Saturday, December 12

Java Fundamental-V

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1. What is the use of preparedstatement?
Preparedstatements are precompiled statements. It is mainly used to speed up the process of inserting/updating/deleting especially when there is a bulk processing.


2. What is callable statement? Tell me the way to get the callable statement?
Callablestatements are used to invoke the stored procedures. You can obtain the callablestatement from Connection using the following methods prepareCall(String sql) prepareCall(String sql, int resultSetType, int resultSetConcurrency)


3. In a statement, I am executing a batch. What is the result of the execution?
It returns the int array. The array contains the affected row count in the corresponding index of the SQL.


4. Can a abstract method have the static qualifier?
No


5.. What are the different types of qualifier and what is the default qualifier?
public, protected, private, package (default)


6. What is the super class of Hashtable?
Dictionary


7. What is a lightweight component?
Lightweight components are the one which doesn’t go with the native call to obtain the graphical units. They share their parent component graphical units to render them. Example, Swing components


8. What is a heavyweight component?
For every paint call, there will be a native call to get the graphical units. Example, AWT.


9. What is an applet?
Applet is a program which can get downloaded into a client environment and start executing there.


10. What do you mean by a Classloader?
Classloader is the one which loads the classes into the JVM.


11. What are the implicit packages that need not get imported into a class file?
java.lang


12. What is the difference between lightweight and heavyweight component?
Lightweight components reuses its parents graphical units. Heavyweight components goes with the native graphical unit for every component. Lightweight components are faster than the heavyweight components.


13. What are the ways in which you can instantiate a thread?
Using Thread class By implementing the Runnable interface and giving that handle to the Thread class.


14. What are the states of a thread?
1. New 2. Runnable 3. Not Runnable 4. Dead


15. What is a socket?
A socket is an endpoint for communication between two machines.


16. How will you establish the connection between the servlet and an applet?
Using the URL, I will create the connection URL. Then by openConnection method of the URL, I will establish the connection, through which I can be able to exchange data.


17. What are the threads will start, when you start the java program?
Finalizer, Main, Reference Handler, Signal Dispatcher

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