Java Finally Block

Last Updated: 06 March, 2023

Finally is a keyword that is used to create a block that contains a set of crucial statements. Finally block is attached to try-catch blocks.

finally block is always executed, whether an exception occurs or not. Therefore, it contains all the necessary statements that need to be executed, such as closing a connection or closing a file, etc.

Syntax:

try { // Statements that may cause an exception } catch { // Statements that handle exception } finally { // Statements to be executed whether exception happens or not }

Use a try-with-resources statement instead of a finally block when closing a file or otherwise recovering resources. The try-with-resources statement automatically releases system resources when no longer needed.

Example 1 : When an exception does not occur

public class FinallyBlockExample1 { public static void main(String[] args) { try { System.out.println("Executing try block..."); String studentName = "Mithilesh Mtariya"; System.out.println("Length: " + studentName.length()); } catch (NullPointerException e) { System.out.println("Executing catch block..."); System.out.println(e); } // executed regardless of exception occurred or not finally { System.out.println("Executing finally block..."); } System.out.println("Rest of the code after try/catch blocks... "); } }

Output

Executing try block...
Length: 17
Executing finally block...
Rest of the code after try/catch blocks...

Example 2 : When an exception occurs and is handled by the catch block

public class FinallyBlockExample2 { public static void main(String[] args) { try { System.out.println("Executing try block..."); String studentName = null; System.out.println("Length: " + studentName.length()); // throw Exception } catch (NullPointerException e) { System.out.println("Executing catch block..."); System.out.println("Exception occured: " + e); } // executed regardless of exception occurred or not finally { System.out.println("Executing finally block..."); } System.out.println("Rest of the code after try/catch blocks... "); } }

Output

Executing try block...
Executing catch block...
Exception occured: java.lang.NullPointerException
Executing finally block...
Rest of the code after try/catch blocks...

Example 3 : When an exception occur but not handled by the catch block

public class FinallyBlockExample3 { public static void main(String[] args) { try { System.out.println("Executing try block..."); int output = 100 / 0; // throw Exception System.out.println("output: " + output); } catch (NullPointerException e) { System.out.println("Executing catch block..."); System.out.println(e); } // executed regardless of exception occurred or not finally { System.out.println("Executing finally block..."); } System.out.println("Rest of the code after try/catch blocks... "); } }

Output

Executing try block...
Executing finally block...
Exception in thread "main" java.lang.ArithmeticException: / by zero at com.javabytechie.exceptionhandling.FinallyBlockExample3.main(FinallyBlockExample3.java:7)