J2EE Interview Questions

JAR - Java ARchive Its a file format based on the ZIP file format and similar to ZIP format this is also used for aggregating many files (many be of different types) into one aggregate file. This agg...

jar files: These files are with the .jar extension. The .jar files contain the libraries, resources and accessories files like property files. .war files: These files are with the .war extension. Th...

A three-tier architecture is any system which enforces a general separation between the following three parts: 1. Client Tier or user interface 2. Middle Tier or business logic 3. Data Storage Tie...

middle tier is primarly based on processing the bussiness logic. The main idea of dividing into tiers is like the application developer can concentrate on specific tier in developing webapplicati...

Java projects are more secured than other languages because after compilation of java program byte code is generated. And byte code is unreadable code. Any person cant read the byte code. then the project become more secure.

J2EE application can be made secure by implementing: 1. Authentication 2. Authorization 3. Encrypt the information by making the transport guarantee as Confidential. Authentication verifies if the us...

Security Purpose

java does not support pointer because of security purpose, as if it have pointer then till easy to find out the addressing of its application which may make it unsecure

java uses the concept of reference variable which is same as pointer....

java.util.date is used to show date and time of the system

java.sql.date is used to show the date of retrieved data from database and also it shows entered date to database

Explanation: public class ((java.util.Date extends java.lang.Object)) implements java.io.Serializ able,java.lang.Cloneable,java.lang.Comparable java.sql.Date extends the java.uti.Date cls obj so jav...

Bit Twiddling was used in earlier days for efficiency. It is a technique used for bit manipulation. Java bitwise and bit shift operators such as NOT, AND, OR, XOR, LEFT-SHIFT, RIGHT-SHIFT, UNSIGNED-RI...

In this two threads cannot use the same resource simultaneously beacuse the thread execution gets interrupted or terminated hence only a single thread can share resource at a time.

It is a process of ensuring that if two or more threads are using  a shared resource then only one thread get access to that shared resource at a time.

Synchronization contains empty implementation, so no method is used.

Java is the extension of C++ language and javax files are those where it stores the entire program for execution in the form of files and termed as javax files

javax is the extension for the java packages

Code
javax.swing extension for java.awt

Java is the basic object oriented programmng language and Java script can be used in style sheets making and in HTML documentation

java-script is also same as like java only.But java is used in server side scripting and the javascript is used in client side scripting. I will say a real time scenario here consider the normal user...

The class cannot be declared as protected..

we can not declare a class as protected or private compiler will gives an error like ; xyz.java:1: modifier protected not allowed here protected class xyz{ ^ 1 error

Code
protected class xyz{
}
 

A variable can be declared but when program execution is running one can change its variable but when it reaches a final result the varable cannot be changed..hence it is declared as final variable

when a variable is declared as final we cant change its value again. we use final variable to declare a constant so when we declare a variable as final and if we were allowed to not to give its value ...

Projects needs to be designed carefully which must be meaningful according to the readers and learners..It must be planned in such a way so that it can be followed easily a project should contain a meaninngful data related to topic prescribed

Let me start with an example.Consider a development projectInitiation : Requirements gatheringPlanning : From the scratch to the end product based of the needs and requirements provided.Design: Once t...

DAO decides to recieve the appropriate application from java and implemeting it a runtime...during execution..

DAO is Data Access Object.

anyone pls send me project architecture diagram. and plz differentiate project architecture and project approach briefly. Does project architecture follows project approach.
Is project architecture is same for all struts, spring etc for all. or different architectures for all. pls tell me

Can anyone send me project architecture diagram. and plz differentiate project architecture and project approach briefly. Does project architecture follows project approach.

yes.But we can not declare the outer class as private..If did so,the compiler will generate the error as the modifier private is not allowed here,but we can declare the inner class as private.

Not true, the class can be accessed by an outer-class.

Java supports single inheritance like C++, but does not supports multiple inheritance because of diamond problem.

In Java multiple inheritance means implementing the multiple interface, at the same time you can inherit only one class and implement multiple interface.

In every class or method, there will be a calling function and a called function.When ever a function(calling function) calls another function(called function), the called function is expected to repl...

Let me tell you where exactly it is used and what it does as per my knowledge.Application library used by OpenOffice.org, an open-source productivity suite; contains the functionality for the componen...

Problems with large Queue :1) Space.2) Inserting and deleting.3) Time to perform operations.4) Additional cost.There are few ways to implement very large queues:1)Using flat-files:A "flat file&qu...