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Why there are some null interface in java. What does it mean. Give me some null interfaces in JAVA
jimmy514in
- May 18th, 2010
Null Interfaces are markable interfaces. Ex: Cloneable Runnable Serializable Externalizable. SingleThreadModel, Event listener
reddybajjuri
- Mar 27th, 2007
Null Interfaces also know as Marker Interfaces are simply marking the class that implements them.Now when the JVM looks at such a class it allows it to call certain methods.e.g There is a method clone...
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Diff between ArrayList and Vector
sujatham
- Jul 29th, 2007
The Vector and ArrayList classes are implemented using dynamically resizable arrays, providing fast random access and fast list traversal—very much like using an ordinary array. Unlike the Array...
haijing
- Jun 9th, 2007
If you use a Vector in your code and compile it, the compiler will not complain Vector is deprecated. So, I do not think Vector is deprecated. ArrayList is the newer version of Vector, which is not synchronized. ArrayList is recomended for situations where you do not need synchronization.
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What is the Locale class
The Locale class is used to tailor program output to the conventions of a particulargeographic, political, orcultural region.
pon suresh
- Oct 6th, 2012
What is object class in java?
prabakaran29
- Aug 19th, 2012
The locale class to used to tailor program output to the conventions of a particular geographic, political, or cultural region
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What is the use of having finally?
chaithanya chatla
- Dec 28th, 2012
Finally block having the statements which are releasing the resource, closing the streams, closing the connection and so on. If exception is raised or not but closing the resource are necessary. So we can keep statements inside the finally block those should be get executed compulsory.
Ajit4U
- Dec 24th, 2012
Finally is the block which will be executed irrespective of exception caught in catch block.
Hence it is useful to do any resource releasing/ connection closing after exception handling -
Explain about RMI and it's usage
pramod.reddy
- Mar 16th, 2007
For RMI you can find in Appendix of Matering EJB , here is the link http://www.theserverside.com/tt/books/wiley/masteringEJB/downloads/MasteringEJB3rdEd.pdfand comming to servlets basics you can find ...
savitha_shankar
- Mar 15th, 2007
Thanks for ur reply Mr.Pramod Reddy can u suggest a few refernce books which will be simlpe in language about the RMI and Servletsthankyouregards savitha
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How to check the status of a caps lock key..?
You can do it without using key event, by creating an artificial key event using java.awt.Robot class to generate a "simple caracter" key press (for instance KeyEvent.VK_A). Sample Source Code -- May not be accurate but the concept is as follows. import java.awt.*;import java.awt.event.*;public class Test { public static void main(String[] args) throws AWTException...
hobocat
- Dec 20th, 2017
There is same bug: when I changed the capslock's statusthe check result change nothing. "java public static void main(String[] args) throws InterruptedException { whil...
Tim Rousselet
- May 23rd, 2011
You probably need to add !ev.isShiftDown() here if(Character.isUpperCase( ev.getKeyChar())) to check if CapsLock is really on.
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What is meant by abstract class
santosh
- Dec 9th, 2006
Abstract class nnothing but a class which can declear a data but in abclass the data canot shown it internaly working.
smitac
- Oct 9th, 2006
Sometimes in the desin it would require that,object of a base class should not be created.But only use thee base class pointer for upcasting purpose.This is accomplished by making that class abstract,...
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What is the difference between panel and frame
Mranal Jadhav
- Jan 17th, 2016
Frame: The frame encapsulate the commonly use windows and it is a subclass of a window that has title bar, menu bar, status bar, borders and windows resizing corners. Panel: The panel is the subclas...
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Can we have 3 methods in a single servlet i.e service(), doPost() and doGet() method. If yes, then what method will be called. Tell me the servlet cycle in such cases
sireesh
- Mar 25th, 2006
If we want to handle all the request types from a single method then the servlet can simply implement the service() method.However if we choose to implement the sevice() method we cannot use the doGet() or doPost methods unless we call super.service at the beginning of the service method.
ravikumarzee@gmail.com
- Feb 20th, 2006
U can have all the 3 methods in a servlet, but only the service() method gets called.Servlet Container always calls the Service(ServletRequest, ServletResponse) method whenever a new request has come....
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Difference between HashMap and TreeMap
Tafazzul hasan
- Feb 21st, 2007
Differences... a> HashMap provides the implementation of Map Interface by using hashtable where as TreeMap provides the implementation o...
justAnother
- Nov 16th, 2005
The following link provides a table with details of collections in java. http://mindprod.com/jgloss/collection.html
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Is marker interface haveing methods
VijayAravind
- Sep 18th, 2009
In Java Programming, Interfaces with no methods is called as Marker Interface. Marker Interfaces are implemented by the classes or their SUper class in order to do some functions. Marker interface are Serializable, clonable, Single Threaded Model, Event listenter.
sudha
- May 23rd, 2006
99% of marker interface have no methods because Runnable is a marker interface which has one method called as public void run()
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Abstract class A{void display(){}}class B extends A{void display(){}psvm(String args[]){how can i instantiate the overridden method in class A}}
r.praveenkumar
- Apr 11th, 2009
All three answers above are correct. in 3rd one we are assigning object of B to reference of B itself. But in first and second answers we are assigning object of B to Reference of A. In all three cases JVM will invoke B's display() only.
anithananduri
- Apr 9th, 2009
abstract class A { void display() { } }class B extends A { void display() { &n...
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What is difference in between Java Class and Bean
sivanesh.a
- Dec 24th, 2006
Java Bean: we have getter and setter methods. but in java class its not available.
Ganesh Krishnan
- Jun 28th, 2006
The most important difference is that a Bean is serializable. Just adding getters & setters to a class wont mark it as a Bean.cheers~gk
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State true or false :- The suspend()method is used to terminate a thread?
A) TrueB) False
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Which of the following types of class members can be part of the internal part of a class? (Select multiple)
A) Public instance variablesB) Private instance variablesC) Public methodsD) Private methods
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Which of the following classes is used to perform basic console I/O?
A) SystemB) SecurityManagerC) MathD) Runtime
Nitin Prajapati
- Apr 14th, 2015
System
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How do you create a Reader object from an InputStream object?
A) Use the static createReader( ) method of InputStream class.B) Use the static createReader( ) method of Reader class.C) Create an InputStreamReader object, passing the InputStream object as an argument to the InputStreamReader constructor.D) Create an OutputStreamReader object, passing the InputStream object as an argument to the OutputStreamReader constructor.
Rahul Kolhe
- Sep 14th, 2011
Create an outputstreamreader object, passing the inputstream object as an argument to the outputstreamreader constructor
Java Interview Questions
Ans