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Which Container method is used to cause a container to be laid out and redisplayed
Validate()
Sandhya.Kishan
- Jul 13th, 2012
Validate() method is used to cause a container to be laid out and redisplayed in java programming.
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What method is invoked to cause an object to begin executing as a separate thread
The start() method of the Thread class is invoked to cause an object to begin executing asa separate thread.
Sandhya.Kishan
- Jul 13th, 2012
The start() method is invoked to cause an object to begin executing as a separate thread.
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Java Copy Command
Write the Java version of MS DOS Copy Command
Sandhya.Kishan
- Jul 13th, 2012
The command FileUtils.copyFile(fOrig, fDest); is similar to ms ds copy command.
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What happens when you invoke a thread's interrupt method while it issleeping or waiting
When a task's interrupt() method is executed, the task enters the ready state. The nexttime the task enters the running state, an InterruptedException is thrown.
Sandhya.Kishan
- Jul 14th, 2012
Java.lang.InterruptedException is called when we invoke a threads interrupt method while it is sleeping.
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What are three ways in which a thread can enter the waiting state
A thread can enter the waiting state by invoking its sleep() method, by blocking on I/O,by unsuccessfully attempting to acquire an object's lock, or by invoking an object's wait()method. It can also enter the waiting state by invoking its (deprecated) suspend() method.
Sandhya.Kishan
- Jul 14th, 2012
A thread can enter the waiting state by invoking wait() method, sleep() method and suspend() method.
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Can an unreachable object become reachable again
An unreachable object may become reachable again. This can happen when the object'sfinalize() method is invoked and the object performs an operation which causes it tobecome accessible to reachable objects.
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What happens if an exception is not caught
An uncaught exception results in the uncaughtException() method of the thread'sThreadGroup being invoked, which eventually results in the termination of the programin which it is thrown.
Sandhya.Kishan
- Jul 14th, 2012
When an exception is not caught by any method then the main method throws an exception and results in the termination of that method.
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How are this and super used
This is used to refer to the current object instance. super is used to refer to the variablesand methods of the superclass of the current object instance.
Sandhya.Kishan
- Jul 14th, 2012
Super() refers to the superclass of the class where the super keyword is currently being used.It is used to call the constructor of the superclass in the base class. eg: public class Class1{ public C...
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What are the drivers available?
Sandhya.Kishan
- Jul 16th, 2012
The drivers avaliable in jdbc are
Type 1: JDBC-ODBC Bridge driver (Bridge)
Type 2: Native-API/partly Java driver (Native)
Type 3: AllJava/Net-protocol driver (Middleware)
Type 4: All Java/Native-protocol driver (Pure) -
What class of exceptions are generated by the Java run-time system
The Java runtime system generates RuntimeException and Error exceptions.
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What classes of exceptions may be caught by a catch clause
A catch clause can catch any exception that may be assigned to the Throwable type. Thisincludes the Errorand Exception types.
Sandhya.Kishan
- Jul 21st, 2012
An exception which may be assigned to the Throwable type including the Error and Exception types are caught by catch clause.
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How are the elements of a CardLayout organized
The elements of a CardLayout are stacked, one on top of the other, like a deck of cards.
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For which statements does it make sense to use a label
The only statements for which it makes sense to use a label are those statements that canenclose a break orcontinue statement.
Sandhya.Kishan
- Jul 21st, 2012
For statements which are enclosed by a break or a continue statement makes sense to use a label statement.
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What modifiers may be used with an interface declaration
An interface may be declared as public or abstract.
Sandhya.Kishan
- Jul 23rd, 2012
The public and abstract modifiers can be used with an interface declaration.
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What modifiers can be used with a local inner class
A local inner class may be final or abstract.
Sandhya.Kishan
- Jul 23rd, 2012
The public,private, abstract, final, protected, strictfp and static modifiers can be used with a local inner class.
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What are the legal operands of the instanceof operator
The left operand is an object reference or null value and the right operand is a class,interface, or array type.
Sandhya.Kishan
- Jul 23rd, 2012
The legal operands of instance of operator are
1. Left operand which is an object reference.
2. Right operand which can be a class or an interface.
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What must a class do to implement an interface
It must provide all of the methods in the interface and identify the interface in itsimplements clause.
Sandhya.Kishan
- Jul 23rd, 2012
A class should provides the definition to all the methods declared in the interface to implement an interface.
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What classes of exceptions may be thrown by a throw statement
A throw statement may throw any expression that may be assigned to the Throwabletype.
Sandhya.Kishan
- Jul 24th, 2012
Exceptions which are assigned Throwable Type are thrown by a throw statement.
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What is the purpose of finalization
The purpose of finalization is to give an unreachable object the opportunity to performany cleanupprocessing before the object is garbage collected.
Sandhya.Kishan
- Jul 24th, 2012
The purpose of finalization is to provide opportunity to an object which is unreachable to perform any cleanup process . This activity is done before the object is garbage collected.Finalization is used to invoke finalized() method
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What is the purpose of the finally clause of a try-catch-finally statement
The finally clause is used to provide the capability to execute code no matter whether ornot an exception isthrown or caught.
Sandhya.Kishan
- Jul 24th, 2012
The purpose is that,when an exception is caught during program execution,code written in finally clause will be executed ,irrespective of what type of error has occurred.
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