Now, I want to transfer my data in the network, my client maybe a Jsp/Servelt, or a Delphi client. So I should transfer my data in xml format.
   But, I don't know how to transfer a ResultSet into Xml Object that can be read by Delphi client? I think i should provide a string stream in xml format? but i don't know how to solve it? sigh, there are too many tech about xml for me to select...

Here's a simple hack for generating XML from a ResultSet. It came from the top of my head and I haven't tested it in anyway, but I think it should work (for the basic numeric, alphanumeric and time-related SQL types).

/**
 * Returns an XML representation of the given ResultSet.
 */
private String resultSetToXml(ResultSet rs)
{
    ResultSetMetaData rsmd = rs.getMetaData();
    int numberOfColumns = rsmd.getColumnCount();
    int row = 0;

    StringBuffer xml = new StringBuffer(1000);
    xml.append("<?xml version=\"1.0\"?>");
    xml.append("<resultset>");
    while (rs.next())
    {
        row++;
        xml.append("<row number=\"" + row + "\">");
        for (int i=0; i < numberOfColumns; i++)
        {
            Object obj = rs.getObject(i);
            xml.append("<column");
            xml.append(" name=\"" + rsmd.getColumnName(i) + "\"");
            xml.append(" type=\"" + obj.getClass().getName() + "\"");
            xml.append(" value=\"" + obj.toString() + "\"");
            xml.append("/>");
        }
        xml.append("</row>");
    }
    xml.append("</resultset>");

    return xml.toString();
}


...and the resulting XML should look like this:

<?xml version="1.0"?>
<resultset>
  <row number="1">
    <column name="id" type="java.lang.Integer" value="123"/>
    <column name="price" type="java.lang.Float" value="123.45"/>
    <column name="timestamp" type="java.sql.Timestamp" value="2002-01-23 12:34:56.0"/>
  </row>
  <row number="2">
    <column name="id" type="java.lang.Integer" value="456"/>
    <column name="price" type="java.lang.Float" value="543.21"/>
    <column name="timestamp" type="java.sql.Timestamp" value="2002-02-02 23:45:01.0"/>
  </row>
  ...
</resultset>

another way to could do it is to use webservices and have other clients call the webservice and get the results from the method , as the overall meaning of webservices is to provide operatiblity between different programming languages

What about SUN's WebRowSet?