1. What is abstract
A Java keyword used in a class definition to specify that a class is not to be instantiated, but rather inherited by other classes. An abstract class can have abstract methods that are not implemented in the abstract class, but in subclasses.
2. What is abstract class
A class that contains one or more abstract methods, and therefore can never be instantiated. Abstract classes are defined so that other classes can extend them and make them concrete by implementing the abstract methods.
3. What is abstract method
A method that has no implementation.
4. What is Abstract Window Toolkit (AWT)
A collection of graphical user interface (GUI) components that were implemented using native-platform versions of the components. These components provide that subset of functionality which is common to all native platforms. Largely supplanted by the Project Swing component set. See also Swing.
5. 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.
6. What is ACID
The acronym for the four properties guaranteed by transactions: atomicity, consistency, isolation, and durability.
7. What is actual parameter list
The arguments specified in a particular method call. See also formal parameter list.
8. What is API
Application Programming Interface. The specification of how a programmer writing an application accesses the behavior and state of classes and objects.
9. What is applet
A component that typically executes in a Web browser, but can execute in a variety of other applications or devices that support the applet programming model.
10. What is ASCII
American Standard Code for Information Interchange. A standard assignment of 7-bit numeric codes to characters. See also Unicode.
11. What is atomic
Refers to an operation that is never interrupted or left in an incomplete state under any circumstance
12. What is authentication
The process by which an entity proves to another entity that it is acting on behalf of a specific identity.
13. What is autoboxing
Automatic conversion between reference and primitive types.
14. What is bean
A reusable software component that conforms to certain design and naming conventions. The conventions enable beans to be easily combined to create an application using tools that understand the conventions.
15. What is binary operator
An operator that has two arguments.
16. What is bitwise operator
An operator that manipulates the bits of one or more of its operands individually and in parallel. Examples include the binary logical operators (&, |, ^), the binary shift operators (>, >>> ) and the unary one's complement operator (~).
17. What is block
In the Java programming language, any code between matching braces. Example: { x = 1; }.
18. 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.
19. 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.
20. What is bytecode
Machine-independent code generated by the Java compiler and executed by the Java interpreter.
1. 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.
2. What is casting
Explicit conversion from one data type to another.
3. 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.
4. What is "abstract schema"
The part of an entity bean's deployment descriptor that defines the bean's persistent fields and relationships.
5. What is "abstract schema name"
A logical name that is referenced in EJB QL queries.
6. 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.
7. What is "ACID"
The acronym for the four properties guaranteed by transactions: atomicity, consistency, isolation, and durability.
8. What is "activation"
The process of transferring an enterprise bean from secondary storage to memory. (See passivation.)
9. What is "anonymous access"
Accessing a resource without authentication.
10. 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.
11. 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.
12. 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.
13. 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.
14. 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.
15. What is codebase
Works together with the code attribute in the <applet> 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.</applet>
16. 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 /*...*/.
17. What is commit
The point in a transaction when all updates to any resources involved in the transaction are made permanent.
18. 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.
19. 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.
20. What is compositing
The process of superimposing one image on another to create a single image.
21. 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.
22. 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.
23. What is const
A reserved Java keyword not used by current versions of the Java programming language.
24. 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.
25. 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.
26. What is CORBA
Common Object Request Broker Architecture. A language independent, distributed object model specified by the Object Management Group (OMG).
27. 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. .
28. What is core packages
The required set of APIs in a Java platform edition which must be supported in any and all compatible implementations.
29. What is credentials
The information describing the security attributes of a principal. Credentials can be acquired only through authentication or delegation.
30. 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.
31. 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.
32. What is default
A Java keyword optionally used after all case conditions in a switch statement. If all case conditions are not matched by the value of the switch variable, the default keyword will be executed.
33. What is definition
A declaration that reserves storage (for data) or provides implementation (for methods). See also declaration.
34. What is delegation
An act whereby one principal authorizes another principal to use its identity or privileges with some restrictions.
35. What is deprecation
Refers to a class, interface, constructor, method or field that is no longer recommended, and may cease to exist in a future version.
36. What is derived from
Class X is "derived from" class Y if class X extends class Y. See also subclass, superclass.
37. What is distributed
Running in more than one address space.
38. What is distributed application
An application made up of distinct components running in separate runtime environments, usually on different platforms connected through a network. Typical distributed applications are two-tier (client/server), three-tier (client/middleware/server), and n-tier (client/multiple middleware/multiple servers).
39. What is do
A Java keyword used to declare a loop that will iterate a block of statements. The loop's exit condition can be specified with the while keyword.
40. What is DOM
Document Object Model. A tree of objects with interfaces for traversing the tree and writing an XML version of it, as defined by the W3C specification.
41. What is double
A Java keyword used to define a variable of type double.
42. What is double precision
In the Java programming language specification, describes a floating point number that holds 64 bits of data. See also single precision.
43. What is DTD
Document Type Definition. A description of the structure and properties of a class of XML files.
44. What is else
A Java keyword used to execute a block of statements in the case that the test condition with the if keyword evaluates to false.
45. What is EmbeddedJava Technology
The availability of Java 2 Platform, Micro Edition technology under a restrictive license agreement that allows a licensee to leverage certain Java technologies to create and deploy a closed-box application that exposes no APIs.
46. What is encapsulation
The localization of knowledge within a module. Because objects encapsulate data and implementation, the user of an object can view the object as a black box that provides services. Instance variables and methods can be added, deleted, or changed, but as long as the services provided by the object remain the same, code that uses the object can continue to use it without being rewritten. See also instance variable, instance method.
47. What is enum
A Java keyword used to declare an enumerated type.
48. What is enumerated type
A type whose legal values consist of a fixed set of constants.
49. What is exception
An event during program execution that prevents the program from continuing normally; generally, an error. The Java programming language supports exceptions with the try, catch, and throw keywords. See also exception handler.
50. What is exception handler
A block of code that reacts to a specific type of exception. If the exception is for an error that the program can recover from, the program can resume executing after the exception handler has executed.
51. What is executable content
An application that runs from within an HTML file. See also applet.
52. What is extends
Class X extends class Y to add functionality, either by adding fields or methods to class Y, or by overriding methods of class Y. An interface extends another interface by adding methods. Class X is said to be a subclass of class Y. See also derived from.
53. What is field
A data member of a class. Unless specified otherwise, a field is not static.
54. What is final
A Java keyword. You define an entity once and cannot change it or derive from it later. More specifically: a final class cannot be subclassed, a final method cannot be overridden and a final variable cannot change from its initialized value.
55. What is finally
A Java keyword that executes a block of statements regardless of whether a Java Exception, or run time error, occurred in a block defined previously by the try keyword.
56. What is float
A Java keyword used to define a floating point number variable.
57. What is for
A Java keyword used to declare a loop that reiterates statements. The programmer can specify the statements to be executed, exit conditions, and initialization variables for the loop.
58. What is FTP
File Transfer Protocol. FTP, which is based on TCP/IP, enables the fetching and storing of files between hosts on the Internet. See also TCP/IP.
59. What is formal parameter list
The parameters specified in the definition of a particular method. See also actual parameter list.
60. What is garbage collection
The automatic detection and freeing of memory that is no longer in use. The Java runtime system performs garbage collection so that programmers never explicitly free objects.
61. What is generic
A class, interface, or method that declares one or more type variables. These type variables are known as type parameters. A generic declaration defines a set of parameterized types, one for each possible invocation of the type parameter section. At runtime, all of these parameterized types share the same class, interface, or method.
62. What is goto
This is a reserved Java keyword. However, it is not used by current versions of the Java programming language.
63. What is group
A collection of principals within a given security policy domain.
64. What is GUI
Graphical User Interface. Refers to the techniques involved in using graphics, along with a keyboard and a mouse, to provide an easy-to-use interface to some program.
65. What is hexadecimal
The numbering system that uses 16 as its base. The marks 0-9 and a-f (or equivalently A-F) represent the digits 0 through 15. In programs written in the Java programming language, hexadecimal numbers must be preceded with 0x. See also octal.
66. What is hierarchy
A classification of relationships in which each item except the top one (known as the root) is a specialized form of the item above it. Each item can have one or more items below it in the hierarchy. In the Java class hierarchy, the root is the Object class.
67. What is HTML
HyperText Markup Language. This is a file format, based on SGML, for hypertext documents on the Internet. It is very simple and allows for the embedding of images, sounds, video streams, form fields and simple text formatting. References to other objects are embedded using URLs.
68. What is HTTP
HyperText Transfer Protocol. The Internet protocol, based on TCP/IP, used to fetch hypertext objects from remote hosts. See also TCP/IP.
69. What is HTTPS
HyperText Transfer Protocol layered over the SSL protocol.
70. What is IDL
Interface Definition Language. APIs written in the Java programming language that provide standards-based interoperability and connectivity with CORBA (Common Object Request Broker Architecture).
71. What is identifier
The name of an item in a program written in the Java programming language.
72. What is IIOP
Internet Inter-ORB Protocol. A protocol used for communication between CORBA object request brokers.
73. What is if
A Java keyword used to conduct a conditional test and execute a block of statements if the test evaluates to true.
74. What is impersonation
An act whereby one entity assumes the identity and privileges of another entity without restrictions and without any indication visible to the recipients of the impersonator's calls that delegation has taken place. Impersonation is a case of simple delegation.
75. What is implements
A Java keyword included in the class declaration to specify any interfaces that are implemented by the current class.
76. What is import
A Java keyword used at the beginning of a source file that can specify classes or entire packages to be referred to later without including their package names in the reference.
77. What is inheritance
The concept of classes automatically containing the variables and methods defined in their supertypes. See also superclass, subclass.
78. What is instance
An object of a particular class. In programs written in the Java programming language, an instance of a class is created using the new operator followed by the class name.
79. What is instance method
Any method that is invoked with respect to an instance of a class. Also called simply a method. See also class method.
80. What is instance variable
Any item of data that is associated with a particular object. Each instance of a class has its own copy of the instance variables defined in the class. Also called a field. See also class variable.
81. What is instanceof
A two-argument Java keyword that tests whether the runtime type of its first argument is assignment compatible with its second argument.
82. What is int
A Java keyword used to define a variable of type integer.
83. What is interface
A Java keyword used to define a collection of method definitions and constant values. It can later be implemented by classes that define this interface with the "implements" keyword.
84. What is Internet
An enormous network consisting of literally millions of hosts from many organizations and countries around the world. It is physically put together from many smaller networks and data travels by a common set of protocols.
85. What is IP
Internet Protocol. The basic protocol of the Internet. It enables the unreliable delivery of individual packets from one host to another. It makes no guarantees about whether or not the packet will be delivered, how long it will take, or if multiple packets will arrive in the order they were sent. Protocols built on top of this add the notions of connection and reliability. See also TCP/IP.
86. What is interpreter
A module that alternately decodes and executes every statement in some body of code. The Java interpreter decodes and executes bytecode for the Java virtual machine1. See also compiler, runtime system.
87. What is JAIN
See: Java APIs for Integrated Networks (JAIN)
88. What is JAR
JAR (Java Archive) is a platform-independent file format that aggregates many files into one. Multiple applets written in the Java programming language, and their requisite components (.class files, images, sounds and other resource files) can be bundled in a JAR file and subsequently downloaded to a browser in a single HTTP transaction. It also supports file compression and digital signatures.
89. What is Java
A set of technologies for creating and safely running software programs in both stand-alone and networked environments.
90. What is Java 2 Platform ? Enterprise Edition (J2EE platform), Micro Edition (J2ME platform) , Standard Edition (J2SE platform)
The second generation of the Java platform. (The first generation was the JDK.) Also see "Java Platform" and "Java Platform Editions".
91. What is Java 2 SDK, Standard Edition
The Software Development Kit (SDK) is development environment for building applications, applets, and components using the Java programming language. This SDK provides a reference implementation of the J2SE platform.
92. What is Java APIs for Integrated Networks (JAIN)
enables the rapid development of Next Generation telecom products and services on the Java platform.
93. What is Java Card API
An ISO 7816-4 compliant application environment focused on smart cards.
94. What is Java Compatibility Kit (JCK)
A test suite, a set of tools, and other requirements used to certify a Java platform implementation conformant both to the applicable Java platform specifications and to Java Software reference implementations.
95. What is Java Database Connectivity (JDBC)
An industry standard for database-independent connectivity between the Java platform and a wide range of databases. The JDBC provides a call-level API for SQL-based database access.
96. What is Java Development Kit (JDK)
A software development environment for writing applets and applications in the Java programming language. Technically, the JDK is the correct name for all versions of the Java platform from 1.0 to 1.1.x.
97. What is Java Foundation Classes (JFC)
An extension that adds graphical user interface class libraries to the Abstract Windowing Toolkit (AWT).
98. What is Java IDL
Java Interface Definition Language
99. What is Java Interface Definition Language (IDL)
A set of Java APIs that provide CORBA (Common Object Request Broker Architecture) interoperability and connectivity capabilities for the J2EE platform. These capabilities enable J2EE applications to invoke operations on remote network services using the OMG IDL and IIOP.
100. What is Java Media APIs
A set of APIs that support the integration of audio and video clips, 2D fonts, graphics, and images as well as 3D models and telephony.
101. What is Java Media Framework
The core framework supports clocks for synchronizing between different media (e.g., audio and video output). The standard extension framework allows users to do full audio and video streaming.
102. What is Java Naming and Directory Interface (JNDI)
A set of APIs that assists with the interfacing to multiple naming and directory services.
103. What is Java Native Interface
A standard programming interface for writing Java native methods and embedding the JVM into native applications. The primary goal is binary compatibility of native method libraries across all JVM implementations on a given platform.
104. What is Java Platform
Consists of class libraries, a Java virtual machine (JVM) and class loader (which comprise the runtime environment) and a compiler, debugger and other tools (which comprise the development kit). In addition, the runtime platform is subject to a set of compatibility requirements to ensure consistent and compatible implementations. Implementations that meet the compatibility requirements may qualify for Sun's targeted compatibility brands. Java 2 is the current generation of the Java Platform.
105. What is Java Platform Editions
A Java platform "edition" is a definitive and agreed-upon version of the Java platform that provides the functionality needed over a broad market segment. An edition is comprised of two kinds of API sets: (i) "core packages," which are essential to all implementations of a given platform edition, and (ii) "optional packages," which are available for a given platform edition and which may be supported in a compatible implementation.
106. There are 3 distinct editions of the Java Platform:
* Java 2 Platform, Enterprise Edition:
The edition of the Java platform that is targeted at enterprises to enable development, deployment, and management of multi-tier server-centric applications.
* Java 2 Platform, Micro Edition:
The edition of the Java platform that is targeted at small, standalone or connectable consumer and embedded devices to enable development, deployment, and management of applications that can scale from smart cards through mobile devices and set-top boxes to conventional computing devices.
* Java 2 Platform, Standard Edition:
The edition of the Java platform that enables development, deployment, and management of cross-platform, general-purpose applications.
107. What is Java Remote Method Invocation (RMI)
A distributed object model for Java program to Java program, in which the methods of remote objects written in the Java programming language can be invoked from other Java virtual machines1, possibly on different hosts.
108. What is Java Runtime Environment (JRE)
A subset of the Java Development Kit (JDK) for end-users and developers who want to redistribute the runtime environment alone. The Java runtime environment consists of the Java virtual machine1, the Java core classes, and supporting files.
109. What is Java virtual machine1
A software "execution engine" that safely and compatibly executes the byte codes in Java class files on a microprocessor (whether in a computer or in another electronic device).
110. What is JavaBeans
A portable, platform-independent reusable component model. A component that conforms to this model is called a bean.
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