Hashtable in java is giving me the last stored value, but not the right value

Question

Sorry this is kinda long, but I needed to get the right scenario. This outputs all C's, why?? thanks in advance

import java.util.Hashtable;

public class Main {  
    public static ContainsTheHash containsthehash = new ContainsTheHash();  
    public static StoresValues storesvalues = new StoresValues();  
    public static GetsValuesAndPrints getsvaluesandprints = new GetsValuesAndPrints();  
    public static void main(String[] args) {}  

}

class ContainsTheHash {

    Hashtable script_code = new Hashtable();  
    public Contains_The_Hash() {};  
    public void put(long key, Script_Hash_Type sht){script_code.put(key, sht);}  
    public ScriptHashType get(long key){return (Script_Hash_Type)script_code.get(key);}  

}

class ScriptHashType {

     String string;  
     public ScriptHashType(){}  
     public String getstring () {return string;}  
     public void setstring(String str){string = str;}  

}



 class StoresValues {

     public StoresValues(){
         put();
     }
     public void put(){


          ScriptHashType sht = new ScriptHashType();  
          sht.setstring("A");  
          Main.contains_the_hash.put(1,sht);  
          sht.setstring("B");  
          Main.contains_the_hash.put(2,sht);  
          sht.setstring("C");  
          Main.contains_the_hash.put(3,sht);  
     }  

}

class GetsValuesAndPrints {

    public GetsValuesAndPrints(){  

           //should print "A\n B\n  C\n"  
           long temp = 1;  
           System.out.println(get(temp));  
           temp = 2;  
           System.out.println(get(temp));  
           temp = 3;  
           System.out.println(get(temp));  
    };


    public String get(long key){  

        return new String(((Script_Hash_Type)Main.contains_the_hash.get(key)).getstring());  

   }
}

Answer 1

Change :

ScriptHashType sht = new ScriptHashType();
sht.setstring("A");
Main.contains_the_hash.put(1,sht);
sht.setstring("B");
Main.contains_the_hash.put(2,sht);
sht.setstring("C");
Main.contains_the_hash.put(3,sht);

to

ScriptHashType sht = new ScriptHashType();
sht.setstring("A");
Main.contains_the_hash.put(1,sht);
sht = new ScriptHashType();
sht.setstring("B");
Main.contains_the_hash.put(2,sht);
sht = new ScriptHashType();
sht.setstring("C");
Main.contains_the_hash.put(3,sht);

In the first piece of code You're updating the same object each time

Answer 2

class StoresValues {

     public StoresValues() {
         put();
     };

     public void put() {
          ScriptHashType sht = new ScriptHashType();  
          sht.setstring("A");  
          Main.contains_the_hash.put(1,sht);  
          sht.setstring("B");  
          Main.contains_the_hash.put(2,sht);  
          sht.setstring("C");  
          Main.contains_the_hash.put(3,sht);  
     }

You build only one single object, sht, using the new operator. You add that object 3 times. The last setstring on that object sets the string to "C". As there is only 1 object sht that single object will have the value "C".

What you should have done is something like:

 public void put() {
  ScriptHashType sht = new ScriptHashType();  
  sht.setstring("A");  
  Main.contains_the_hash.put(1,sht);  
  sht = new ScriptHashType();  
  sht.setstring("B");  
  Main.contains_the_hash.put(2,sht);  
  sht = new ScriptHashType();  
  sht.setstring("C");  
  Main.contains_the_hash.put(3,sht);  
 }

Answer 3

You are only ever storing one instance of ScriptHashType into the Hashtable and then manipulating its value. To get the behavior you are expecting you would need to create three instances of ScriptHashType, one for each desired value.