How would you make a copy of an entire Java object with its state?

Java Interview Questions and Answers (part 3)

(Continued from previous question...)

457. How would you make a copy of an entire Java object with its state?

Have this class implement Cloneable interface and call its method clone().

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Other Interview Questions

• Why isn't there operator overloading?
• What does it mean that a method or field is "static"?
• Why do threads block on I/O?
• What is synchronization and why is it important?
• Is null a keyword?
• Which characters may be used as the second character of an identifier,but not as the first character of an identifier?
• Whats the difference between notify() and notifyAll()?
• Why can't I say just abs() or sin() instead of Math.abs() and Math.sin()?
• Why are there no global variables in Java?
• What does it mean that a class or member is final?
• What does it mean that a method or class is abstract?
• What is the main difference between Java platform and other platforms?
• What is the Java Virtual Machine?
• What is the Java API?
• What is the package?
• What is native code?
• Explain the user defined Exceptions?
• Is Java code slower than native code?
• Can main() method be overloaded?
• What is the serialization?
• Explain the new Features of JDBC 2.0 Core API?
• Explain garbage collection?
• How you can force the garbage collection?
• What is OOPS?
• Describe the principles of OOPS.
• Explain the Encapsulation principle.
• Explain the Inheritance principle.
• Explain the Polymorphism principle.
• Explain the different forms of Polymorphism.
• What are Access Specifiers available in Java?
• Describe the wrapper classes in Java.
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• Why are the interfaces more flexible than abstract classes?
• What are new language features in J2SE 5.0?
• What is covariant return type?
• What is the result of the following statement?
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• What will be the output on executing the following code...
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• What is JIT?
• What are ClassLoaders?
• What is Service Locator pattern?
• What is Session Facade pattern?
• What is Data Access Object pattern?
• How can we make a class Singleton
• Can we make an EJB singleton?
• How is static Synchronization different form non-static synchronization?
• What are class members and Instance members?
• Name few Garbage collection algorithms?
• Does Java pass by Value or reference?
• Why Thread is faster compare to process?
• When and How is an object considered as Garbage by a GC?
• Can we force Garbage collection?
• What are generations in Garbage Collection terminolgy? What is its relevance?
• What is a Throughput Collector?
• When to Use the Throughput Collector?
• What is AggressiveHeap?
• What is a Concurrent Low Pause Collector?
• When to Use the Concurrent Low Pause Collector?
• What is Incremental Low Pause Collector?
• When to Use the Incremental Low Pause Collector?
• How do you enable the concurrent garbage collector on Sun's JVM?
• What is a platform?
• What is transient variable?
• How to make a class or a bean serializable?
• What restrictions are placed on method overloading?
• Name Container classes.
• What is the List interface?
• What is the difference between a Scrollbar and a ScrollPane?
• What is tunnelling?
• What is meant by "Abstract Interface"?
• Can Java code be compiled to machine dependent executable file?
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• What method is used to specify a container's layout?
• Which containers use a FlowLayout as their default layout?
• What state does a thread enter when it terminates its processing?
• What is the Collections API?
• What is the List interface?
• Is sizeof a keyword?
• Which class is the superclass for every class.
• Which Container method is used to cause a container to be laid out and redisplayed?
• What's the difference between a queue and a stack?
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• What comes to mind when you hear about a young generation in Java?
• What comes to mind when someone mentions a shallow copy in Java?
• If you're overriding the method equals() of an object, which other method you might also consider?
• You are planning to do an indexed search in a list of objects. Which of the two Java collections should you use: ArrayList or LinkedList?
• How would you make a copy of an entire Java object with its state?
• How can you minimize the need of garbage collection and make the memory use more effective?
• There are two classes: A and B. The class B need to inform a class A when some important event has happened. What Java technique would you use to implement it?
• What access level do you need to specify in the class declaration to ensure that only classes from the same directory can access it?
• What is the difference between an Interface and an Abstract class?
• What is the purpose of garbage collection in Java, and when is it used?
• Describe synchronization in respect to multithreading.
• Explain different way of using thread?
• What are pass by reference and passby value?
• What is HashMap and Map?
• Difference between HashMap and HashTable?
• Difference between Vector and ArrayList?
• Difference between Swing and Awt?
• 470. What is the difference between a constructor and a method?
• What is an Iterator?
• 472. State the significance of public, private, protected, default modifiers both singly and in combination and state the effect of package relationships on declared items qualified by these modifiers.
• What is an abstract class?
• What is static in java?
• What is final?
• What if the main method is declared as private?
• What if the static modifier is removed from the signature of the main method?
• What if I write static public void instead of public static void?
• What if I do not provide the String array as the argument to the method?
• What is the first argument of the String array in main method?
• If I do not provide any arguments on the command line, then the String array of Main method will be empty or null?
• How can one prove that the array is not null but empty using one line of code?
• What environment variables do I need to set on my machine in order to be able to run Java programs?
• Can an application have multiple classes having main method?
• 485. Can I have multiple main methods in the same class?
• Do I need to import java.lang package any time? Why ?
• Can I import same package/class twice? Will the JVM load the package twice at runtime?
• What are Checked and UnChecked Exception?
• What is Overriding?
• What are different types of inner classes?
• Are the imports checked for validity at compile time? e.g. will the code containing an import such as java.lang.ABCD compile?
• Does importing a package imports the subpackages as well? e.g. Does importing com.MyTest.* also import com.MyTest.UnitTests.*?
• What is the difference between declaring a variable and defining a variable?
• What is the default value of an object reference declared as an instance variable?
• Can a top level class be private or protected?
• What type of parameter passing does Java support?
• Primitive data types are passed by reference or pass by value?
• Objects are passed by value or by reference?
• What is serialization?
• How do I serialize an object to a file?
• Which methods of Serializable interface should I implement?
• How can I customize the seralization process? i.e. how can one have a control over the serialization process?
• What is the common usage of serialization?
• What is Externalizable interface?
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• What one should take care of while serializing the object?
• 507. What happens to the static fields of a class during serialization?
• 508. Does Java provide any construct to find out the size of an object?
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• 511. Why do we need wrapper classes?
• 512. What are checked exceptions?
• What are runtime exceptions?
• What is the difference between error and an exception?
• How to create custom exceptions?
• If I want an object of my class to be thrown as an exception object, what should I do?
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