<< < … 18 19 20 21 22 23 24 25 26 27 > >>   Sort: Date

Can an application have multiple classes having main method?
Can an application have multiple classes having main method? Yes it is possible. While starting the application we mention the class name to be run. The JVM will look for the Main method only in the class whose name you have mentioned. Hence there is not conflict amongst the multiple classes having ...
2013-05-08, 2439👍, 0💬

How to make a class or a bean serializable?
How to make a class or a bean serializable? By implementing either the java.io.Serializable interface, or the java.io.Externalizable interface. As long as one class in a class's inheritance hierarchy implements Serializable or Externalizable, that class is serializable.
2013-04-01, 2439👍, 0💬

Difference between Swing and Awt?
Difference between Swing and Awt? AWT are heavy-weight componenets. Swings are light-weight components. Hence swing works faster than AWT.
2013-04-26, 2438👍, 0💬

What is the difference between a while statement and a do statement?
What is the difference between a while statement and a do statement? A while statement checks at the beginning of a loop to see whether the next loop iteration should occur. A do statement checks at the end of a loop to see whether the next iteration of a loop should occur. The do statement will alw...
2012-12-07, 2437👍, 0💬

What is an Iterator?
What is an Iterator? Some of the collection classes provide traversal of their contents via a java.util.Iterator interface. This interface allows you to walk through a collection of objects, operating on each object in turn. Remember when using Iterators that they contain a snapshot of the collectio...
2013-04-29, 2436👍, 0💬

What are three ways in which a thread can enter the waiting state?
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 invok...
2013-01-17, 2436👍, 0💬

What is a void return type?
What is a void return type? A void return type indicates that a method does not return a value.
2013-01-07, 2436👍, 0💬

What is synchronization and why is it important?
What is synchronization and why is it important? 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...
2013-02-12, 2435👍, 0💬

What class of exceptions are generated by the Java run-time system?
What class of exceptions are generated by the Java run-time system? The Java runtime system generates RuntimeException and Error exceptions.
2012-12-24, 2435👍, 0💬

How do I serialize an object to a file?
How do I serialize an object to a file? The class whose instances are to be serialized should implement an interface Serializable. Then you pass the instance to the ObjectOutputStream which is connected to a fileoutputstream. This will save the object to a file.
2013-05-20, 2431👍, 0💬

What is the List interface?
What is the List interface? The List interface provides support for ordered collections of objects.
2013-04-02, 2431👍, 0💬

When and How is an object considered as Garbage by a GC?
When and How is an object considered as Garbage by a GC? An object is considered garbage when it can no longer be reached from any pointer in the running program. The most straightforward garbage collection algorithms simply iterate over every reachable object. Any objects left over are then conside...
2013-03-21, 2431👍, 0💬

Which Math method is used to calculate the absolute value of a number?
Which Math method is used to calculate the absolute value of a number? The abs() method is used to calculate absolute values.
2012-12-13, 2431👍, 0💬

What happens to the static fields of a class during serialization?
What happens to the static fields of a class during serialization? There are three exceptions in which serialization doesnot necessarily read and write to the stream. These are 1. Serialization ignores static fields, because they are not part of ay particular state state. 2. Base class fields are on...
2013-05-23, 2429👍, 0💬

What is a Java package and how is it used?
What is a Java package and how is it used? A Java package is a naming context for classes and interfaces. A package is used to create a separate name space for groups of classes and interfaces. Packages are also used to organize related classes and interfaces into a single API unit and to control ac...
2013-01-24, 2429👍, 0💬

WWhat is the difference between static and non-static variables?
WWhat is the difference between static and non-static variables? A static variable is associated with the class as a whole rather than with specific instances of a class. Non-static variables take on unique values with each object instance.
2013-06-12, 2428👍, 0💬

What is the Map interface?
What is the Map interface? The Map interface replaces the JDK 1.1 Dictionary class and is used associate keys with values.
2012-11-26, 2427👍, 0💬

Explain the Encapsulation principle
Explain the Encapsulation principle Encapsulation is a process of binding or wrapping the data and the codes that operates on the data into a single entity. This keeps the data safe from outside interface and misuse. One way to think about encapsulation is as a protective wrapper that prevents code ...
2013-02-28, 2424👍, 0💬

Can we make an EJB singleton?
Can we make an EJB singleton? This is a debatable question, and for every answer we propose there can be contradictions. I propose 2 solutions fo the same. Remember that EJB's are distributed componenets and can be deployed on different JVM's in a Distributed environment i) Follow the steps as given...
2013-03-18, 2423👍, 0💬

What restrictions are placed on method overriding?
What restrictions are placed on method overriding? Overridden methods must have the same name, argument list, and return type. The overriding method may not limit the access of the method it overrides. The overriding method may not throw any exceptions that may not be thrown by the overridden method...
2013-01-14, 2423👍, 0💬

What one should take care of while serializing the object?
What one should take care of while serializing the object? One should make sure that all the included objects are also serializable. If any of the objects is not serializable then it throws a NotSerializableException.
2013-05-23, 2422👍, 0💬

What interface must an object implement before it can be written to a stream as an object?
What interface must an object implement before it can be written to a stream as an object? An object must implement the Serializable or Externalizable interface before it can be written to a stream as an object.
2013-01-10, 2421👍, 0💬

What is HashMap and Map?
What is HashMap and Map? Map is Interface and Hashmap is class that implements that.
2013-04-25, 2418👍, 0💬

The superclass constructor runs before the subclass constructor ...
The superclass constructor runs before the subclass constructor ... The superclass constructor runs before the subclass constructor. The subclass's version of the overridable method will be invoked before the subclass's constructor has been invoked. If the subclass's overridable method depends on th...
2013-03-06, 2417👍, 0💬

<< < … 18 19 20 21 22 23 24 25 26 27 > >>   Sort: Date