Where is stored captured variable in Java? -

i'm trying understand concept of captured variable in java.

i found quite detailed article it: http://www.devcodenote.com/2015/04/variable-capture-in-java.html

and i'm not sure bytecode part:

similarly, accessing local variables of enclosing method, hidden copy of variable made , kept in inner class file accesses variable.

how can saved class file (during compilation), when final primitive values may not known in compile time?

for example:

void foo(int x){     final int y = 10 + x;      class localclass(){         localclass(){             system.out.println(y);  // works fine         }     } } 

if author wrong, local variables copied localclass's space in method area in runtime?

the author seems referring fact captured variables translated fields of local/anonymous class.

if disasemble localclass can see (where main name of enclosing class):

class main$1localclass {   final int val$y;    final main this$0;    main$1localclass();     code:        0: aload_0        1: aload_1        2: putfield      #1                  // field this$0:lmain;        5: aload_0        6: iload_2        7: putfield      #2                  // field val$y:i       10: aload_0       11: invokespecial #3                  // method java/lang/object."<init>":()v       14: getstatic     #4                  // field java/lang/system.out:ljava/io/printstream;       17: aload_0       18: getfield      #2                  // field val$y:i       21: invokevirtual #5                  // method java/io/printstream.println:(i)v       24: return } 

the first field local variable y, , second field reference enclosing instance. furthermore, these values passed constructor of local class implicitly.

essentially localclass looks this:

class localclass {     final int val$y;     final main this$0;      localclass(main arg1, int arg2) {         this.this$0 = arg1; // bytecode 1-2         this.val$y = arg2; // bytecode 5-7         super(); // bytecode 10-11         system.out.println(this.val$y); // bytecode 14-21     } }