public void setUsername(String uname) {

       if( getUsername() != null) {
          if(!getUsername().equals(uname)) {
             super.setUsername(uname);
             conn = null;
             ps = null;
             rs = null;
          }
       }
       else{
          super.setUsername(uname);
       }
    }
Sets the username property for this <code>JdbcRowSet</code> object
to the given user name. Because it
is not serialized, the username property is set at run time before
calling the method <code>execute</code>. In addition,
if the <code>username</code> property is already set with a
non-null value and that value is different from the <code>String</code>
object to be set,
this method sets this <code>JdbcRowSet</code> object's private fields
<code>ps</code>, <code>rs</code>, and <code>conn</code> to <code>null</code>.
(The field <code>ps</code> is its <code>PreparedStatement</code> object,
<code>rs</code> is its <code>ResultSet</code> object, and
<code>conn</code> is its <code>Connection</code> object.)
Setting these fields to <code>null</code> ensures that only current
values will be used.

@param uname the <code>String</code> object containing the user name that
    is supplied to the data source to create a connection. It may be null.
@see #getUsername
src/main/java/org/replicadb/rowset/sun/rowset/JdbcRowSetImpl.java