Question

Please advise.. In the following code(Tested. Will work fine)

public class Exp_Test { 
     public static void main (String[] args) {
        ArrayList<Hashtable> objArrlistHshTbl = new ArrayList<Hashtable>();

        Hashtable objHashTable = new Hashtable();

        objHashTable.put("Key1", "Value1");
        objHashTable.put("Key2", "Value2");

        objArrlistHshTbl.add(objHashTable);

        objHashTable.clear();

        objHashTable.put("Key3", "Value3");
        objHashTable.put("Key4", "Value4");

        objArrlistHshTbl.add(objHashTable);
        System.out.println("Hi");//put a breakpoint here to check the values
    }
}

I am expecting to see an arraylist with to Hashtables saved as array elements, first one with keys ‘Key1’ and ‘Key2’, Second one with Keys ‘Key3’ and ‘Key4’. I get an array list with two hash tables, but values and keys inside hash table are coming as ‘Key3’ and ‘key4’ for both tables. Could someone explain. If it is a reference problem, how do I get two hash tables in to different array elements withouot creating multiple hash tables(I have to run the code inside a for loop to add multiple hash tables.Creating separate hash tables every time does not sound good)

Answer 1

Solved

public static void main (String[] args) {
    ArrayList<Hashtable> objArrlistHshTbl = new ArrayList<Hashtable>();
    for(int i= 1; i< 3; i++){
              if(i == 1){
              Hashtable objHashTable = new Hashtable();
    objHashTable.put("Key" + i, "Value1");
    objHashTable.put("Key" + i+1, "Value2");
              objArrlistHshTbl.add(objHashTable);
              }else{
                  Hashtable objHashTable = new Hashtable();
                  objHashTable.put("Key" + i, "Value3");
        objHashTable.put("Key" + i+1, "Value4");
                  objArrlistHshTbl.add(objHashTable);
              }

    }


    }
}