java most frequently asked questions

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 ?