http://www.javatpoint.com/difference-between-final-finally-and-finalize

Final

Final is used to apply restrictions on class, method and variable. Final class can't be inherited, final method can't be overridden and final variable value can't be changed.

• final keyword is used with Class to make sure no other class can extend it, for example String class is final and we can’t extend it.

• We can use final keyword with methods to make sure child classes can’t override it.

• final keyword can be used with variables to make sure that it can be assigned only once. However the state of the variable can be changed, for example we can assign a final variable to an object only once but the object variables can change later on.

Java interface variables are by default final and static.

class FinalExample{  
public static void main(String[] args){  
final int x=100;  
x=200;//Compile Time Error  
}}

Finally

Finally is used to place important code, it will be executed whether exception is handled or not.

class FinallyExample{  
public static void main(String[] args){  
try{  
int x=300;  
}catch(Exception e){System.out.println(e);}  
finally{System.out.println("finally block is executed");}  
}}

Finalize

Finalize is used to perform clean up processing just before object is garbage collected.

class FinalizeExample{  
public void finalize(){System.out.println("finalize called");}  
public static void main(String[] args){  
FinalizeExample f1=new FinalizeExample();  
FinalizeExample f2=new FinalizeExample();  
f1=null;  
f2=null;  
System.gc();  
}}