In Java what purpose do the keywords final finally and finalize fulfil

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In Java  what purpose do the keywords final  finally and finalize fulfil

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final      final is a keyword  The variable decleared as final should be     initialized only once and cannot be changed  Java classes     declared as final cannot be extended  Methods declared as final     cannot be overridden   finally      finally is a block  The finally block always executes when the     try block exits  This ensures that the finally block is executed     even if an unexpected exception occurs  But finally is useful for     more than just exception handling - it allows the programmer to     avoid having cleanup code accidentally bypassed by a return      continue  or break  Putting cleanup code in a finally block is     always a good practice  even when no exceptions are anticipated   finalize      finalize is a method  Before an object is garbage collected  the     runtime system calls its finalize   method  You can write system     resources release code in finalize   method before getting garbage     collected

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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

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The meaning of final in java is  -applied to a variable means that the respective variable once initialized can no longer be modified  private final double numer   12    If you try to modify this value  you will get an error   -applied to a method means that the respective method can t be override   public final void displayMsg                 System out println  I m in Base class - displayMsg              But final method can be inherited because final keyword restricts the redefinition of the method   -applied to a class means that the respective class can t be extended   class Base        public void displayMsg                 System out println  I m in Base class - displayMsg                The meaning of finally is    class TestFinallyBlock      public static void main String args         try       int data 25 5       System out println data             catch NullPointerException e  System out println e        finally System out println  finally block is always executed         System out println  rest of the code                    in this exemple even if the try-catch is executed or not  what is inside of finally will always be executed  The meaning of finalize   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             before calling the Garbage Collector

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1  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 variables are initialized at the time of creation except in case of blank final variable which is initialized in Constructor        Final is a keyword   2  Finally       Finally is used for exception handling along with try and catch        It will be executed whether exception is handled or not        This block is used to close the resources like database connection  I O resources        Finally is a block   3  Finalize       Finalize is called by Garbage collection thread just before collecting eligible objects to perform clean up processing        This is the last chance for object to perform any clean-up but since it   s not guaranteed that whether finalize    will be called  its bad practice to keep resource till finalize call        Finalize is a method

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Final  denotes that something cannot be changed  You usually want to use this on static variables that will hold the same value throughout the life of your program   Finally  is used in conjunction with a try catch block  Anything inside of the  finally  clause will be executed regardless of if the code in the  try  block throws an exception or not   Finalize  is called by the JVM before an object is about to be garbage collected

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The final keyword is used to declare constants   final int FILE TYPE   3    The finally keyword is used in a try catch statement to specify a block of code to execute regardless of thrown exceptions   try       stuff   catch Exception e        do stuff   finally       this is always run     And finally  haha   finalize im not entirely sure is a keyword  but there is a finalize   function in the Object class

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http   allu wordpress com 2006 11 08 difference-between-final-finally-and-finalize   final     constant declaration  finally     The finally block always executes when the try block exits  except System exit 0  call  This ensures that the finally block is executed even if an unexpected exception occurs  But finally is useful for more than just exception handling     it allows the programmer to avoid having cleanup code accidentally bypassed by a return  continue  or break  Putting cleanup code in a finally block is always a good practice  even when no exceptions are anticipated  finalize       method helps in garbage collection  A method that is invoked before an object is discarded by the garbage collector  allowing it to clean up its state  Should not be used to release non-memory resources like file handles  sockets  database connections etc because Java has only a finite number of these resources and you do not know when the garbage collection is going to kick in to release these non-memory resources through the finalize   method   Did you try searching on google  and need clarification for an explanation

[java] In Java, what purpose do the keywords `final`, `finally` and `finalize` fulfil?

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