how to store multiple values in one key in hash table

[Raj kalaria]

Hi,

I am trying to parse and XML file and creating a hash table. I have never used Hash table before.

I want the Hash table to look like this
________________________________________
key value
doctype1 lib1
doctype1 lib2
doctype1 lib3

doctype2 lib1
doctype2 lib4

doctype3 lib2
---------------------------------------------

I tried the following code, but it overwrites my values
--------------------------------------------------------------------
Map map = new HashMap();
// Add some elements
map.put("1", "value1");
map.put("2", "value2");
map.put("3", "value3");
map.put("2", "value4");


// List the entries
for (Iterator it=map.keySet().iterator(); it.hasNext(); ) {
Object key = it.next();
System.out.println("the key is" + key.toString() );
Object value = map.get(key);
System.out.println("the value is" + value.toString() );
}
--------------------------------------------------------------------

Any suggestion would be really helpful to me

[Garrett Rowe]

You could use a HashMap that maps a particular key to a List

public class MapStringList
{
   private HashMap map;
 
   public MapStringList()
   {
      map = new HashMap();
   }
 
   public void add(String key, String value)
   {
      if (map.contains(key))
      {
         List values = (List)map.get(key);
         values.add(value);
      }
 
      else
      {
         List values = new ArrayList();
         values.add(value);
         map.put(key, values);
      }
   }
 
   public List getValues(String key)
   {
       return (List)map.get(key);
   }
{

[Jim Yingst]

For a ready-made solution, you might try using a MultiValueMap from Jakarta Commons Collections.

[Raj kalaria]

Thanks ,

will try and let you guys know