DB4o HashMap toString()

As a learning tool for DB4o and Java I have started to create a Telephone Directory. To do this I create an instance of a TelephoneDirectory which contains a year and a HashMap of entries.

Code:

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public class TelephoneDirectory {
  private int year;
  private HashMap<String, String> hashmap;

  public TelephoneDirectory(int year) {
    this.year = year;
    this.hashmap = new HashMap<String, String>();
  }

  public int getYear() {
    return year;
  }

  public HashMap getHashmap() {
    return hashmap;
  }

  public void addEntry(String name, String number) {
    hashmap.put(number, name);
  }
}

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So I add a few entries with addEntry. What I would like to do is search through the telephone directory for a specific name. For this I use QueryByExample (QBE), like so:

Code:

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public static void lookupName(String name, int year, ObjectContainer db) {

  TelephoneDirectory proto = new TelephoneDirectory(year);
  proto.addEntry(name, null);

  ObjectSet result=db.queryByExample(proto);

  System.out.println("Size:" + result.size());
  while(result.hasNext()) {
    System.out.println(result.next());
  }
}

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The issue that I am having with this is that if a result is found in the hashmap, then I need the key/value pair to be printed. So far the output is:

Quote:

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Size:1 telephonedirectory.TelephoneDirectory@da4b71

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This is obviously because there is no toString() method. But what do I put in the toString() method as only a subset of hashmap values will be present in the result.

Example

Code:

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TelephoneDirectory dir = new TelephoneDirectory(2011);
dir.addEntry("12345", "Adam");
dir.addEntry("67890", "Bob");
dir.addEntry("24680", "Carl");

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And I then query:

Code:

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lookupName("Bob", 2011, db);

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Expected Result:

Quote:

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2011 - 67890: Bob

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I am sure that it is something simple that I am overlooking.

Thanks in advance.

An person class would be very helpful, however; what happens if you get the key I'm the print line?

Quote:

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Originally Posted by sunde887

An person class would be very helpful, however; what happens if you get the key I'm the print line?

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I'm not quite sure I understand what you mean with the last bit?

I'm not really familiar with databases, however; it seems that you are printing a telephone directory, if you can get access to the map you can find the name of the person in the map, correct?


I apologize if I am being a bit unclear. You gave yourself the ability to access the year and map in the directory, your result.next is returning a telephone directory so you can access the information.

Well the QBE returns an ObjectSet which contains the results and hence I shouldnt need to find they key/value pairs. They should already be there, its just a case of displaying them...