Developing standardized web portals in java with the Liferay system

摘要

In recent years, there is a growing number of web portals that enable the management of online content and documents. These are so called web content management systems(WCMS). WCMS systems are today developed for the most software platforms such as. . NET, PHP, Python and Java. . NET is a software framework that is accessible on most Microsoft Windows operating systems and is used to make applications for the Microsoft Windows platform. PHP Scripting Language is designed for generating dynamic web pages. Python and Java are for general purposes programming languages, which can be used on most of today's operating systems. The need for standardization of software development are derived primarily from reducing costs, interchangeability of components, increased interoperability and increased safety. An example of such WCMS system is a portal Liferay. Portal contains the implementation of many Java specifications. Examples of such specifications are specifications: Java portlet JSR-168, JavaServer Faces JSR-127, Java content repository JSR-170. These specifications form the basis for the construction of the standard Java portals, portlets and systems for content management. Liferay Portal allows users to generate advanced high-performance web sites through which it is possible to manage online communities, dynamically generated web pages, manage and version content, etc. Advanced architecture and use of generated content caching enables Liferay portal to be one of the high performance portals. Content caching is on the other hand, reflected in higher consumption of random access memory compared to WCMS systems written in the programming language PHP. A representative of such a system is WCMS portal Joomla, which uses MySQL database to store data and is fairly widespread among the users WCMS systems primarily because of its easy use and easy installation. The increased use of working memory in the Liferay portal is mainly becouse of use of caching and the use of Java technology, which on the other hand allows the advanced architecture and the processing of a significantly more number of requests per unit time according to comparable systems WCMS Joomla. Java portlet specification JSR-168 implementation allows generation of web pages that contain a number of mutually independent components called portlets. Each portlet generates part of the contents of the website. That part of the contents is called a fragment. The entire portal page is composed of individual fragments, which are aggregated and as such represent one web page of portal. JavaServer Faces specification JSR-127 implementation allows developers to implement web applications with components of the abstract programming model, which almost completely avoids specificity of Hyper Text Markup Language. Java content repository specification JSR-170 and its upgrade JSR-283 allow developers to build content repositorys. Content repository is a hierarchical tree structure through which you can be store, edit, version and perform many other actions over the content stored in the content repository. In this graduate work I will accurately describe these Java specifications, the capacity of Liferay Portal and show their use in the implementation of Portlet within Liferay Portal. ududud