Frequently Asked Questions - Java

# Can a main() method of class be invoked in another class?


# What is the difference between java command line arguments and C command line arguments?


# What is the difference between == & .equals


# What is the difference between abstract class & Interface.


# What is singleton class & it's implementation.


# Use of static,final variable


# Examples of final class


# Difference between Event propagation & Event delegation


# Difference between Unicast & Multicast model


# What is a java bean


# What is synchronized keyword used for.


# What are the restrictions of an applet & how to make the applet access the local machines resources.


# What is reflect package used for & the methods of it.


# What is serialization used for


# Can methods be overloaded based on the return types ?


# Why do we need a finalze() method when Garbage Collection is there ?


# Difference between AWT and Swing compenents ?


# Is there any heavy weight component in Swings ?


# Can the Swing application if you upload in net, be compatible with your browser?


# What should you do get your browser compatible with swing components?


# What are the methods in Applet ?


# When is init(),start() called ?


# When you navigate from one applet to another what are the methods called?


# What is the difference between Trusted and Untrusted Applet ?


# What is Exception ?


# What are the ways you can handle exception ?


# When is try,catch block used ?


# What is finally method in Exceptions ?


# What are the types of access modifiers ?


# What is protected and friendly ?


# What are the other modifiers ?


# Is synchronised modifier ?


# What is meant by polymorphism ?


# What is inheritance ?


# What is method Overloading ? What is this in OOPS ?


# What is method Overriding ? What is it in OOPS ?


# Does java support multi dimensional arrays ?


# Is multiple inheritance used in Java ?


# How do you send a message to the browser in JavaScript ?


# Does javascript support multidimensional arrays ?


# Is there any tool in java that can create reports ?


# What is meant by Java ?


# What is meant by a class ?


# What is meant by a method ?


# What are the OOPS concepts in Java ?


# What is meant by encapsulation ? Explain with an example


# What is meant by inheritance ? Explain with an example


# What is meant by polymorphism ? Explain with an example


# Is multiple inheritance allowed in Java ? Why ?


# What is meant by Java interpreter ?


# What is meant by JVM ?


# What is a compilation unit ?


# What is meant by identifiers ?


# What are the different types of modifiers ?


# What are the access modifiers in Java ?


# What are the primitive data types in Java ?


# What is meant by a wrapper class ?


# What is meant by static variable and static method ?


# What is meant by Garbage collection ?


# What is meant by abstract class


# What is meant by final class, methods and variables ?


# What is meant by interface ?


# What is meant by a resource leak ?


# What is the difference between interface and abstract class ?


# What is the difference between public private, protected and static


# What is meant by method overloading ?


# What is meant by method overriding ?


# What is singleton class ?


# What is the difference between an array and a vector ?


# What is meant by constructor ?


# What is meant by casting ?


# What is the difference between final, finally and finalize ?


# What is meant by packages ?


# What are all the packages ?


# Name 2 calsses you have used ?


# Name 2 classes that can store arbitrary number of objects ?


# What is the difference between java.applet.* and java.applet.Applet ?


# What is a default package ?


# What is meant by a super class and how can you call a super class ?


# What is anonymous class ?


# Name interfaces without a method ?


# What is the use of an interface ?


# What is a serializable interface ?


# How to prevent field from serialization ?


# What is meant by exception ?


# How can you avoid the runtime exception ?


# What is the difference between throw and throws ?


# What is the use of finally ?


# Can multiple catch statements be used in exceptions ?


# Is it possible to write a try within a try statement ?


# What is the method to find if the object exited or not ?


# What is meant by a Thread ?


# What is meant by multi-threading ?


# What is the 2 way of creating a thread ? Which is the best way and why?


# What is the method to find if a thread is active or not ?


# What are the thread-to-thread communcation ?


# What is the difference between sleep and suspend ?


# Can thread become a member of another thread ?


# What is meant by deadlock ?


# How can you avoid a deadlock ?


# What are the three typs of priority ?


# What is the use of synchronizations ?


# Garbage collector thread belongs to which priority ?


# What is meant by time-slicing ?


# What is the use of 'this' ?


# How can you find the length and capacity of a string buffer ?


# How to compare two strings ?


# What are the interfaces defined by Java.lang ?


# What is the purpose of run-time class and system class


# What is meant by Stream and Types ?


# What is the method used to clear the buffer ?


# What is meant by Stream Tokenizer ?


# What is serialization and de-serialisation ?


# What is meant by Applet ?


# How to find the host from which the Applet has originated ?


# What is the life cycle of an Applet ?


# How do you load an HTML page from an Applet ?


# What is meant by Applet Stub Interface ?


# What is meant by getCodeBase and getDocumentBase method ?


# How can you call an applet from a HTML file


# What is meant by Applet Flickering ?


# What is the use of parameter tag ?


# What is audio clip Interface and what are all the methods in it ?


# What is the difference between getAppletInfo and getParameterInfo ?


# How to communicate between applet and an applet ?


# What is meant by event handling ?


# What are all the listeners in java and explain ?


# What is meant by an adapter class ?


# What are the types of mouse event listeners ?


# What are the types of methods in mouse listeners ?


# What is the difference between panel and frame ?


# What is the default layout of the panel and frame ?


# What is meant by controls and types ?


# What is the difference between a scroll bar and a scroll panel.


# What is the difference between list and choice ?


# How to place a component on Windows ?


# What are the different types of Layouts ?


# What is meant by CardLayout ?


# What is the difference between GridLayout and GridBagLayout


# What is the difference between menuitem and checkboxmenu item.


# What is meant by vector class, dictionary class , hash table class,and property class ?


# Which class has no duplicate elements ?


# What is resource bundle ?


# What is an enumeration class ?


# What is meant by Swing ?


# What is the difference between AWT and Swing ?


# What is the difference between an applet and a Japplet


# What are all the components used in Swing ?


# What is meant by tab pans ?


# What is the use of JTree ?


# How can you add and remove nodes in Jtree.


# What is the method to expand and collapse nodes in a Jtree


# What is the use of JTable ?


# What is meant by JFC ?


# What is the class in Swing to change the appearance of the Frame in Runtime.


# How to reduce flicking in animation ?


# What is meant by Javabeans ?


# What is JAR file ?


# What is meant by manifest files ?


# What is Introspection ?


# What are the steps involved to create a bean ?


# Say any two properties in Beans ?


# What is persistence ?


# What is the use of beaninfo ?


# What are the interfaces you used in Beans ?


# What are the classes you used in Beans ?


# What is the diffrence between an Abstract class and Interface


# What is user defined exception ?


# What do you know about the garbate collector ?


# What is the difference between C++ & Java ?


# How do you communicate in between Applets & Servlets ?


# What is the use of Servlets ?


# In an HTML form I have a Button which makes us to open another page in 15 seconds. How will do you that ?


# What is the difference between Process and Threads ?


# How will you initialize an Applet ?


# What is the order of method invocation in an Applet ?


# When is update method called ?


# How will you communicate between two Applets ?


# Have you ever used HashTable and Dictionary ?


# What are statements in JAVA ?


# What is JAR file ?


# What is JNI ?


# What is the base class for all swing components ?


# What is JFC ?


# What is Difference between AWT and Swing ?


# Considering notepad/IE or any other thing as process, What will Happen if you start notepad or IE 3 times? Where 3 processes are started or 3 threads are started ?


# How does thread synchronization occurs inside a monitor ?


# How will you call an Applet using a Java Script function ?


# Is there any tag in HTML to upload and download files ?


# Why do you Canvas ?


# How can you push data from an Applet to Servlet ?


# What are the benefits of Swing over AWT ?


# Where the CardLayout is used ?


# What is the Layout for ToolBar ?


# What is the difference between Grid and GridbagLayout ?


# How will you add panel to a Frame ?


# What is the corresponding Layout for Card in Swing ?


# What is light weight component ?


# What is bean ? Where it can be used ?


# What is difference in between Java Class and Bean ?


# What is the mapping mechanism used by Java to identify IDL language ?


# Diff between Application and Applet ?


# What is serializable Interface ?


# What is the difference between CGI and Servlet ?


# What is the use of Interface ?


# Why Java is not fully objective oriented ?


# Why does not support multiple Inheritance ?


# What it the root class for all Java classes ?


# What is polymorphism ?


# Suppose If we have variable ' I ' in run method, If I can create one or More thread each thread will occupy a separate copy or same variable will be shared ?


# What is Constructor and Virtual function? Can we call Virtual


# Funciton in a constructor ?


# Why we use OOPS concepts? What is its advantage ?


# What is the difference in between C++ and Java ? can u explain in detail?


# What is the exact difference in between Unicast and Multicast object ? Where we will use ?


# How do you sing an Applet ?


# In a Container there are 5 components. I want to display the all the components names, how will you do that one ?


# Why there are some null interface in java ? What does it mean ?


# Give me some null interfaces in JAVA ?


# Tell me the latest versions in JAVA related areas ?


# What is meant by class loader ? How many types are there? When will we use them ?


# What is meant by flickering ?


# What is meant by cookies ? Explain ?


# Problem faced in your earlier project


# How OOPS concept is achieved in Java


# Features for using Java


# How does Java 2.0 differ from Java 1.0


# Public static void main - Explain


# What are command line arguments


# Explain about the three-tier model


# Difference between String & StringBuffer


# Wrapper class. Is String a Wrapper Class


# What are the restriction for static method Purpose of the file class


# Default modifier in Interface


# Difference between Interface & Abstract class


# Can abstract be declared as Final


# Can we declare variables inside a method as Final Variables


# What is the package concept and use of package


# How can a dead thread be started


# Difference between Applet & Application


# Life cycle of the Applet


# Can Applet have constructors


# Differeence between canvas class & graphics class


# Explain about Superclass & subclass


# What is AppletStub


# Explain Stream Tokenizer


# What is the difference between two types of threads


# Checked & Unchecked exception


# Use of throws exception


# What is finally in exception handling Vector class


# What will happen to the Exception object after exception handling


# Two types of multi-tasking


# Two ways to create the thread


# Synchronization


# I/O Filter


# Can applet in different page communicate with each other


# Why Java is not 100 % pure OOPS ? ( EcomServer )


# When we will use an Interface and Abstract class ?


# How to communicate 2 threads each other ?