Advanced Java Questions and Answer for Interview
151. What is the difference between the File and RandomAccessFile classes?
File class encapsulates the files and directories of the local file system.
RandomAccessFile class provides the methods needed to directly access data contained in any part of a file.
152. What happens when you add a double value to a String?
The result is a
153. What is your platform's default character encoding?
If you are running Java on English Windows platforms, it is probably Cp1252. If you are running Java on English Solaris platforms, it is most likely 8859_1.
154. Which package is always imported by default?
java.lang package is always imported by default.
155. What interface must an object implement before it can be written to a stream as an object?
An object must implement the
Externalizable interface before it can be written to a stream as an object.
156. How are this and super used?
this is used to refer to the current object instance.
super is used to refer to the variables and methods of the superclass of the current object instance.
157. What is a compilation unit?
A compilation unit is a Java source code file.
158. What interface is extended by AWT event listeners?
All AWT event listeners extend the
159. 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.
160. How can a dead thread be restarted?
A dead thread cannot be restarted.