java - Automatically adding every Class object constructed into an ArrayList -

i'm still new in learning java , i'm in need of way put every object constructed class arraylist can access later.

here item class:

import java.util.arraylist; import java.util.*; public class item {     private string name;     private int quantity;     private arraylist<item> allitems = new arraylist<item>(); //the arraylist i'm trying fill every item object      /**      * constructs item of given name , quantity      * @param name item name      * @param quantity how of item player has      */     public item(string name, int quantity)     {         this.name = name;         this.quantity = quantity;     }      /**      * @return item name      */     public string getitemname()     {         return name;     }      /**      * @return quantity of item      */     public int getquantity()     {         return quantity;     }      /**      * @return list of items have quantity > 0      */     public arraylist<item> getinventory()     {         arraylist<item> inventory = new arraylist<item>();         for(item : allitems)         {             if(i.getquantity() > 0)                 inventory.add(i);         }         return inventory;     } } 

how can add item object allitems every time 1 constructed?

first, arraylis must static shared between instances. otherwise, have different variable per instance.

more info on instance/class members here.

private string name; private int quantity; private static arraylist<item> allitems = new arraylist<item>(); 

then, can add created instance in constructor, refering 'this'.

about 'this' keyword.

public item(string name, int quantity) {     this.name = name;     this.quantity = quantity;     allitems.add(this); }