final

final can be used to mark a variable "unchangeable"

private final String name = "foo";  //the reference name can never change

final can also make a method not "overrideable"

public final String toString() {  return "NULL"; }

final can also make a class not "inheritable". i.e. the class can not be subclassed.

public final class finalClass {...}
public class classNotAllowed extends finalClass {...} // Not allowed

finally

finally is used in a try/catch statement to execute code "always"

lock.lock();
try {
  //do stuff
} catch (SomeException se) {
  //handle se
} finally {
  lock.unlock(); //always executed, even if Exception or Error or se
}

Java 7 has a new try with resources statement that you can use to automatically close resources that explicitly or implicitly implement java.io.Closeable or java.lang.AutoCloseable

finalize

finalize is called when an object is garbage collected. You rarely need to override it. An example:

protected void finalize() {
  //free resources (e.g. unallocate memory)
  super.finalize();
}

final keyword

class

On a class it means you forbid to have a child class extending yours.

public final class finalClass

Attribute/Field

final MyObject value = new MyObject() means you won't be able to modify the instance of the object.

value = xxxx won't be allowed, but you still can modify the object itself value.field = "xxx";

Method When you use final on a method, that means you'll forbid child classes that extends your class to override this method.

public final void finalMethod()

It can also be used on arguments, that means you don't allow other to modify the instance of the object you give.

public void myMethod(final MyObject myObject)

The end user won't be able to do myObject = ...

Finally block

finally block has nothing to do with final, it's used when catching Exception to ensure a part of code will be ran, wherever there is an exception or not.

try { ...}
catch {} // Optional
finally { // Code that will be ran, exception or not being thrown}

Finalize method

It's called on every object when it's destroyed (usually garbage collected).