asked on

Java code to read XML document

I am tyring to update the readProducts method so that is reads from the products.xml file but it wont compile.

these are the errors:
C:\Documents and Settings\ethatc001\My Documents\Murach\Java6\Exercises\java1.6\ch20\XMLTester\XMLTesterApp.java:49: cannot find symbol
symbol : method hasnext()
location: interface javax.xml.stream.XMLStreamReader
while (reader.hasnext())
^
C:\Documents and Settings\ethatc001\My Documents\Murach\Java6\Exercises\java1.6\ch20\XMLTester\XMLTesterApp.java:52: cannot find symbol
symbol : variable eventtype
location: class XMLTesterApp
                  switch (eventtype)
                   ^
C:\Documents and Settings\ethatc001\My Documents\Murach\Java6\Exercises\java1.6\ch20\XMLTester\XMLTesterApp.java:60: cannot find symbol
symbol : method setcode(java.lang.String)
location: class Product
                              p.setcode(code);
                               ^
3 errors

Here is the code:
import java.util.ArrayList;
import java.io.*;
import javax.xml.stream.*; // StAX API

public class XMLTesterApp
{
private static String productsFilename = "products.xml";

public static void main(String[] args)
{
System.out.println("Products list:");
ArrayList<Product> products = readProducts();
printProducts(products);

/*
Product p1 = new Product("test", "XML Tester", 77.77);
products.add(p1);
writeProducts(products);
System.out.println("XML Tester has been added to the XML document.\n");
*/

System.out.println("Products list:");
products = readProducts();
printProducts(products);

/*
products.remove(2);
writeProducts(products);
System.out.println("XML Tester has been deleted from the XML document.\n");
*/

System.out.println("Products list:");
products = readProducts();
printProducts(products);

}

private static ArrayList<Product> readProducts()
{
ArrayList<Product> products = new ArrayList<Product>();
Product p = null;

// add code that reads the XML document from the products.xml file
            XMLInputFactory inputFactory = XMLInputFactory.newInstance();
FileReader fileReader = new FileReader("products.xml");
XMLStreamReader reader = inputFactory.createXMLStreamReader(fileReader);

while (reader.hasnext())
{
                  int eventType = reader.getEventType();
                  switch (eventtype)
                  {
                        case XMLStreamConstants.START_ELEMENT:
                        String elementName = reader.getLocalName();
                        if (elementName.equals ("Product"))
                        {
                              p = new Product();
                              String code = reader.getAttributeValue(0);
                              p.setcode(code);
                        }
                        if (elementName.equals("Description"))
                        {
                              String description = reader.getElementText();
                              p.setDescription(description);
                        }
                        if (elementName.equals("Price"))
                        {
                              String priceString = reader.getElementText();
                              double price = Double.parseDouble(priceString);
                              p.setPrice(price);
                        }
                        break;
                        case XMLStreamConstants.END_ELEMENT:
                        elementName = reader.getLocalName();
                        if (elementName.equals("Product"))
                        {
                              products.add(p);
                        }
                        break;
                        default:
                        break;
                  }
                  reader.next();
            }
       return products;
}

private static void writeProducts(ArrayList<Product> products)
{
// add code that writes the XML document to the products.xml file
}

private static void printProducts(ArrayList<Product> products)
{
for (Product p : products)
{
printProduct(p);
}
System.out.println();
}

private static void printProduct(Product p)
{
String productString =
StringUtils.padWithSpaces(p.getCode(), 8) +
StringUtils.padWithSpaces(p.getDescription(), 44) +
p.getFormattedPrice();

System.out.println(productString);
}
}

for_yan

usually hasNext() upper case Next

for_yan

susually setCode() upper case Code

for_yan

and perhaps eventType - upper catse Type

for_yan

I don't have class Product to test

but hasnext() and evetType() I was right;

secode() is your own method from Product, so
you know better

for_yan

Post Product class if you want me to check it more

JChrison

switch (eventtype) Should be switch (eventType)

JChrison

and method hasnext() should be hasNext()

Mick Barry

try this:

public class XMLTesterApp
{
private static String productsFilename = "products.xml";

public static void main(String[] args)
{
System.out.println("Products list:");
ArrayList<Product> products = readProducts();
printProducts(products);

/*
Product p1 = new Product("test", "XML Tester", 77.77);
products.add(p1);
writeProducts(products);
System.out.println("XML Tester has been added to the XML document.\n");
*/

System.out.println("Products list:");
products = readProducts();
printProducts(products);

/*
products.remove(2);
writeProducts(products);
System.out.println("XML Tester has been deleted from the XML document.\n");
*/

System.out.println("Products list:");
products = readProducts();
printProducts(products);

}

private static ArrayList<Product> readProducts()
{
ArrayList<Product> products = new ArrayList<Product>();
Product p = null;

// add code that reads the XML document from the products.xml file
XMLInputFactory inputFactory = XMLInputFactory.newInstance();
FileReader fileReader = new FileReader("products.xml");
XMLStreamReader reader = inputFactory.createXMLStreamReader(fileReader);

while (reader.hasNext())
{
int eventType = reader.getEventType();
switch (eventType)
{
case XMLStreamConstants.START_ELEMENT:
String elementName = reader.getLocalName();
if (elementName.equals ("Product"))
{
p = new Product();
String code = reader.getAttributeValue(0);
p.setCode(code);
}
if (elementName.equals("Description"))
{
String description = reader.getElementText();
p.setDescription(description);
}
if (elementName.equals("Price"))
{
String priceString = reader.getElementText();
double price = Double.parseDouble(priceString);
p.setPrice(price);
}
break;
case XMLStreamConstants.END_ELEMENT:
elementName = reader.getLocalName();
if (elementName.equals("Product"))
{
products.add(p);
}
break;
default:
break;
}
reader.next();
}
return products;
}

private static void writeProducts(ArrayList<Product> products)
{
// add code that writes the XML document to the products.xml file
}

private static void printProducts(ArrayList<Product> products)
{
for (Product p : products)
{
printProduct(p);
}
System.out.println();
}

private static void printProduct(Product p)
{
String productString =
StringUtils.padWithSpaces(p.getCode(), 8) +
StringUtils.padWithSpaces(p.getDescription(), 44) +
p.getFormattedPrice();

System.out.println(productString);
}
}

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for_yan

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for_yan

This is similar to above, but padWithSpaces() replaced by rightPad() method
and Product stub is attached below

import org.apache.commons.lang.StringUtils;

import java.util.ArrayList;
import java.io.*;
import javax.xml.stream.*;  // StAX API

public class XMLTesterApp
{
    private static String productsFilename = "products.xml";

    public static void main(String[] args)
    {
        System.out.println("Products list:");
        ArrayList<Product> products = readProducts();
        printProducts(products);

/*
        Product p1 = new Product("test", "XML Tester", 77.77);
        products.add(p1);
        writeProducts(products);
        System.out.println("XML Tester has been added to the XML document.\n");
*/

        System.out.println("Products list:");
        products = readProducts();
        printProducts(products);

/*
        products.remove(2);
        writeProducts(products);
        System.out.println("XML Tester has been deleted from the XML document.\n");
*/

        System.out.println("Products list:");
        products = readProducts();
        printProducts(products);

    }

    private static ArrayList<Product> readProducts()
    {
        ArrayList<Product> products = new ArrayList<Product>();
        Product p = null;

        try {

        // add code that reads the XML document from the products.xml file
            XMLInputFactory inputFactory = XMLInputFactory.newInstance();
        FileReader fileReader = new FileReader("products.xml");
        XMLStreamReader reader = inputFactory.createXMLStreamReader(fileReader);


        while (reader.hasNext())
        {
                  int eventType = reader.getEventType();
                  switch (eventType)
                  {
                        case XMLStreamConstants.START_ELEMENT:
                        String elementName = reader.getLocalName();
                        if (elementName.equals ("Product"))
                        {
                              p = new Product();
                              String code = reader.getAttributeValue(0);
                              p.setCode(code);
                        }
                        if (elementName.equals("Description"))
                        {
                              String description = reader.getElementText();
                              p.setDescription(description);
                        }
                        if (elementName.equals("Price"))
                        {
                              String priceString = reader.getElementText();
                              double price = Double.parseDouble(priceString);
                              p.setPrice(price);
                        }
                        break;
                        case XMLStreamConstants.END_ELEMENT:
                        elementName = reader.getLocalName();
                        if (elementName.equals("Product"))
                        {
                              products.add(p);
                        }
                        break;
                        default:
                        break;
                  }
                  reader.next();
            }
         
    }  catch(Exception ex){
            System.out.println("error " + ex.toString());
            ex.printStackTrace();
        }
         return products;
    }

    private static void writeProducts(ArrayList<Product> products)
    {
        // add code that writes the XML document to the products.xml file
    }

    private static void printProducts(ArrayList<Product> products)
    {
        for (Product p : products)
        {
            printProduct(p);
        }
        System.out.println();
    }

    private static void printProduct(Product p)
    {
        String productString =
            StringUtils.rightPad(p.getCode(), 8) +
            StringUtils.rightPad(p.getDescription(), 44) +
            p.getFormattedPrice();

        System.out.println(productString);
    }
}

class Product{
    public void setCode(String s){

    }
      public void setDescription(String s){

    }
        public void setPrice(double d){

    }

      public String getCode(){
          return null;

    }
       public String getDescription(){
                return null;
    }

    public double getFormattedPrice(){
          return 0.0;
    }
}

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edthatcher

ASKER

thank you