Chapter 7.1.4 : The finally Keyword

The finally keyword is used to create a block of code that follows a try block. A finally block of code always executes, whether or not an exception has occurred.

Using a finally block allows you to run any cleanup-type statements that you want to execute, no matter what happens in the protected code.

A finally block appears at the end of the catch blocks and has the following syntax:

try

{

   //Protected code

}catch(ExceptionType1 e1)

{

   //Catch block

}catch(ExceptionType2 e2)

{

   //Catch block

}catch(ExceptionType3 e3)

{

   //Catch block

}finally

{

   //The finally block always executes.

}

Example:

public class ExcepTest{

   public static void main(String args[]){

      int a[] = new int[2];

      try{

         System.out.println("Access element three :" + a[3]);

      }catch(ArrayIndexOutOfBoundsException e){

         System.out.println("Exception thrown  :" + e);

      }

      finally{

         a[0] = 6;

         System.out.println("First element value: " +a[0]);

         System.out.println("The finally statement is executed");

      }

   }

}

This would produce the following result:

Exception thrown  :java.lang.ArrayIndexOutOfBoundsException: 3

First element value: 6

The finally statement is executed

Note the following:

·         A catch clause cannot exist without a try statement.

·         It is not compulsory to have finally clauses when ever a try/catch block is present.

·         The try block cannot be present without either catch clause or finally clause.

·         Any code cannot be present in between the try, catch, finally blocks.