Java Application Server Interview Questions And Answers - DoAnswers.com

Following the success of the Java platform, the term application server sometimes refers to a J2EE or Java EE 5 application server. Among the better known Java Enterprise Edition application servers are WebLogic Server (BEA), JBoss (Red Hat), WebSphere Application Server and WebSphere Application Server Community Edition (IBM), JRun (Adobe), Apache Geronimo (Apache Software Foundation), Oracle OC4J (Oracle Corporation), Sun Java System Application Server (Sun Microsystems), SAP Web Application Server and Glassfish Application Server (based on Sun Java System Application Server).

JOnAS application server was the first open source application server to have achieved official compliance with the Java Enterprise Specification. BEA delivered the first Java EE 5 certified application server followed by Sun Microsystems' reference implementation GlassFish.

The Web modules are servlets and JavaServer Pages, and business logic is built into Enterprise JavaBeans (EJB-3 and later). The Hibernate project offers an EJB-3 container implementation for the JBoss Application server. Tomcat from Apache and JOnAS from ObjectWeb are typical of containers into which these modules can be put.

A Java Server Page (JSP) is a servlet from Java that executes in a Web container�the Java equivalent of CGI scripts. JSPs are a way to create HTML pages by embedding References to the server logic within the page. HTML coders and Java programmers can work side by side by referencing each other's code from within their own. JavaBeans are the independent class components of the Java architecture from Sun Microsystems.

The application servers mentioned above mainly serve Web applications. Some application servers target networks other than the Web: Session Initiation Protocol servers, for instance, target telephony networks.

Tomcat Application Server Interview Questions And Answers

Apache Tomcat is a Servlet container developed by the Apache Software Foundation (ASF). Tomcat implements the Java Servlet and the JavaServer Pages (JSP) specifications from Sun Microsystems, and provides a "pure Java" HTTP web server environment for Java code to run.

Tomcat should not be confused with the Apache web server, which is a C implementation of a HTTP web server; these two HTTP web servers are not bundled together. Apache Tomcat includes tools for configuration and management, but can also be configured by editing configuration files that are normally XML-formatted.

WebLogic Application Server Interview Questions And Answers

BEA Systems' WebLogic is a server software application that runs on a middle tier, between back-end databases and related applications and browser-based thin clients. WebLogic is a leading e-commerce online transaction processing (OLTP) platform, developed to connect users in a distributed computing environment and to facilitate the integration of mainframe applications with distributed corporate data and applications.

WebLogic server is based on Java 2 Platform, Enterprise Edition (J2EE), the standard platform used to create Java-based multi-tier enterprise applications. J2EE platform technologies were developed through the efforts of BEA Systems and other vendors in collaboration with the main developer, Sun Microsystems. Because J2EE applications are standardized modules, WebLogic can automate many system-level tasks that would otherwise have demanded programming time.

The main features of WebLogic server include connectors that make it possible for any legacy application on any client to interoperate with server applications, Enterprise JavaBean (EJB) components, resource pooling, and connection sharing that make applications very scalable. An administration console with a user interface makes management tasks more efficient and features such as Secure Sockets Layer (SSL) support for the encryption of data transmissions, as well as authentication and authorization mechanisms, make applications and transactions secure.