J2SE Interview Questions and Answers 2

What is Boolean ?
Refers to an expression or variable that can have only a true or false value. The Java programming language provides the boolean type and the literal values true and false.

What is break ?
A Java keyword used to resume program execution at the statement immediately following the current statement. If followed by a label, the program resumes execution at the labeled statement.

What is bytecode ?
Machine-independent code generated by the Java compiler and executed by the Java interpreter.

What is case ?
A Java keyword that defines a group of statements to begin executing if a value specified matches the value defined by a preceding switch keyword.

What is casting ?
Explicit conversion from one data type to another.

What is catch ?
A Java keyword used to declare a block of statements to be executed in the event that a Java exception, or run time error, occurs in a preceding try block.

What is "abstract schema" ?
The part of an entity bean's deployment descriptor that defines the bean's persistent fields and relationships.

What is "abstract schema name" ?
A logical name that is referenced in EJB QL queries.

What is "access control" ?
The methods by which interactions with resources are limited to collections of users or programs for the purpose of enforcing integrity, confidentiality, or availability constraints.

What is "ACID" ?
The acronym for the four properties guaranteed by transactions: atomicity, consistency, isolation, and durability.

What is "activation" ?

The process of transferring an enterprise bean from secondary storage to memory. (See passivation.)

What is "anonymous access" ?
Accessing a resource without authentication.

What is class ?
In the Java programming language, a type that defines the implementation of a particular kind of object. A class definition defines instance and class variables and methods, as well as specifying the interfaces the class implements and the immediate superclass of the class. If the superclass is not explicitly specified, the superclass will implicitly be Object.

What is class method ?
A method that is invoked without reference to a particular object. Class methods affect the class as a whole, not a particular instance of the class. Also called a static method. See also instance method.

What is class variable ?
A data item associated with a particular class as a whole--not with particular instances of the class. Class variables are defined in class definitions. Also called a static field. See also instance variable.

What is classpath ?
An environmental variable which tells the Java virtual machine1 and Java technology-based applications where to find the class libraries, including user-defined class libraries.

What is client ?
In the client/server model of communications, the client is a process that remotely accesses resources of a compute server, such as compute power and large memory capacity.

J2SE Interview Questions and Answers 3

What is CODEBASE ?
Works together with the code attribute in the tag to give a complete specification of where to find the main applet class file: code specifies the name of the file, and codebase specifies the URL of the directory containing the file.

What is comment ?
In a program, explanatory text that is ignored by the compiler. In programs written in the Java programming language, comments are delimited using // or /*...*/.

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

What is compilation unit ?
The smallest unit of source code that can be compiled. In the current implementation of the Java platform, the compilation unit is a file.

What is compiler ?
A program to translate source code into code to be executed by a computer. The Java compiler translates source code written in the Java programming language into bytecode for the Java virtual machine1. See also interpreter.

What is compositing ?
The process of superimposing one image on another to create a single image.

What is constructor ?
A pseudo-method that creates an object. In the Java programming language, constructors are instance methods with the same name as their class. Constructors are invoked using the new keyword.
What is const ?
A reserved Java keyword not used by current versions of the Java programming language.

What is continue ?
A Java keyword used to resume program execution at the end of the current loop. If followed by a label, continue resumes execution where the label occurs.

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.

What is CORBA ?
Common Object Request Broker Architecture. A language independent, distributed object model specified by the Object Management Group (OMG).

What is core class ?
A public class (or interface) that is a standard member of the Java Platform. The intent is that the core classes for the Java platform, at minimum, are available on all operating systems where the Java platform runs. A program written entirely in the Java programming language relies only on core classes, meaning it can run anywhere. .

What is core packages ?
The required set of APIs in a Java platform edition which must be supported in any and all compatible implementations.

What is credentials ?
The information describing the security attributes of a principal. Credentials can be acquired only through authentication or delegation.

What is critical section ?
A segment of code in which a thread uses resources (such as certain instance variables) that can be used by other threads, but that must not be used by them at the same time.

What is declaration ?
A statement that establishes an identifier and associates attributes with it, without necessarily reserving its storage (for data) or providing the implementation (for methods). See also definition.