THE ONE WHO SOLVES THIS PROBLEM IS GREAT!

Question

I'm serious. I am so fed up I am with this problem. Ground rules: you must NOT just give me code. I need to be able to know why my problem is happening, and how to fix it myself. I'm a grad student and am bound by a code of conduct. I don't have any more time to spend investigating this. It could be something simple or complex...I am at a loss.
Here is the situation: I'm developing this console java application on my Windows PC. When I run it on my pc, it runs in under a minute. However, when I transfer my program to the servers at my school (sun unix workstations) it takes a ridiculous amount of time to run the same program. I am told that 80% of the students in my class have their programs running in less than 5 minutes. Almost all of them didn't have to do any kind of optimizations. They just wrote it, and it worked. My program is averaging 10-15 min, but my prof runs it locally at school, and says it takes 40 min!
The entire program is posted below. Please forgive me for not commenting so great. They were better at first, but when I started moving things around and changing everything, I threw comments out the window. Still, the existing comments should be helpful in understanding what I'm doing. NOTE: Below the code is the DTD that all the .xml files I'm parsing conforms to. Here are a few links to .xml files that represent part of the dataset. The actual dataset consists of 40 files totaling 30MB.
http://www.geocities.com/c_t_r_11/items-1.xml
http://www.geocities.com/c_t_r_11/items-10.xml
http://www.geocities.com/c_t_r_11/items-20.xml
the dtd is at:
http://www.geocities.com/c_t_r_11/itemsdtd.txt
And here is the code:
/* Instructions:
This program processes all files passed on the command line (to parse
an entire diectory, type "java MyParser myFiles/*.xml" at the shell).
At the point noted below, an individual XML file has been parsed into a
DOM Document node. You should fill in code to process the node. Java's
interface for the Document Object Model (DOM) is in package
org.w3c.dom. The documentation is available online at
http://java.sun.com/j2se/1.4/docs/api/index.html
A tutorial of DOM can be found at:
http://java.sun.com/webservices/docs/ea2/tutorial/doc/JAXPDOM.html#67581
Some auxiliary methods have been written for you. You may find them
useful.
Modified by:
Will
import java.io.*;
import java.text.*;
import java.util.*;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.FactoryConfigurationError;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.*;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.ErrorHandler;
class MyParser{
    static DocumentBuilder builder;
    static final String[] typeName = {
        "none",
        "Element",
        "Attr",
        "Text",
        "CDATA",
        "EntityRef",
        "Entity",
        "ProcInstr",
        "Comment",
        "Document",
        "DocType",
        "DocFragment",
        "Notation",
    static final String[] itemTags = {
        "Number_of_Bids",
        "Started",
        "Ends"
    static class MyErrorHandler implements ErrorHandler {
        public void warning(SAXParseException exception)
                throws SAXException {
            fatalError(exception);
        public void error(SAXParseException exception)
                throws SAXException {
            fatalError(exception);
        public void fatalError(SAXParseException exception)
                throws SAXException {
            exception.printStackTrace();
            System.out.println("There should be no errors " +
                    "in the supplied XML files.");
            System.exit(3);
    /* Non-recursive (NR) version of Node.getElementsByTagName(...) */
    static Element[] getElementsByTagNameNR(Element e, String tagName) {
        Vector elements = new Vector();
        Node child = e.getFirstChild();
        while (child != null) {
            if (child instanceof Element && child.getNodeName().equals(tagName))
                elements.add(child);
            child = child.getNextSibling();
        Element[] result = new Element[elements.size()];
        elements.copyInto(result);
        return result;
    /* Returns the first subelement of e matching the given tagName, or
    * null if one does not exist. */
    static Element getElementByTagNameNR(Element e, String tagName) {
        Node child = e.getFirstChild();
        while (child != null) {
            if (child instanceof Element && child.getNodeName().equals(tagName))
                return (Element) child;
            child = child.getNextSibling();
        return null;
    /* Returns the text associated with the given element (which must have
    * type #PCDATA) as child, or "" if it contains no text. */
    static String getElementText(Element e) {
        if (e.getChildNodes().getLength() == 1) {
            Text elementText = (Text) e.getFirstChild();
            return elementText.getNodeValue();
        else
            return "";
    /* Returns the text (#PCDATA) associated with the first subelement X
    * of e with the given tagName. If no such X exists or X contains no
    * text, "" is returned. */
    static String getElementTextByTagNameNR(Element e, String tagName) {
        Element elem = getElementByTagNameNR(e, tagName);
        if (elem != null)
            return getElementText(elem);
        else
            return "";
    /* Returns the amount (in XXXXX.xx format) denoted by a money-string
    * like $3,453.23. Returns the input if the input is an empty string. */
    static String strip(String money) {
        if (money.equals(""))
            return money;
        else {
            double am = 0.0;
            NumberFormat nf = NumberFormat.getCurrencyInstance(Locale.US);
            try { am = nf.parse(money).doubleValue(); }
            catch (ParseException e) {
                System.out.println("This method should work for all " +
                        "money values you find in our data.");
                System.exit(20);
            nf.setGroupingUsed(false);
            return nf.format(am).substring(1);
    /* Process one items-???.xml file. */
    static void processFile(File xmlFile) {
        Document doc = null;
        try {
            doc = builder.parse(xmlFile);
        catch (IOException e) {
            e.printStackTrace();
            System.exit(3);
        catch (SAXException e) {
            System.out.println("Parsing error on file " + xmlFile);
            System.out.println("  (not supposed to happen with supplied XML files)");
            e.printStackTrace();
            System.exit(3);
        /* At this point 'doc' contains a DOM representation of an 'Items' XML
        * file. Use doc.getDocumentElement() to get the root Element. */
        System.out.println("Successfully parsed - " + xmlFile);
        /*Open the output files for each relation****************************/
        PrintWriter itemsFile = null, usersFile = null,
                bidsFile = null, categoriesFile = null;
        /*Open files for writing each of the txt files******************/
        try{
            itemsFile = new PrintWriter(new BufferedOutputStream(new FileOutputStream("Items.dat", true)), true);
            usersFile = new PrintWriter(new BufferedOutputStream(new FileOutputStream("Users.dat", true)), true);
            bidsFile = new PrintWriter(new BufferedOutputStream(new FileOutputStream("Bids.dat", true)), true);
            categoriesFile = new PrintWriter(new BufferedOutputStream(new FileOutputStream("Categories.dat", true)), true);
        }catch(FileNotFoundException e){
            System.out.println("Error trying to open an output file: " + e.getMessage());
            System.exit(0);
        /*Parse content for each relation in turn********************/
        //Write to the Items.txt file
        NodeList itemNodes = doc.getDocumentElement().getElementsByTagName("Item");
        final String colSep = "|#|";
        String itemID = null;
        Element[] categories = null;
        NodeList bids = null;
        NodeList eBid = null;
        NodeList bidders = null;
        Element tempElement = null;
        Element itemElement = null;
        Element thisBid = null;
        String description = new String();
        for(int i=0; i<itemNodes.getLength(); i++){
            //Get the item Element for this iteration
            itemElement = (Element)itemNodes.item(i);
            /*Write out ItemID**************************************/
            itemID = itemElement.getAttribute("ItemID");
            itemsFile.print(itemID);
            itemsFile.print(colSep);
            /*Write out Name****************************************/
            itemsFile.print(getElementTextByTagNameNR(itemElement, "Name"));
            itemsFile.print(colSep);
            /*Write out the Currently element***********************/
            itemsFile.print(strip(getElementTextByTagNameNR(itemElement, "Currently")));
            itemsFile.print(colSep);
            /*Write out the Buy_Price element, if it exists*********/
            Element checkNode = null;
            if( (checkNode = getElementByTagNameNR(itemElement, "Buy_Price")) != null){
                itemsFile.print(strip(checkNode.getFirstChild().getNodeValue()));
            itemsFile.print(colSep);
            /*Add the First_Bid element*****************************/
            itemsFile.print(strip(getElementTextByTagNameNR(itemElement, "First_Bid")));
            itemsFile.print(colSep);
            /*Now iterate over the next three elements, adding them in turn*/
            for(int j=0; j<itemTags.length;j++){
                itemsFile.print(getElementTextByTagNameNR(itemElement, itemTags[j]));
                itemsFile.print(colSep);
            /*Add the SellerID**************************************/
            itemsFile.print(getElementByTagNameNR(itemElement, "Seller").getAttribute("UserID")
                    + colSep);
            /*Finally, add the description.  Truncate, if necessary*/
            description = getElementTextByTagNameNR(itemElement, "Description");
            itemsFile.print(description.substring(0, Math.min(4000, description.length())));
            itemsFile.print(colSep);
            itemsFile.println();
            /*Locate all of the Categories******************************/
            categories = getElementsByTagNameNR(itemElement, "Category");
            /*For every category in this item, write a ItemID-Category pair*/
            for(int j=0; j<categories.length; j++){
                categoriesFile.print(itemID + colSep);
                categoriesFile.print(categories[j].getFirstChild().getNodeValue());
                categoriesFile.println(colSep);
            if( (bids = itemElement.getElementsByTagName("Bid")) != null){
                /*Go through the bids, writing the info***********/
                for(int j=0; j<bids.getLength(); j++){
                    thisBid = (Element)bids.item(j);
                    bidsFile.print(getElementByTagNameNR(thisBid, "Bidder").getAttribute("UserID"));
                    bidsFile.print(colSep);
                    bidsFile.print(itemID);
                    bidsFile.print(colSep);
                    bidsFile.print(getElementTextByTagNameNR(thisBid, "Time"));
                    bidsFile.print(colSep);
                    bidsFile.print(strip(getElementTextByTagNameNR(thisBid, "Amount")));
                    bidsFile.println(colSep);
            /*write out userid and rating from any and all bidder nodes*/
            if( (bidders = itemElement.getElementsByTagName("Bidder")) != null){
                for(int j=0; j<bidders.getLength(); j++){
                    usersFile.print(bidders.item(j).getAttributes().getNamedItem("UserID").getNodeValue());
                    usersFile.print(colSep);
                    usersFile.print(bidders.item(j).getAttributes().getNamedItem("Rating").getNodeValue());
                    usersFile.print(colSep);
                    //If there's a location node, write it
                    if( getElementByTagNameNR((Element)bidders.item(j), "Location") != null){
                        usersFile.print(getElementTextByTagNameNR((Element)bidders.item(j), "Location"));
                    usersFile.print(colSep);
                    //If there's a country node, write it
                    if( getElementByTagNameNR((Element)bidders.item(j), "Country") != null){
                        usersFile.print(getElementTextByTagNameNR((Element)bidders.item(j), "Country"));
                    usersFile.println(colSep);
            /*Now write out the Seller information*******************/
            usersFile.print(getElementByTagNameNR(itemElement, "Seller").getAttribute("UserID"));
            usersFile.print(colSep);
            usersFile.print(getElementByTagNameNR(itemElement, "Seller").getAttribute("Rating"));
            usersFile.print(colSep);
            usersFile.print(getElementTextByTagNameNR(itemElement, "Location"));
            usersFile.print(colSep);
            usersFile.print(getElementTextByTagNameNR(itemElement, "Country"));
            usersFile.println(colSep);
        itemsFile.close();
        usersFile.close();
        bidsFile.close();
        categoriesFile.close();
    public static void main (String[] args) {
        if (args.length == 0) {
            System.out.println("Usage: java MyParser [file] [file] ...");
            System.exit(1);
/* Initialize parser. */
        try {
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            factory.setValidating(true);
            factory.setIgnoringElementContentWhitespace(true);
            builder = factory.newDocumentBuilder();
            builder.setErrorHandler(new MyErrorHandler());
        catch (FactoryConfigurationError e) {
            System.out.println("unable to get a document builder factory");
            System.exit(2);
        catch (ParserConfigurationException e) {
            System.out.println("parser was unable to be configured");
            System.exit(2);
/* Process all files listed on command line. */
        for (int i = 0; i < args.length; i++) {
            File currentFile = new File(args);
processFile(currentFile);
REMEMBER: Please do not just post the correct code. This will violate my code of conduct. I need tutoring--consultation.

Answer 1

If I was trying to get someone else to do my work,
I wouldn't be posting this saying what I have said
would I? I'm not unwilling to do the work myself.From what was stated in your OP, it seemed that you
were.I'm sorry if it seemed that way. I don't want something for nothing. I've spent MANY hours, which I don't have, trying to work this out. I have hit a point where I don't think my expertise is going to solve the problem. That's why I've turned to some experts who might say something along the lines of, "Hey, I know what that is...you're compiling against... and on the Unix box, it's compiling against..." I was NOT looking for something like, "See the code below that fixes your problem."
The only problem is that I don't have direct access
to the sun unix machines I'm running the app on,
so I can't run a profiler on it. Ah, okay. So the only knowledge you have of how it
performs on those machines is from your instructor
running it and then telling you how long it took?No. I can SSH into the servers and run the program from a command line. But I wouldn't be able to install any profiler programs.
You could ask your prof to run it with -Xprof or
-Xhprof or whatever. Or you could put in a bunch of
timing statements to get a rough idea of which parts
are making it take that extra 39 minute or whatever.is -Xprof a java command line option? If so, I will look into doing that. Maybe it's available on the machines at school. Thanks for that input.