Why not parsing using JDOM?

Question

Please see the xml file & my java code. The code seems ok..but not parsing right! Please advise, where the problem is?? Also, how do I extract the Supplier tag in this example file??? Any help is really appreciated!!!
<POOutbound_schema PurchaseOrder="P415704423" OrderDate="2003-06-05"><DocRouting/><Supplier Account="152625001" CompanyName="REP " Address1="ATTENTION SALES " Address2="XXXXXXXXXX " City="XXXXX " Address4=" " Address5=" " Address6=" " State="KA" CountryCode=" " ZipCode="67223 " Phone="833-555-5555" Fax="333-670-3324" OrderStatus="CLOSED AND PRINTED" Comments="DO NOT SHIP TEST PO " TransmissionDate="2003-06-05" TransmissionTime="17:14:54"/><Buyer CompanyName="XXXXXXXXX" Phone="222-577-3708" Fax=" " BuyerNumber="101000" BuyerName="1IM " Email="[email protected]"/><DeliveryAddress CompanyName=" ENSEN COMPANY " Address1="C/O SHIPPING " Address2="221900 SHI BLVD " City="SCHG " Address4=" " Address5=" " Address6="SCHAUMBURG " State="IL" ZipCode="65693 " Phone="800-444-4448" ShipDeptContactName="HHHHN "/><PaymentTerms DueDays="30" DiscountDays="10" DiscountPercent="0"/><DeliveryTerms PrePaid="Prepaid" Transport="TO BE DETERMINED " Fob="ORIGIN "/><OrderLine TransmissionID="-2147482947" ItemNo="506280 " BranchNumber="00423" Description="3-3/4 RD X 20' R/L " QuantityUnitOfMeasure="Pound" PriceUnitOfMeasure="Pound" UnitPrice1="1.0000" UnitPrice2="71.0000" ForeignCurrencyCode="USD" BaseCurrencyCode="USD" DueDate="2003-06-05" POLineNumber="1" Qty="1.0000" SizeDescription="140/41 HR ANN ASTM A322 " LineStatus="Open"><LineNotes OrderLineNote="440/414 HR BAR - LP ANLED - LATT REV ASTM A32, A304 "/><LineNotes OrderLineNote="- AIM .025 MAP AN S - CERT/R RD - 410/412H HABILITY "/><LineNotes OrderLineNote="REQD - STAMP HEAT NUMBER ONE END ON SIZES 2-1/2" AND OVER - "/><LineNotes OrderLineNote="GRAIN SIZE 5 OR FINER - REPORT NI,CU,V AND HARDNESS "/></OrderLine><OrderLine TransmissionID="-2147482946" ItemNo="502327 " BranchNumber="00423" Description="3/4 SQ X 12' R/L " QuantityUnitOfMeasure="Pound" PriceUnitOfMeasure="Pound" UnitPrice1="1.0000" UnitPrice2="1.0000" ForeignCurrencyCode="USD" BaseCurrencyCode="USD" DueDate="2003-06-05" POLineNumber="2" Qty="1.0000" SizeDescription="1018 CF ASTM A108 " LineStatus="Open"><LineNotes OrderLineNote="1018 CF BAR - LATEST REV: ASTM A108 - CERT T/R REQD "/><LineNotes OrderLineNote=" "/></OrderLine><OrderLine TransmissionID="-2147482945" ItemNo="507027 " BranchNumber="00423" Description="5-3/4 RD X 20' R/L " QuantityUnitOfMeasure="Pound" PriceUnitOfMeasure="Pound" UnitPrice1="1.0000" UnitPrice2="1.0000" ForeignCurrencyCode="USD" BaseCurrencyCode="USD" DueDate="2003-06-05" POLineNumber="3" Qty="1.0000" SizeDescription="86/80H HR ASTM A322 ASTM A304 " LineStatus="Open"><LineNotes OrderLineNote="8/86H HOT RO BA - LAST REVASTM A32AND ATM A304 - AIM "/><LineNotes OrderLineNote=".025 MAX P AND S - STAMUMBER ON ONE END SIZES 2-1/2" AND OVER "/><LineNotes OrderLineNote="GRA SIZE OR FINER - HARDEILITY TO BE REPORTED - CET /R REQD "/></OrderLine></POOutbound_schema>
import java.io.File;
import java.io.FilenameFilter;
import java.io.*;
import java.lang.*;
import org.jdom.*;
import org.jdom.input.*;
import org.jdom.output.*;
import java.util.*;
public class EmjPO
public static void main (String args[]) {
String[] outarray=new String[1000];
String pono=null;
int j=0;
try {
/* Build the document with SAX and Xerces, no validation */
SAXBuilder builder = new SAXBuilder();
/* Create the document */
Document doc = builder.build(new File("c:/emjdata/PO.xml"));
/* To get the DocType from in xml file. Reads the Doctype. */
DocType docType = doc.getDocType();
/* Get the root element. */
Element root = doc.getRootElement();
/* Get Children */     
List rtiloadoutbound = root.getChildren("POOutbound_schema");
Iterator i = rtiloadoutbound.iterator();
while (i.hasNext()) {
Element rti_load_outbound = (Element) i.next();
/* Parses each tag to output string */
String PurchaseOrder = rti_load_outbound.getAttributeValue("PurchaseOrder");
String OrderDate = rti_load_outbound.getAttributeValue("OrderDate");     
System.out.println(" Purchase Order : " + PurchaseOrder + " " + OrderDate);
} /* while ends here */
} /* try ends here */
catch (Exception ex) {
ex.printStackTrace();     
System.out.println("Exception Occured " + ex);

Answer 1

The stack trace should tell you the line number and the filename where the exception happened.
This is just a guess:
List rtiloadoutbound = root.getChildren("POOutbound_schema"); //this returns null because root iself the element 'POOutbound_schema'
Iterator i = rtiloadoutbound.iterator(); //calling .iterator() on a null gives the NullPointerExceptionso try
String PurchaseOrder = root.getAttributeValue("PurchaseOrder");
String OrderDate = root.getAttributeValue("OrderDate");