I have a book.xml file, my xml file:-
======================================
<?xml version="1.0" ?>
<books>
<book category="reference">
<author>Kevin William</author>
<title>Cooking Lean</title>
<price>10.99</price>
</book>
<book category="fiction">
<author>Oprah</author>
<title>Star Track II</title>
<price>12.99</price>
</book>
<book category="fiction">
<author>Andy Koh</author>
<title>Basketball Freak</title>
<price>54.99</price>
</book>
<book category="reference">
<author>Irene Kim</author>
<title>Living Lean</title>
<price>50.99</price>
</book>
</books>
=============================
I want to find the average price of the books according to their category. For example, category "fiction" ... the average price will be ($12.99 + $54.99 ) / 2 ... how can I do that? I am using SAX with Java. My code as follow, but I found that my total price dind't accumulate ... :( so the average price always 0.0 ...
==============================
import org.xml.sax.Attributes;
final class Sink extends org.xml.sax.helpers.DefaultHandler implements org.xml.sax.ContentHandler
{
private int count = 0;
private int t = 0;
private int book = 0;
private int fiction = 0;
private int reference = 0;
public double AF = 0.0;
public double RF = 0.0;
public double averageF = 0.0;
public double averageR = 0.0;
public boolean isFiction = false;
public boolean isReference = false;
public StringBuffer content = new StringBuffer();
final private void print ( final String context, final String text )
{
System.out.println( context + ": " + text + "." );
t = count + 1;
count = t;
if (t % 4 == 0)
{
System.out.println("");
}
}
final private String firstPrint (final String text)
{
System.out.print(text);
return text;
}
final public void startElement ( final String namespace, final String localname, final String type, final org.xml.sax.Attributes attributes ) throws org.xml.sax.SAXException
{
if (type.equals("book"))
{
book++;
String category = attributes.getValue("category");
isFiction = category.equals("fiction");
isReference = category.equals("reference");
if (isFiction) {
fiction++;
print("Category", category);
}
if (isReference) {
reference++;
print("Category", category);
}
content.setLength(0);
}
if (type == "author")
{
firstPrint ("Author");
}
if (type == "title")
{
firstPrint ("Title");
}
if (type == "price")
{
firstPrint ("Price");
}
}
final public void endElement (final String name) throws org.xml.sax.SAXException
{
if ((name.equals("price")) && isFiction)
{
double price = new Double(content.toString()).doubleValue();
averageF = averageF + price;
// content.setLength(0);
}
if ((name.equals("price")) && isReference)
{
final double price2 = new Double(content.toString()).doubleValue();
averageR = averageR + price2;
//content.setLength(0);
}
}
final public void endDocument() throws org.xml.sax.SAXException
{
AF = averageF / fiction;
RF = averageR / reference;
totalBooks(book, fiction, reference, AF, RF);
}
final public void characters ( final char[] ch, final int start, final int len )
{
content.append(ch, start, len);
final String text = new String( ch, start, len );
final String text1 = text.trim();
if( text1.length() > 0 ) {
print("", text1);
}
}
final private void totalBooks(final int num, final int fic, final int ref, final double aFic, final double aRef)
{
System.out.println("There are total " + num + " books in the XML file.");
System.out.println("There are " + fic + " FICTION books in the XML file. Average price is: $" + aFic);
System.out.println("There are " + ref + " REFERENCE books in the XML file. Average price is: $" + aRef);
}
}
how to add all <price> element value?
