This is a quick but v.important question.

Question

hi,
i have a thread thats part of a class that implements runnable (class b)
in it's run method it executes code that retrieves values in a database and stores it in a string array.
i need to pass this array to the caller class a.
how can this be done???
i know of using a set method to set the array in class b, but how could it be returned to class a, as i would have to pass a parameter to it, as this would be how it is set in class b.
this is very urgent, please help

Answer 1

public class PrimaryKeysFinder implements Runnable
    Vector cache;
    Connection dbconn;
    Statement stmt;
    String query = "select table_name, constraint_name from user_constraints  where constraint_type = 'P'";
     public PrimaryKeysFinder(Connection dbconn)
          this.dbconn = dbconn;
          Thread runner = new Thread(this);
          runner.start();
     public void retrievePrimaryKeyInfo()
                         cache = new Vector();
      try{
               stmt = dbconn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
               ResultSet rs = stmt.executeQuery(query);
               int columnCount = 2;
             int count = 0;
               while(rs.next())
                    String[] records = new String[columnCount];
                    for(int i = 1; i <= columnCount; i++)
                         records[i] = rs.getString(i);
                        cache.addElement(records);
           catch(Exception e)
                JOptionPane.showMessageDialog(null, "Error retrieving primary key info");
                 cache = new Vector();
     public void run()
          retrievePrimaryKeyInfo();
     public Vector getPrimaryKeyVector()
          return cache;
}but since cache is a global variable whatever i do to it in the method retrieveprimarykeyinfo wont matter as when getPrimaryKeyVector is invoked it returns the inital value of vector as null, not as what it's assigned in the method retrieveprimarykeyinfo.
thanks for the prompt reply