Sample code to override the handlerAfterInsertRow method

public void handleAfterInsertRow(Connection con, HandlerContext context, BaseModel row) throws Exception {

    //cast it to RPCModelData - using this you can access to the data thats been inserted
     RPCModelData data = (RPCModelData) row;

   //use the HandlerContext object to get access to ScriptUtil
    ScriptUtil db = context.getScriptUtil();

    //Its a custom method that creates a XML file
    InputStream xmlStream = writeXMLFile(data);

    //generate a sequence id using the ScriptUtil utility methods
     double xmlId = db.getNextVal("T_APP_NOTE_XML_S");

    //Use the connection object to write data into a table
     insertXML(con, context, data, xmlStream, xmlId);

    //use the sendEmail method to sent an email
     String noteTitle = row.get("title");
     String subject = "New Note Created - " + noteTitle;
     db.sendEmail("[e-mail]", null, subject, "Email content", "N");
 }

Once you have the java class compiled and ready, enter the fully qualified class name in the "Object Handler Class" field on the data source header.