SAX căn bản - phân tích XML (dữ liệu thời tiết trực tuyến)

Ví dụ sử dụng SAX phân tích nội dung XML trực tuyến (thông tin dự báo thời tiết)
Nội dung XML

Nội dung hiện thị sau phân tích

Mã nguồn ví dụ
[sourcecode language="java"]
package codes;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
/**
* @author ntdan
*/
public class SAXParser_RSS extends DefaultHandler {
String urlPath = "http://api.openweathermap.org/data/2.5/forecast?q=can+tho,vn&mode=xml";
String strresult = "";
int count = 1;
boolean namefound = false;
boolean itemfound = false;

public String parse() {
try {
SAXParserFactory fac = SAXParserFactory.newInstance();
SAXParser sax = fac.newSAXParser();
// ket noi truc tiep
URL url = new URL(urlPath);
URLConnection conn = url.openConnection();
InputSource in = new InputSource(conn.getInputStream());
// phan tich tu luon truc tuyen
sax.parse(in, this);
return strresult;
} catch (ParserConfigurationException ex) {
Logger.getLogger(SAXParser_RSS.class.getName()).log(Level.SEVERE, null, ex);
} catch (SAXException ex) {
Logger.getLogger(SAXParser_RSS.class.getName()).log(Level.SEVERE, null, ex);
} catch (MalformedURLException ex) {
Logger.getLogger(SAXParser_RSS.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(SAXParser_RSS.class.getName()).log(Level.SEVERE, null, ex);
}
return strresult;
}

@Override
public void characters(char[] ch, int start, int length) throws SAXException {
super.characters(ch, start, length); //To change body of generated methods, choose Tools | Templates.

if (namefound) {
strresult += "<b>Location</b>: " + new String(ch, start, length) + "!<br/>";
namefound = false;
}
}

@Override
public void endElement(String uri, String localName, String qName) throws SAXException {
super.endElement(uri, localName, qName); //To change body of generated methods, choose Tools | Templates.

if (qName.equalsIgnoreCase("item")) {
strresult += "<br/>";
itemfound = false;
}
}

@Override
public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
super.startElement(uri, localName, qName, attributes); //To change body of generated methods, choose Tools | Templates.
if (qName.equalsIgnoreCase("name")) {
namefound = true;
}

if (qName.equalsIgnoreCase("item")) {
itemfound = true;
}

if (qName.equalsIgnoreCase("time")) {
strresult += count++ + ". <i>Time<i> <b>From</b>: " + attributes.getValue("from")
+ " <b>To</b>: " + attributes.getValue("to");
}

if (qName.equalsIgnoreCase("humidity")) {
strresult += " <i>Humidity</i>: " + attributes.getValue("value")
+ attributes.getValue("unit") + "<br/>";
}

if (qName.equalsIgnoreCase("temperature")) {
strresult += " <b>Temperature</b>: <b>from</b> "
+ attributes.getValue("min") + " <b>to</b> "
+ attributes.getValue("max") + "-"
+ attributes.getValue("unit");
}
}

@Override
public void endDocument() throws SAXException {
super.endDocument(); //To change body of generated methods, choose Tools | Templates.
strresult += "<br/>End parsing ...";
}

@Override
public void startDocument() throws SAXException {
super.startDocument(); //To change body of generated methods, choose Tools | Templates.
strresult += "Start parsing ... <br/>";
}
}
[/sourcecode]

goodluck!!!