code: public String[] loadAllRealNames ()
          throws PersistenceException
      {
          final ArrayList<String> names = new ArrayList<String>();
  
          // do the query
          execute(new Operation<Object>() {
              public Object invoke (Connection conn, DatabaseLiaison liaison)
                  throws PersistenceException, SQLException
              {
                  Statement stmt = conn.createStatement();
                  try {
                      String query = "select realname from users";
                      ResultSet rs = stmt.executeQuery(query);
                      while (rs.next()) {
                          names.add(rs.getString(1));
                      }
  
                      // nothing to return
                      return null;
  
                  } finally {
                      JDBCUtil.close(stmt);
                  }
              }
          });
  
          // finally construct our result
          return names.toArray(new String[names.size()]);
      }
docs: Returns an array with the real names of every user in the system.