Java Developer Interview Preparation Guide
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Java Developer Frequently Asked Questions by expert members with experience in Java Developer. These questions and answers will help you strengthen your technical skills, prepare for the new job test and quickly revise the concepts

63 Java Developer Questions and Answers:

1 :: How Observer and Observable used in Java Programming?

Objects that subclass the Observable class maintain a list of observers. When an Observable object is updated it invokes the update() method of each of its observers to notify the observers that it has changed state. The Observer interface is implemented by objects that observe Observable objects.
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2 :: Described synchronization and why is it important in Java Programming?

With respect to multithreading, synchronization is the capability to control the access of multiple threads to shared resources. Without synchronization, it is possible for one thread to modify a shared object while another thread is in the process of using or updating that object's value. This often causes dirty data and leads to significant errors.
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3 :: Described synchronized methods and synchronized statements in Java Programming?

Synchronized methods are methods that are used to control access to an object. A thread only executes a synchronized method after it has acquired the lock for the method's object or class. Synchronized statements are similar to synchronized methods. A synchronized statement can only be executed after a thread has acquired the lock for the object or class referenced in the synchronized statement.
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4 :: Which three ways in which a thread can enter the waiting state in Java Programming?

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.
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5 :: Define preferred size of a component in Java Programming?

The preferred size of a component is the minimum component size that will allow the component to display normally.
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6 :: What's new with stop(), suspend() and resume() methods in JDK 1.2?

The stop(), suspend() and resume() methods have been deprecated in JDK 1.2.
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7 :: Described transient variable?

A transient variable is a variable that may not be serialized.
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8 :: Which containers use FlowLayout as their default layout in Java Programming?

The Panel and Applet classes use the FlowLayout as their default layout.
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9 :: Can a lock be acquired on class in Java Programming?

Yes, a lock can be acquired on a class. This lock is acquired on the class's Class object.
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10 :: Define Llist interface in Java Programming?

The List interface provides support for ordered collections of objects.
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