Exception Handling

• Exception


  An event that occurs during the execution of a program that disrupts the normal flow of instructions
• Exceptionhandling


  The process used to change the normal flow of code execution if a specified exception occurs
• Checked Exceptions


  • ClassNotFoundException
  • IllegalAccessException
  • InstantiationException
  • NoSuchMethodException
• ClassNotFoundException


  The class is not found
• IllegalAccessException


  Access to a class is denied
• InstantiationException


  Attempt to create an object of an abstract class or an interface
• NoSuchMethodException


  A requested method does not exist
• Unchecked Exceptions


  • ArithmeticException
  • ArrayIndexOutOfBoundsException
  • ArrayStoreException
  • InputMismatchException
  • NullPointerException
  • NumberFormatException
  • StringIndexOutOfBoundsException
• ArithmeticException


  Arithmetic error, such as an integer divided by 0
• ArrayIndexOutOfBoundsException


  Accessing an invalid index of the array
• ArrayStoreException


  Assigning a value to an array index that does not match the expected data type
• InputMismatchException


  Entering a value that does not match the expected data type
• NullPointerException


  Invalid use of a null reference
• NumberFormatException


  Invalid conversion of a string to a numeric format
• StringIndexOutOfBoundsException


  Accessing an invalid index (character) of a string
• try block


  A block of code that might throw an exception that can be handled by a matching catch block
• catch block


  A segment of code that can handle an exception that might be thrown by the try block that precedes it
• getMessage()


  A method that can be used to determine Java's message about the exception
• finally block


  Contains statements which are executed whether or not an exception is thrown
• user-defined exception


  Created by extending the Exception class
• throw statement


  Sends an exception out of a block or a method so it can be handled elsewhere