J2EE Interview Questions and Answers7

What is entity bean ?
An enterprise bean that represents persistent data maintained in a database. An entity bean can manage its own persistence or can delegate this function to its container. An entity bean is identified by a primary key. If the container in which an entity bean is hosted crashes, the entity bean, its primary key, and any remote references survive the crash.
What is entity reference ?
A reference to an entity that is substituted for the reference when the XML document is parsed. It can reference a predefined entity such as < or reference one that is defined in the DTD. In the XML data, the reference could be to an entity that is defined in the local subset of the DTD or to an external XML file (an external entity). The DTD can also carve out a segment of DTD specifications and give it a name so that it can be reused (included) at multiple points in the DTD by defining a parameter entity. 

What is error ?
A SAX parsing error is generally a validation error; in other words, it occurs when an XML document is not valid, although it can also occur if the declaration specifies an XML version that the parser cannot handle. See also fatal error, warning.

What is Extensible Markup Language ?
XML.
What is external entity ?
An entity that exists as an external XML file, which is included in the XML document using an entity reference.
What is external subset ?
That part of a DTD that is defined by references to external DTD files.
What is fatal error ?
A fatal error occurs in the SAX parser when a document is not well formed or otherwise cannot be processed. See also error, warning.
What is filter ?
An object that can transform the header or content (or both) of a request or response. Filters differ from Web components in that they usually do not themselves create responses but rather modify or adapt the requests for a resource, and modify or adapt responses from a resource. A filter should not have any dependencies on a Web resource for which it is acting as a filter so that it can be composable with more than one type of Web resource.
What is filter chain ?
A concatenation of XSLT transformations in which the output of one transformation becomes the input of the next.
What is finder method ?
A method defined in the Interview Questions - Home interface and invoked by a client to locate an entity bean.
What is form-based authentication ?
An authentication mechanism in which a Web container provides an application-specific form for logging in. This form of authentication uses Base64 encoding and can expose user names and passwords
What is general entity ?
An entity that is referenced as part of an XML document's content, as distinct from a parameter entity, which is referenced in the DTD. A general entity can be a parsed entity or an unparsed entity.
What is group ?
An authenticated set of users classified by common traits such as job title or customer profile. Groups are also associated with a set of roles, and every user that is a member of a group inherits all the roles assigned to that group.
What is handle ?
An object that identifies an enterprise bean. A client can serialize the handle and then later deserialize it to obtain a reference to the enterprise bean.
What is Interview Questions - Home handle ?
An object that can be used to obtain a reference to the Interview Questions - Home interface. A Interview Questions - Home handle can be serialized and written to stable storage and de-serialized to obtain the reference.
What is Interview Questions - Home interface ?
One of two interfaces for an enterprise bean. The Interview Questions - Home interface defines zero or more methods for managing an enterprise bean. The Interview Questions - Home interface of a session bean defines create and remove methods, whereas the Interview Questions - Home interface of an entity bean defines create, finder, and remove methods.