Java: What is the difference between final, finally, and finalize in Java?

final — keyword. finally — block. finalize — method (deprecated).

final:

• Keyword.
• For variables, methods, classes.
• Cannot change.

1final int x = 10;  // Cannot change
2x = 20;  // Error!
3
4final class Person {}  // Cannot extend
5// class Student extends Person {}  // Error!

finally:

• Block after try-catch.
• Always executes.
• For cleanup.

1try {
2    // Code
3} catch (Exception e) {
4    // Handle
5} finally {
6    // Always executes
7    // Cleanup
8}

finalize():

• Method in Object class.
• Called by GC before cleanup.
• Deprecated in Java 9.
• Unreliable.

1protected void finalize() {
2    // Cleanup
3}

Best practice:

• Use try-with-resources instead of finally.