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How can I retrieve data from a collection which is within a map?

Posted on 2004-10-12
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Last Modified: 2010-03-31
This function makes a call to listCustomerbyRef which then returns a map which includes 1) param   2) collection of customer details. i need to access these customer details from the collection and have the correct commands (commented out below at bottom of code) - but i cant retrieve these values

public void testListCustomersByRef() {
            
try{
                  TestableCustomerManager cm = new TestableCustomerManager();
                  Collection cusRef = new ArrayList();
                  Map result;
                  cusRef.add("0000564");
                  
                  result = cm.listCustomersByRef(cusRef,1);

                         //code missing to go here

                  
                  /*      cust.setRef((String) result.get("ref"));
                      cust.setName((String) result.get("name"));
                      cust.setRulesRow((Long) result.get("rules_row"));
                      cust.setLftCode((String) result.get("lftCode"));
                      cust.setLunCode((String) result.get("lunCode"));
                        System.out.println(cust.getName());
               
               
               
                CustContact custContact = new CustContact();
                custContact.setTitle((String) result.get("title"));
                custContact.setForename((String) result.get("forename"));
                custContact.setSurname((String) result.get("surname"));
                custContact.setTelNo((String) result.get("telNo"));
                custContact.setFaxNumber((String) result.get("faxNumber"));
                  System.out.println(custContact.getForename());
               
               
               
                Address address = new Address();
                address.setAddLine1((String) result.get("addLine1"));
                address.setAddLine2((String) result.get("addLine2"));
                address.setAddLine3((String) result.get("addLine3"));
                address.setAddLine4((String) result.get("addLine4"));
                address.setAddLine5((String) result.get("addLine5"));
                address.setPostTown((String) result.get("postTown"));
                address.setPostcode((String) result.get("postcode"));
                address.setCountry((String) result.get("country"));
               
                custContact.setAddress(address);
                //cust.setCustContacts((Set)custContact);
                  
                  System.out.println(cust.getName());
                  System.out.println("Tested listCustomersByRef method");*/
            }
            catch(ReadException e){
                  System.out.println(e.getMessage());
            }
            catch(Exception e){
                  System.out.println(e.getMessage());
            }
      }
0
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Question by:kullyN
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11 Comments
 
LVL 37

Accepted Solution

by:
zzynx earned 250 total points
ID: 12286736
>>... returns a map which includes 1) param   2) collection of customer details
What type of collection is that collection? List, Map, Set,...?

First you have to know which is the key (e.g. "coll")

List theCollection = (List) result.get("coll");
theCollection.get(0) gets the first element in that collection
0
 

Author Comment

by:kullyN
ID: 12286809
This is the code from the class which returns the map:


Collection coll = getCollectionFromSql(sQuery, params, true, pageno, true, true);
            HashMap result = new HashMap(2);
            result.put(CommonConstants.PARAM_RESULTS, coll);
0
 
LVL 37

Expert Comment

by:zzynx
ID: 12286939
Well, then this is how you retrieve that collection:

Collection coll = (Collection) result.get(CommonConstants.PARAM_RESULTS);
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LVL 37

Expert Comment

by:zzynx
ID: 12286960
And afterwards:

Iterator it = coll.iterator();
while (it.hasNext()) {
   ItemType item = (ItemType) it.next();  // ItemType being the type of the items in the collection
}
0
 
LVL 37

Expert Comment

by:zzynx
ID: 12286994
But Collection is just an interface
These are the classes that implement that interface:
AbstractCollection, AbstractList, AbstractSet, ArrayList, BeanContextServicesSupport, BeanContextSupport, HashSet, LinkedHashSet, LinkedList, TreeSet, Vector

It would be handy if you knew which one it was...
0
 

Author Comment

by:kullyN
ID: 12287480
none of these have worked, sorry
0
 
LVL 37

Expert Comment

by:zzynx
ID: 12287547
>> none of these have worked
What do you get?

Does

    result.containsKey(CommonConstants.PARAM_RESULTS)

return true?

If not, the collection simply isn't available in the map.
0
 

Author Comment

by:kullyN
ID: 12288972
i get null print statements

TestableCustomerManager cm = new TestableCustomerManager();
                  Collection cusRef = new ArrayList();
                  Map result;
                  
                  cusRef.add("0000564");
                  
                  result = cm.listCustomersByRef(cusRef,1);
                  Collection customers = (Collection)result.get(CommonConstants.PARAM_RESULTS);
                  
                  Iterator it = customers.iterator();
                  while (it.hasNext()) {
                     String item = (String) it.next();  // ItemType being the type of the items in the collection
                     System.out.println(item);
                  }
                  
0
 
LVL 37

Expert Comment

by:zzynx
ID: 12290802
What can I say?
If null's are coming out, that means that null's were added.
Time to critically investigate the working of

          result = cm.listCustomersByRef(cusRef,1);
0

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