What is the use of Interface ?

Java achieve inheritance using two notions : By extending the class and implementing the interface. 
When you \"implement\" an interface, you are stipulating that your class adheres to the \"contract\" of the interface that you specified. Use interfaces to say \"What objects can do\" or \"What can be done to an object. 
\"Interfaces are intended to define the what without defining the how. Interfaces provide a form of multiple inheritance. A class can extend only one other class. Interfaces are limited to public methods and constants with no implementation.

Interface

How would you implement a thread pool?

What difference between constructor and method?

Example for transient variable?

What is the difference between frame work and api? Why we called collections framework?

instanceof in Java

What are legacy classes in java?

what is the return type of delete method in StringBuffer ?

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 use of static, final variable?

Examples of final class.

What is a java bean?

What is use of synchronized keyword?

What is reflect package used for & the methods of it?

What is use of serialization?

Can methods be overloaded based on the return types ?

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

Difference between AWT and Swing components ?

Is there any heavy weight component in Swings ?

What are the methods in Applet ?

When is init(), start() called ?

What is Exception ?

What are the ways you can handle exception ?

What is finally method in Exceptions ?

What are the types of access modifiers ?

What are the other modifiers in java ?

Is synchronized modifier ?

What is meant by polymorphism ?

What is inheritance ?

What is method Overloading ?

What is method Overriding ?

Does java support multi dimensional arrays ?

Is multiple inheritance used in Java ?

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 mean by JVM ?

What is meant by identifiers ?

What are the different types of modifiers ?

What are the primitive data types in Java ?

What is mean by a wrapper class ?

What is Garbage collection ?

What is mean by final class, methods and variables ?

What is mean by interface ?

What is the difference between an array and a vector ?

What is singleton class ?

What is constructor ?

What is casting ?

What is the difference between final, finally and finalize ?

What is mean by packages in java?

Name 5 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 anonymous class ?

What is the use of an interface ?

What is a serializable interface ?

How to prevent field from serialization ?

What is the difference between throw and throws ?

Can multiple catch statements be used in exceptions ?

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

What is mean by a Thread ?

What is mean 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 is the difference between sleep and suspend ?

Can thread become a member of another thread ?

What are the three types of priority ?

Garbage collector thread belongs to which priority ?

What is the use of this ?

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

How to compare two strings ?

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

What is the method used to clear the buffer ?

What is mean by Stream Tokenizer ?

What is serialization and de-serialisation ?

What is mean 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 mean by getCodeBase and getDocumentBase method ?

What is the use of parameter tag ?

What is the difference between getAppletInfo and getParameterInfo ?

How to communicate between applet and an applet ?

What is mean by event handling ?

What are all the listeners in java and explain ?

What is mean 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 the difference between list and choice ?

What are the different types of Layouts ?

What is mean by CardLayout ?

What is the difference between GridLayout and GridBagLayout?

Which class has no duplicate elements ?

What is mean by Swing ?

What is the difference between an applet and a Japplet?

What are all the components used in Swing ?

What is mean by tab pans ?

What is the use of JTree ?

What is the use of JTable ?

What is mean by JFC ?

What is JAR file ?

What is mean by manifest files ?

What is two properties in Beans ?

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 difference between C++ & Java ?

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 ?

What is JNI ?

What is the base class for all swing components ?

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

What is the Layout for ToolBar ?

How will you add panel to a Frame ?

What is the corresponding Layout for Card in Swing ?

What is light weight component ?

What is difference in between Java Class and Bean ?

Diff between Application and Applet ?

What is the use of Interface ?

Why Java is not fully objective oriented ?

What it the root class for all Java classes ?

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

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

What is latest versions in JAVA related areas ?

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

public static void main - Explain?

What is difference between String & StringBuffer?

What is Wrapper class. Is String a Wrapper Class?

What is Default modifier in Interface?

Can abstract be declared as Final?

Can we declare variables inside a method as Final Variables?

How can a dead thread be started?

Can Applet have constructors?

What is Checked & Unchecked exception?

Explain. Two types of multi-tasking.

Explain I/O Filter.

Can applet in different page communicate with each other?

What is the difference between == & .equals().

What is the difference between abstract class & Interface.

What is singleton class & how you can implementation it?.

What is use of static, final variable?

Examples of final class.

What is difference between Event propagation & Event delegation?

What is difference between Unicast & Multicast model?

What is a java bean?

What is use of synchronized keyword?

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 use of serialization?

Can methods be overloaded based on the return types ?

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 are the other modifiers ?

Is synchronized modifier ?

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 ?

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 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 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 a resource leak ?

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 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 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 ?

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 communication ?

What are the thread-to-thread communication ?

What is the difference between sleep and suspend ?

Can thread become a member of another thread ?

What is meant by deadlock ?

What is meant by deadlock ?

How can you avoid a deadlock ?

What are the three types of priority ?

What is the use of synchronizations ?

Garbage collector thread belongs to which priority ?

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 ?

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 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 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 ?

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 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 fertilizable Interface ?

What is the difference between CGI and Servlets?

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 ?

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?

What is function in a constructor ?

What is function 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 ?

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

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 ?

Which problem you had faced in your earlier project?

How OOPS concept is achieved in Java?

What is 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?

What is difference between String & StringBuffer?

What is Wrapper class. Is String a Wrapper Class?

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

What is 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?

What is Life cycle of the Applet?

Can Applet have constructors?\

Differeence between canvas class & graphics class?

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?

What is Checked & Unchecked exception?

What is use of throws exception?s

What is finally in exception handling Vector class?

What will happen to the Exception object after exception handling?

Explain. Two types of multi-tasking.

Explain Two ways to create the thread.

Explain Synchronization.

Explain 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 ?

Describe difference between method overriding and overloading?

What is the restriction on an Overridden methods’ accessibility ?

Can a method be overloaded by different return type but same argument type?

Can a method be overloaded by different return type but same argument type?

What is a "stateless" protocol?

What is constructor chaining and how to do this in Java?

What is constructor chaining and how to do this in Java?

What is passed by ref and by value?

What is passed by ref and by value?

How to ensure size of a primitive data type?

Elaborate the Garbage Collection process in Java ?

What is a difference between An interface and an abstract class?

In DB access where to write the query. In JSP or servlet?

In DB access where to write the query. In JSP or servlet?

Explain difference between Constructer and a method

Explain difference between Constructer and a method

What is serialization in Java?

Describe difference between an error and an exception?

What are differences between procedural and object oriented language?

What are differences between procedural and object oriented language?

What is the difference between a Class and an Object ?

Why threads block or enters to waiting state on I/O?

What are transient variables in java?

How Observer and Observable are used?

What is List interface ?

What is the difference between yield() and sleep()?

Can we call finalize() method ?

What is the initial state of a thread when it is created and started?

Can we declare an anonymous class as both extending a class and implementing an interface?

What is the differences between boolean & operator and && operator?

What is an abstract method ?

what is a the difference between System.err and System.out

What is the difference between synchronized block and synchronized method ?

How can you force garbage collection in java?

How can you call a constructor from another constructor ?

How can you call the constructor of super class ?

What must be the order of catch blocks when catching more than one exception?

How can we call a method or variable of the super class from child class ?

If you are overriding equals() method of a class, what other methods you might need to override ?

What is externalizable ?

Does garbage collection guarantee that a program will not run out of memory?

What is a native method?

What is the difference between a continue statement and a break statement?

What must a class do to implement an interface?

What is the difference between notifyand notifyAll method ?

What does wait method do ?

What are the different states of a thread ?

What is the difference between static and non static inner class ?

What is the difference between readers and streams?

Why we cannot override static methods?

When does a compiler supplies a default constructor for a class?

What will happen if an exception is not caught ?

What are the different ways in which a thread can enter into waiting state?

What is a ResourceBundle class?

What is numeric promotion?

What is the difference between the prefix and postfix forms of the ++ operator?

What is the difference between a switch statement and an if statement?

What is hashCode?

What is the difference between RandomAccessFile and File?

What is the difference among JVM Spec, JVM Implementation, JVM Runtime ?

What is the difference between Hashtable and HashMap ?

Why java is said to be pass-by-value ?

What do you mean by immutable ? How to create an immutable object ?

What is a weak reference ?

What is object cloning?

What is object pooling?

What is the disadvantage of garbage collection?

What are tag interfaces?

What are the restrictions placed on static method ?

What is JIT?

What is the Locale class?

What is the difference between URL and URLConnection?

What are the two important TCP Socket classes?

Strings are immutable. But String s=\"Hello\"; String s1=s+\"World\" returns HelloWorld how ?

What is classpath?

What is path?

What is java collections?

Can we compile a java program without main?

What is static initializer block? What is its use?

How does a try statement determine which catch clause should be used to handle an exception?

If a class doesn\'t have any constructors, what will happen?

What will happen if a thread cannot acquire a lock on an object?

What will happen if you are invoking a thread's interrupt method while the thread is waiting or sleeping?

What is coupling?

How will you define an interface?

How will you define an abstract class?

What is a JVM heap?

What is daemon thread?

What is a green thread?

What is volatile variable?

What is diamond problem?

How many JVM's we can run in a system?

Why ArrayList is faster than Vector?

What is the security mechnaism used in java?

What is phantom memory?

What is reflection?

What are the differences between JIT and HotSpot?

How would you implement a thread pool?

What is the difference between throw and throws clause?

What is the difference between Comparable and Comparator ?

What is the difference between List, Set and Map?

What is the difference between Exception and Error ?

What is meant by Open Source ?

How do you send data from an applet to Servlet ? What are the steps involved in it ?

What are the different inner classes types?

What is Nested top-level classes?

What is Member classes?

Can a top level class be private or protected?

How will you invoke any external process in Java?

What is composition?

What is aggregation?

What are the methods in Object?

What is the relationship between synchronized and volatile keyword?

What factors are used to decide using synchronized or volatile?

What are the drawbacks of inheritance?

What are the restrictions placed on the values of each case of a switch statement?

If aaaa is an array then why aaaa.length why not aaaa.length()?

What is dynamic typing?

What is static typig?

What is HashMap and Map?

What is an Object and how do you allocate memory to it?

What is UNICODE?

What is a stream and what are the types of Streams and classes of the Streams?

What is the difference between TCP/IP and UDP?

What is Inter-Thread communication?.

What is a thread group?

Why is UTFDataFormatException thrown by DataOutputStream.writeUTF() when serializing a String?

Why is OutOfMemoryError thrown after writing a large number of objects into an ObjectOutputStream?

How can I get the serialVersionUID of a class?

What is output of following code package r4r.co.in.core.java; public class HelloWorld { static int i = 0; public static void main(String args[]) { new HelloWorld(); } static { i = 10; System.out.println(i); } }

What is output of following code package r4r.co.in.core.java; public class HelloWorld { int i = 0; public static void main(String args[]) { System.out.println(i); new HelloWorld(); } static { int i; i = 10; System.out.println(i); } }

What is output of following code package r4r.co.in.core.java; public class HelloWorld { int i = 0; public static void main(String args[]) { System.out.println(i); new HelloWorld(); } static { static int i; i = 10; System.out.println(i); } }

What is output of following code package r4r.co.in.core.java; public class HelloWorld { int i = 0; public static void main(String args[]) { System.out.println(i); new HelloWorld(); } static { final static int i=0; i = 10; System.out.println(i); } }

What is output of following code package r4r.co.in.core.java; public class HelloWorld { static int i = 0; public static void main(String args[]) { System.out.println(i); new HelloWorld(); } static { final int i=0; i = 10; System.out.println(i); } }

What is output of following code package r4r.co.in.core.java; public class HelloWorld { static int i = 0; public static void main(String args[]) { System.out.println(i); new HelloWorld(); } static { static final int i=0; i = 10; System.out.println(i); } }

What is output of following code package r4r.co.in.core.java; public class HelloWorld { static int i = 0; public static void main(String args[]) { System.out.println(i); new HelloWorld(); } static { static int i=0; i = 10; System.out.println(i); } }

What is output of following code package r4r.co.in.core.java; public class HelloWorld { static int i = 0; public static void main(String args[]) { System.out.println(i); display(); } void display(){ i=90; System.out.println(i); } }

What is output of following code package r4r.co.in.core.java; public class HelloWorld { static int i = 0; public static void main(String args[]) { System.out.println(i); display(); } static void display(){ i=90; System.out.println(i); } }

What is output of following code package r4r.co.in.core.java; public class HelloWorld { static int i = 0; public static void main(String args[]) { System.out.println(i); display(); } static void display(){ int i=0; i=90; System.out.println(i); } }

What is output of following code package r4r.co.in.core.java; public class HelloWorld { static int i = 0; public static void main(String args[]) { System.out.println(i); display(); HelloWorld h=new HelloWorld(); h.display(); } static void display(){ int i=0; i=90; System.out.println(i); } }

What is output of following code package r4r.co.in.core.java; public class HelloWorld { static int i = 0; public static void main(String args[]) { System.out.println(i); HelloWorld h=new HelloWorld(); h.display(); } void display(){ int i=0; i=90; System.out.println(i); } }

What is output of following code package r4r.co.in.core.java; public class HelloWorld { static int i = 0; public static void main(String args[]) { System.out.println(i); display(); HelloWorld h=new HelloWorld(); h.display(); } void display(){ int i=0; i=90; System.out.println(i); } }

What is \'this\' ?

What is thread ?

What is throw ?

What is throws ?

What is transaction ?

What is transient ?

What is try ?

What is type ?

What is variable ?

What is void ?

What is volatile ?

What is while ?

What is wrapper ?

What is class method ?

What is class variable ?

What is constructor ?

What is this?

What is WAR file ?

What is the mean of Utility Classes?

Can a java source file hava more than one public classes?

What invokes a thread�s run() method?

What are the advantages of Spring framework?

What are features of Spring ?

What are the various steps involved in a Spring beans life cycle?

What do you mean by bean wiring in Spring container?

How do add a bean in spring application?

What is XMLBeanFactory in Spring framework?

What are singleton beans and how can you create prototype beans?

How can you reference a bean from another bean in Spring?

What is inner bean in Spring fremawork?

How will you handle the ambiguities of autowiring in Spring?

How will you wire a string value to a property whose type is a non-string?

What is throws advice in Spring?

Explain about PreparedStatementCreator?

What are the benefits of the Spring Framework transaction management ?

public class Test { static boolean XYZ(char a) { System.out.print(a); return true; } public static void main(String args[]) { int i=0; for(XYZ(\'P\'); XYZ(\'Q\')&&(i<2); XYZ(\'R\')) { i++; XYZ(\'S\'); } } }

What is right to way to declare array of primitives?

Variable Declarations

Instance Variables

Local (Automatic/Stack/Method) Variables

Final Variables

Transient Variables

Volatile Variables

Static Variables and Methods

Accessing Static Methods and Variables

Declaration Rules

Source File Structure

Using Import Statements

Formatting the main() Method

Interface Implementation

Declaring an Interface

Declaring Interface Constants

Implementing an Interface

How does the UNIX system identify user?

please guide me to sites which provide free source codes and tutorials in java

How to Create exe file of java application

what are responsibilities of a struts action class?which responsibility is view related aspect of boundary component?Does it provide any facilities for separating these view related aspects for the controller related action classes?

) The new operator creates a single instance named class and returns a reference to that object. what does this mean

How to implement log base 2(n) Function in java ?

when we decleard any data type as static thenwhy it do not take memory.for ex...static int

What is difference between jdk1.4 and jdk1.5?