getting Employee Object out of HashMap

[fischen]

What is I want to do is retrieve a value out of a hashmap, the value is an Employee Object stored in an ArrayList.

? How do I accomplish this?

=========== here's my psuedocode ========

read employee.file into an strLineArray
split the strLineArray into ID, FirstName, LastName, and Phone fields;

Employee employee = new Employee(ID, FirstName, LastName, Phone);

ArrayList directory = new ArrayList();

directory.add(employee);

lastNameMap = new HashMap();

lastNameMap.put(new String(lastName), directory);
===================================

Question: how do I get an employee out the lastNameMap, given a lastName information?

Can someone also verify that I .put the directory (ArrayList) in the lastNameMap?

Thanks a bunch,
Fischen

[evlich]

I think you want to do .put(lastName, employee). Then you should be able to do .get(lastName) and it will give you employee back.

Hope this helps.

[fischen]

For a different method, for add and retrieving ids from an idMap; this works fine. What about people with the same Last Name. For example if you have 14 "smiths" I would only receive the last "smiths" in the hastable.

Fischen

[evlich]

Ok, in this case, you will want to preserve the information. You can do this very easily using a modified put.

void putSet(String lastName, Employee emp, HashMap map) {
  Set set = map.get(lastName);
  if( set == null ) {
    set = new TreeSet();
    set.add(emp);
    map.put(set);
  } else {
    set.add(emp);
  }
}

I personally think that sets are a little more logical here than array lists because you can get an implicit ordering and you don't want a person to occur multiple times in your table.

Hope this helps.

[fischen]

I'll give your method a try.

Fischen.

[fischen]

I wrote a separate method to add objects to a hashtable. In this situation, I need to be able to store multiple last name.

-----method accepts two arguements(String lastName, Employee aEmployee)
if (lastNameMap.containsKey(lastname) {
ArrayList uniqueLastName = new ArrayList();
uniqueLastName.add(aEmployee);
lastNameMap.put(lastName, uniqueLastName )
}
else {
ArrayList sameLastName = new ArrayList();
sameLastName = (ArrayList)lastNameMap.get(lastName);
sameLastName.add(aEmployee);
lastNameMap.put(lastName, sameLastName)
}

--------------------
The above method allows you to add multiple Employees of 'Smith' with a key of 'Smith'

Without doing this (unless you use a database) you will not be able to add say, 'Jackie Smith' and 'John Smith' because the last add to the lastName map will overwite the previous. Because the key in a hashtable must be unit. So a lastNameMap can only contain one 'Smith' key.

I hope this helps anyone that reads this posting.

Fishen

[vcinfy]

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Regards
Vivek

[vcinfy]

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