitness functions are automated and objective tests to ensure that the new developments don't deviate from the established constraints, checks and compliance controls. Intellectual property can be an issue when developers integrate open-source code or libraries into a proprietary product, because most open-source licenses used for software require that modifications be released under

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2394-401: The first time a JSP is accessed, but pages may also be precompiled for better performance, or compiled as a part of the build process to test for errors. 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 a short interval (perhaps seconds) during software development , and

2451-477: The full functionality. An additional 44 percent were delivered, but missing at least one of these features. The remaining 24 percent were cancelled prior to release. Software development life cycle refers to the systematic process of developing applications . The sources of ideas for software products are plentiful. These ideas can come from market research including the demographics of potential new customers, existing customers, sales prospects who rejected

2508-449: The included content, where they can be used as variables. For the <ui:include> mechanism the <ui:param> can be used for this, while for the custom tags and composite components, normal tag attributes can be used. Composite components require parameters to be declared in their interface section, while for custom tags there is no such requirement and values provided for arbitrary attributes are made available as variables with

2565-407: The number of bugs persisting after testing is complete. Once the code has been submitted, quality assurance —a separate department of non-programmers for most large companies—test the accuracy of the entire software product. Acceptance tests derived from the original software requirements are a popular tool for this. Quality testing also often includes stress and load checking (whether the software

2622-403: The performance of servers and other hardware. Designers often attempt to find patterns in the software's functionality to spin off distinct modules that can be reused with object-oriented programming . An example of this is the model–view–controller , an interface between a graphical user interface and the backend . The central feature of software development is creating and understanding

2679-453: The prefix, the "c" prefix is commonly used for this library. JSP pages may also be written in fully valid XML syntax. Such JSP files commonly use the alternative .jspx file extension, which usually causes the application server to validate the XML syntax. Since the usual JSP syntax <% ... %> is not valid in XML, a developer must use alternative tags provided by JSP. For example,

2736-463: The process used for a development effort varies. The process may be confined to a formal, documented standard , or it can be customized and emergent for the development effort. The process may be sequential, in which each major phase (i.e. design, implement and test) is completed before the next begins, but an iterative approach – where small aspects are separately designed, implemented and tested – can reduce risk and cost and increase quality. Each of

2793-424: The product that developers can work from. Software analysts often decompose the project into smaller objects, components that can be reused for increased cost-effectiveness, efficiency, and reliability. Decomposing the project may enable a multi-threaded implementation that runs significantly faster on multiprocessor computers. During the analysis and design phases of software development, structured analysis

2850-466: The product, other internal software development staff, or a creative third party. Ideas for software products are usually first evaluated by marketing personnel for economic feasibility, fit with existing channels of distribution, possible effects on existing product lines, required features , and fit with the company's marketing objectives. In the marketing evaluation phase, the cost and time assumptions become evaluated. The feasibility analysis estimates

2907-503: The project's return on investment , its development cost and timeframe. Based on this analysis, the company can make a business decision to invest in further development. After deciding to develop the software, the company is focused on delivering the product at or below the estimated cost and time, and with a high standard of quality (i.e., lack of bugs) and the desired functionality. Nevertheless, most software projects run late and sometimes compromises are made in features or quality to meet

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2964-462: The referenced file to be directly included in the calling Facelet by the Facelets compiler. Besides re-using content at multiple locations, this can be used to break down a large Facelet into smaller parts. The following shows an example: templates/master_template.xhtml html_head.xhtml Facelets supports indirection for including content via custom tags. Such a custom tag can be associated with

3021-495: The same name as said attribute. Jakarta Server Pages Jakarta Server Pages ( JSP ; formerly JavaServer Pages ) is a collection of technologies that helps software developers create dynamically generated web pages based on HTML , XML , SOAP , or other document types. Released in 1999 by Sun Microsystems , JSP is similar to PHP and ASP , but uses the Java programming language . To deploy and run Jakarta Server Pages,

3078-427: The software that implements the desired functionality. There are various strategies for writing the code. Cohesive software has various components that are independent from each other. Coupling is the interrelation of different software components, which is viewed as undesirable because it increases the difficulty of maintenance . Often, software programmers do not follow industry best practices, resulting in code that

3135-403: The software, but something else—such as services and modifications to open source software. Computer-aided software engineering (CASE) is tools for the partial automation of software development. CASE enables designers to sketch out the logic of a program, whether one to be written, or an already existing one to help integrate it with new code or reverse engineer it (for example, to change

3192-520: The tools for estimating the amount of time and resources for software development were designed for conventional applications and are not applicable to web applications or mobile applications . An integrated development environment (IDE) supports software development with enhanced features compared to a simple text editor . IDEs often include automated compiling , syntax highlighting of errors, debugging assistance, integration with version control , and semi-automation of tests. Version control

3249-550: Was folded into the Unified Expression Language , which is also used in JavaServer Faces . The JSP Expression Language uses a compact syntax which enables the developer to get attributes and JavaBean properties from a given request object. When using EL, a dollar sign ("$ ") must be added at the beginning of the code. The dollar symbol is followed by an opening brace ("{"), as well as a closing brace ("}"). The code

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