CVS Update: xmlpull-api-v1/src/java/samples

aslom       02/08/23 14:45:25

  Modified:    src/java/samples BestDeal.java
  Added:       src/java/samples RSSReader.java rss.xml
  Log:
  sampel RSS reader that shows how to use XmlPullParser and XmlSerializer
  to filter and transform XML input
  (taken from XML.COM article that compared XmlPull API and .NET
  now finally we have xml serialzier to write output ...)
  
  Revision  Changes    Path
  1.4       +32 -32    xmlpull-api-v1/src/java/samples/BestDeal.java
  
  Index: BestDeal.java
  ===================================================================
  RCS file: /l/extreme/cvspub/xmlpull-api-v1/src/java/samples/BestDeal.java,v
  retrieving revision 1.3
  retrieving revision 1.4
  diff -u -b -t -w -r1.3 -r1.4
  
  
  
  1.1                  xmlpull-api-v1/src/java/samples/RSSReader.java
  
  Index: RSSReader.java
  ===================================================================
  // modified by Aleksander Slominski
  // based on http://www.xml.com/pub/a/2002/05/22/parsing.html?page=2
  
  import java.io.*;
  import java.net.*;
  import java.util.*;
  
  import org.xmlpull.v1.*;
  
  public class RSSReader {
  
      public static void main(String [] args)
      {
  
          // create an instance of RSSReader
          RSSReader rssreader = new RSSReader();
  
          try {
              XmlPullParserFactory factory = XmlPullParserFactory.newInstance();
              XmlPullParser parser = factory.newPullParser();
              String url = args[0];
              InputStreamReader stream = new InputStreamReader(
                  new URL(url).openStream());
              parser.setInput(stream);
              XmlSerializer writer = factory.newSerializer();
              writer.setOutput(new OutputStreamWriter(System.out));
              rssreader.convertRSSToHtml(parser, writer);
          } catch (Exception e) {
              e.printStackTrace(System.err);
          }
      }
  
      public void convertRSSToHtml(XmlPullParser parser, XmlSerializer writer)
          throws IOException, XmlPullParserException
      {
          // <!ELEMENT rss (channel)>
          if (parser.nextTag() == XmlPullParser.START_TAG
              && parser.getName().equals("rss"))
          {
              writer.startTag(null,"html");
              if (parser.nextTag() == XmlPullParser.START_TAG
                  && parser.getName().equals("channel"))
              {
                  convertChannelToHtml(parser, writer);
                  parser.require(XmlPullParser.END_TAG, null, "channel");
              } else {
                  new RuntimeException("expectd channel start tag not "+parser.getPositionDescription());
              }
              parser.nextTag();
              parser.require(XmlPullParser.END_TAG, null, "rss");
              writer.endTag(null, "html");
              writer.flush();
          } else {
              throw new RuntimeException("expectd an RSS document at" + parser.getPositionDescription());
          }
      }
  
      public void convertChannelToHtml(XmlPullParser parser, XmlSerializer writer)
          throws IOException, XmlPullParserException
      {
          // <!ELEMENT channel (title | description | link | language | item+ | rating? | image? | textinput? | copyright? | pubDate? | lastBuildDate? | docs? | managingEditor? | webMaster? | skipHours? | skipDays?)*>
          boolean seenBody = false; //assumption that title is before items ...
          while (parser.nextTag() != XmlPullParser.END_TAG) { // this guranteed by well formednes of XML && parser.getName().equals("channel"))) {
              // if (parser.getEventType() == XmlPullParser.START_TAG) { //guranteed by nextTag
              // <!ELEMENT title (#PCDATA)>
              if(parser.getName().equals("title") && !seenBody) {
                  writer.startTag(null,"head");
                  writer.startTag(null,"title").text(parser.nextText()).endTag(null,"title");
                  writer.endTag(null,"head");
              } else if(parser.getName().equals("item")) {
                  if(!seenBody) {
                      writer.startTag(null, "body");
                      seenBody = true;
                  }
                  convertItemToHtml(parser, writer);
              } else {
                  // skip any element content including sub elements...
                  int level = 1;
                  while (level > 0) {
                      switch(parser.next()) {
                          case XmlPullParser.START_TAG: ++level; break;
                          case XmlPullParser.END_TAG: --level; break;
                      }
                  }
              }
          }
          if(seenBody) writer.endTag(null, "body");
      }
  
      public void convertItemToHtml(XmlPullParser parser, XmlSerializer writer)
          throws IOException, XmlPullParserException
      {
          writer.startTag(null, "p");
          //<!ELEMENT item (title | link | description)*>
          String title = null, link = null, description = null;
          while (parser.nextTag() != XmlPullParser.END_TAG) {
              if (parser.getName().equals("title")) {
                  title = parser.nextText();
              } else if (parser.getName().equals("link")) {
                  link = parser.nextText();
              } else if (parser.getName().equals("description")) {
                  description = parser.nextText();
              }
          }
  
          //HashMap attributes = new HashMap(1);
          //if(link != null) attributes.put("href", link);
          //writer.beginElement("a",attributes);
          writer.startTag(null, "a");
          writer.attribute(null, "href", link);
          if(title != null) {
              writer.text(title);
          } else {
              writer.text(link);
          }
          writer.endTag(null,"a");
  
          //writer.writeEmptyElement("br");
          writer.startTag(null, "br").endTag(null, "br");
  
          if(description != null) writer.text(description);
  
          writer.endTag(null, "p"); // end the "p" element
      }
  }
  
  
  
  
  1.1                  xmlpull-api-v1/src/java/samples/rss.xml
  
  Index: rss.xml
  ===================================================================
  <?xml version="1.0" encoding="ISO-8859-1"?>
  <!DOCTYPE rss PUBLIC "-//Netscape Communications//DTD RSS 0.91//EN"
                "http://my.netscape.com/publish/formats/rss-0.91.dtd">
  <rss version="0.91">
     <channel>
  
     <title>mars</title>
     <link>http://www.example.com/mars</link>
     <description>Developer news from the MARS community</description>
     <language>en-us</language>
     <copyright>Copyright 2999-3001, MARS team.</copyright>
     <managingEditor>[email protected]</managingEditor>
     <webMaster>[email protected]</webMaster>
  
        <image>
          <title>mars</title>
          <url>http://www.example.com/images/mynetscape3188.gif</url>
          <link>http://www.example.com</link>
          <width>88</width>
          <height>31</height>
          <description>News, opinions, tips and issues concerning MARS development</description>
        </image>
  
  <item>
  <title>MARS 1.0 Released</title>
  <link>http://www.example.com/read?item=3322323</link>
  <description>The latest verion of MARS survival toolkit release.</description>
  </item>
  <item>
  <title>Rapid growth of MARS confirmed</title>
  <link>http://www.example.com/read?item=334300909</link>
  <description>Independent office EARTH confirmed that MARS is growing.
  
  Another in series of astrounding NONSENSE news!
  </description>
  </item>
  
  </channel>
  </rss>