J2EE Interview Questions

If you're looking for J2EE Interview Questions for Experienced or Freshers, you are at right place. There are lot of opportunities from many reputed companies in the world. According to research J2EE has a market share of about 7.0%. So, You still have opportunity to move ahead in your career in J2EE Development. Mindmajix offers Advanced J2EE Interview Questions 2018 that helps you in cracking your interview & acquire dream career as J2EE Developer.

Q. What is the Java 2 Platform Enterprise Edition (J2EE)?
The Java 2 Platform Enterprise Edition (J2EE) is a set of coordinated specifications and practices that together enable solutions for developing, deploying, and managing multi-tier server-centric applications. Building on the Java 2 Platform, Standard Edition (J2SE), the J2EE platform adds the capabilities necessary to provide a complete, stable, secure, and fast Java platform to the enterprise level. It provides value by significantly reducing the cost and complexity of developing and deploying multi-tier solutions, resulting in services that can be rapidly deployed and easily enhanced.

Q. What are the main benefits of the J2EE platform?
The J2EE platform provides the following:

** Complete Web services support. The J2EE platform provides a framework for developing and deploying web services on the Java platform. The Java API for XML-based RPC (JAX-RPC) enables Java technology developers to develop SOAP based interoperable and portable web services. Developers use the standard JAX-RPC programming model to develop SOAP based web service clients and endpoints. A web service endpoint is described using a Web Services Description Language (WSDL) document. JAX-RPC enables JAX-RPC clients to invoke web services developed across heterogeneous platforms. In a similar manner, JAX-RPC web service endpoints can be invoked by heterogeneous clients. For more info, see HTTP://JAVA.SUN.COM/WEBSERVICES/.

** It provides faster solutions delivery time to market. The J2EE platform uses containers to simplify development. J2EE containers provide for the separation of business logic from resource and lifecycle management, which means that developers can focus on writing business logic — their value add — rather than writing enterprise infrastructure. For example, the Enterprise JavaBeans (EJB) container (implemented by J2EE technology vendors) handles distributed communication, threading, scaling, transaction management, etc. Similarly, Java Servlets simplify web development by providing infrastructure for component, communication, and session management in a web container that is integrated with a web server.

** It provides freedom of choice. J2EE technology is a set of standards that many vendors can implement. The vendors are free to compete on implementations but not on standards or APIs. Sun supplies a comprehensive J2EE Compatibility Test Suite (CTS) to J2EE licensees. The J2EE CTS helps ensure compatibility among the application vendors which helps ensure portability for the applications and components written for the J2EE platform. The J2EE platform brings Write Once, Run Anywhere (WORA) to the server.

** It provides simplified connectivity. J2EE technology makes it easier to connect the applications and systems you already have and bring those capabilities to the web, to cell phones, and to devices. J2EE offers Java Message Service for integrating diverse applications in a loosely coupled, asynchronous way. The J2EE platform also offers CORBA support for tightly linking systems through remote method calls. In addition, the J2EE platform has J2EE Connectors for linking to enterprise information systems such as ERP systems, packaged financial applications, and CRM applications.

** By offering one platform with faster solution delivery time to market, freedom of choice, and simplified connectivity, the J2EE platform helps IT by reducing TCO and simultaneously avoiding single-source for their enterprise software needs.

Q. Can the J2EE platform interoperate with other WS-I implementations?
Yes, if the other implementations are WS-I compliant.

Q. What technologies are included in the J2EE platform?
The primary technologies in the J2EE platform are: Java API for XML-Based RPC (JAX-RPC), JavaServer Pages, Java Servlets, Enterprise Java Beans components, J2EE Connector Architecture, J2EE Management Model, J2EE Deployment API, Java Management Extensions (JMX), J2EE Authorization Contract for Containers, Java API for XML Registries (JAXR), Java Message Service (JMS), Java Naming and Directory Interface (JNDI), Java Transaction API (JTA), CORBA, and JDBC data access API.

Q. What’s new in the J2EE 1.4 platform?
** The Java 2 Platform, Enterprise Edition version 1.4 features complete Web services support through the new JAX-RPC 1.1 API, which supports service endpoints based on servlets and enterprise beans. JAX-RPC 1.1 provides interoperability with Web services based on the WSDL and SOAP protocols. The J2EE 1.4 platform also supports the Web Services for J2EE specification (JSR 921), which defines deployment requirements for Web services and utilizes the JAX-RPC programming model. In addition to numerous Web services APIs, J2EE 1.4 platform also features support for the WS-I Basic Profile 1.0. This means that in addition to platform independence and complete Web services support, J2EE 1.4 offers platform Web services interoperability.

** The J2EE 1.4 platform also introduces the J2EE Management 1.0 API, which defines the information model for J2EE management, including the standard Management EJB (MEJB). The J2EE Management 1.0 API uses the Java Management Extensions API (JMX). The J2EE 1.4 platform also introduces the J2EE Deployment 1.1 API, which provides a standard API for deployment of J2EE applications.

** The J2EE platform now makes it easier to develop web front ends with enhancements to Java Servlet and JavaServer Pages (JSP) technologies. Servlets now support request listeners and enhanced filters. JSP technology has simplified the page and extension development models with the introduction of a simple expression language, tag files, and a simpler tag extension API, among other features. This makes it easier than ever for developers to build JSP-enabled pages, especially those who are familiar with scripting languages.

** Other enhancements to the J2EE platform include the J2EE Connector Architecture, which provides incoming resource adapter and Java Message Service (JMS) pluggability. New features in Enterprise JavaBeans (EJB) technology include Web service endpoints, a timer service, and enhancements to EJB QL and message-driven beans. The J2EE 1.4 platform also includes enhancements to deployment descriptors. They are now defined using XML Schema which can also be used by developers to validate their XML structures.

Q. What is the J2EE 1.4 SDK?
The Java 2 SDK, Enterprise Edition 1.4 (J2EE 1.4 SDK) is a complete package for developing and deploying J2EE 1.4 applications. The J2EE 1.4 SDK contains the Sun Java System Application Server Platform Edition 8, the J2SE 1.4.2 SDK, J2EE 1.4 platform API documentation, and a slew of samples to help developers learn about the J2EE platform and technologies and prototype J2EE applications. The J2EE 1.4 SDK is for both development and deployment.

Q. Which version of the platform should I use now — 1.4 or 1.3?