Java- j2ee interview questions

1.What is J2EE?
J2EE is an environment for developing and deploying enterprise applications. The J2EE platform consists of a set of services, application programming interfaces (APIs), and protocols that provide the functionality for developing multitiered, web-based applications.

2. What is the J2EE module?
A J2EE module consists of one or more J2EE components for the same container type and one component deployment descriptor of that type.

3. What are the components of J2EE application?
A J2EE component is a self-contained functional software unit that is assembled into a J2EE application with its related classes and files and
communicates with other components. The J2EE specification defines the following J2EE components:

Application clients and applets are client components.
Java Servlet and JavaServer PagesTM (JSPTM) technology
components are web components.

Enterprise JavaBeansTM (EJBTM) components (enterprise
beans) are business components.

Resource adapter components provided by EIS and tool

4. What are the four types of J2EE modules?

1. Application client module
2. Web module
3. Enterprise JavaBeans module
4. Resource adapter module

5. What does application client module contain?
The application client module contains:
–class files,
–an application client deployment descriptoor.
Application client modules are packaged as JAR files
with a .jar extension.

11. What is “application assembler”
A person who combines J2EE components and modules into
deployable application units.

12. What is “application client”
A first-tier J2EE client component that executes in its own Java virtual machine. Application clients have access to some J2EE platform APIs.

13. What is “application client container”
A container that supports application client components.

14. What is “application client module”
A software unit that consists of one or more classes and an application client deployment descriptor.

15. What is “application component provider”
A vendor that provides the Java classes that implement components’ methods, JSP page definitions, and any required deployment descriptors.

16. What is “application configuration resource file”
An XML file used to configure resources for a JavaServer Faces application, to define navigation rules for the application, and to register converters, validators, listeners, renderers, and components with
the application.

17. What is “archiving”
The process of saving the state of an object and restoring it.

18. What is “asant”
A Java-based build tool that can be extended using Java classes. The configuration files are XML-based, calling out a target tree where various tasks get executed.

19. What is “attribute”What is “asant”
A qualifier on an XML tag that provides additional information.

20. What is authentication ?
The process that verifies the identity of a user,device, or other entity in a computer system, usually as a prerequisite to allowing access to resources in a system. The Java servlet specification requires three
types of authentication-basic, form-based, and mutual-and supports digest authentication.


What is authorization?
The process by which access to a method or resource is determined. Authorization depends on the determination of whether the principal associated with a request through authentication is in a given security role. A security role is a logical grouping of users defined
by the person who assembles the application. A deployer maps security roles to security identities.Security identities may be principals or groups in the operational environment.

22. What is authorization constraint
An authorization rule that determines who is permitted to access a Web resource collection.

23. What is B2B
B2B stands for Business-to-business.

24. What is backing bean
A JavaBeans component that corresponds to a JSP page that includes JavaServer Faces components. The backing bean defines properties for the components on the page and methods that perform processing for the component. This processing includes event handling, validation,
and processing associated with navigation.

25. What is basic authentication
An authentication mechanism in which a Web server authenticates an entity via a user name and password obtained using the Web application’s built-in authentication mechanism.

31. What is business logic
The code that implements the functionality of an application. In the Enterprise JavaBeans architecture, this logic is implemented by the methods of an enterprise bean.

32.What is business method
A method of an enterprise bean that implements the business logic or rules of an application.

33. What is callback methods
Component methods called by the container to notify the component of important events in its life cycle.

34. What is caller
Same as caller principal.

35. What is caller principal
The principal that identifies the invoker of the enterprise bean method.

36. What is cascade delete
A deletion that triggers another deletion. A cascade delete can be specified for an entity bean that has container-managed persistence.

37. What is CDATA
A predefined XML tag for character data that means “don’t interpret these characters,” as opposed to parsed character data (PCDATA), in which the normal rules of XML syntax apply. CDATA sections are
typically used to show examples of XML syntax.

38. What is certificate authority
A trusted organization that issues public key certificates and provides identification to the bearer.

39. What is client-certificate authentication
An authentication mechanism that uses HTTP over SSL, in which the server and, optionally, the client authenticate each other with a public key certificate that conforms to a standard that is defined by X.509
Public Key Infrastructure.

40. What is comment
In an XML document, text that is ignored unless the parser is specifically told to recognize it.

41. What is commit
The point in a transaction when all updates to any resources involved in the transaction are made permanent.

42. What is component contract
The contract between a J2EE component and its container. The contract includes life-cycle management of the component, a context interface that the instance uses to obtain various information and services from its container, and a list of services that every container must provide for its components.

43. What is component-managed sign-on
A mechanism whereby security information needed for signing on to a resource is provided by an application component.

44. What is connector
A standard extension mechanism for containers that provides connectivity to enterprise information systems. A connector is specific to an enterprise information system and consists of a resource adapter
and application development tools for enterprise information system connectivity. The resource adapter is plugged in to a container through its support for system-level contracts defined in the Connector

45. What is Connector architecture
An architecture for integration of J2EE products with enterprise information systems. There are two parts to this architecture: a resource adapter provided by an enterprise information system vendor and the J2EE product that allows this resource adapter to plug in.
This architecture defines a set of contracts that a resource adapter must support to plug in to a J2EE product-for example, transactions, security, and resource management.

51. What is context attribute
An object bound into the context associated with a servlet.

52. What is context root
A name that gets mapped to the document root of a Web application.

53. What is conversational state
The field values of a session bean plus the transitive closure of the objects reachable from the bean’s fields. The transitive closure of a bean is defined in terms of the serialization protocol for the Java
programming language, that is, the fields that would be stored by serializing the bean instance.
54. What is CORBA
Common Object Request Broker Architecture. A language-independent distributed object model specified by the OMG.

55. What is create method
A method defined in the home interface and invoked by a client to create an enterprise bean.

56. What is credentials
The information describing the security attributes of a principal.

57. What is CSS
Cascading style sheet. A stylesheet used with HTML and XML documents to add a style to all elements marked with a particular tag, for the direction of browsers or other presentation mechanisms.

58. What is CTS
Compatibility test suite. A suite of compatibility tests for verifying that a J2EE product complies with the J2EE platform specification.

59. What is data
The contents of an element in an XML stream, generally used when the element does not contain any sub elements. When it does, the term content is generally used. When the only text in an XML structure
is contained in simple elements and when elements that have sub elements have little or no data mixed in, then that structure is often thought of as XML data, as opposed to an XML document.

60. What is DDP
Document-driven programming. The use of XML to define applications.

If you have questions, please ask below


  1. Vipin yadav says:

    I am a electronics student

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