Java inheritance does not allow inherited classes to be immutable class final class

Instance:

 Public Final classaddress{Private FinalString Detail; Private FinalString postcode; //initializing two instance properties in a constructor method     PublicAddress () { This. Detail = "";  This. Postcode = ""; }     PublicAddress (String detail, string postcode) { This. Detail =detail;  This. Postcode =postcode; }    //provides getter methods for only two instance properties     PublicString Getdetail () {return  This. Detail; }     PublicString Getpostcode () {return  This. Postcode; }    //override the Equals method to determine whether two objects are equal.      Public Booleanequals (Object obj) {if(objinstanceofAddress) {Address ad=(Address) obj; if( This. Getdetail (). Equals (Ad.getdetail ()) && This. Getpostcode (). Equals (Ad.getpostcode ())) {                return true; }        }        return false; }     Public inthashcode () {returnDetail.hashcode () +Postcode.hashcode (); } Public Static voidMain (String args[]) {Address a=NewAddress (); Address b=NewAddress ("ABCD", "EFGH"); System.out.println ("A:" +a.getdetail () +a.getpostcode () +A.hashcode ()); System.out.println ("B:" +b.getdetail () +b.getpostcode () +B.hashcode ()); System.out.println (A.equals (b));}}

Results:

Cause Analysis:

in Final the declared method does not allow overwriting, nor does it allow changes, so using final, we can devise a special kind of " Read-only " of the " Immutable Classes " . Create " Immutable Classes " Object , the properties of this object cannot be changed . and you cannot derive a new subclass from this class. String is a code examples of types.   Immutable " class " the role ? 1, can be conveniently and safely used in multi-threaded environment, 2, access to them can not be locked, thus providing high performance.

Java inheritance does not allow inherited classes to be immutable class final class