Android RSS Reader cuts off after first pragraph

2019-09-18 17:18发布

问题:

I am creating an app for my school newspaper and am running into a problem when trying to display the full article. Currently I have a list of articles appear that are pulled from an RSS feed, and when one is clicked on it brings up the content of the article. However only the first paragraph displays in the TextView, no matter how long it is. This leads me too believe that it has something to do with the <p></p> HTML tags. I am not that familiar with RSS feeds or parsing XML(this being my first time trying it)and have looked around for ways to do what I'm trying to accomplish.

From: Android TextView cuts off after one paragraph

I am creating this question based on results of the above question. I thought the problem with my app had something to do with the TextView and it's properties but by using plain text that I hard coded in it operates just fine.

Based on the comments and things that I tried, the problem appears to be with how the app is reading information from the RSS feed. Like I said before this is my first time working with RSS feeds in Android, and I am using a sample projects code(can be found in the previous questions). Below is the code relevant to the RSS feed:

RSSFeed.java:

public class RSSFeed {

    private String title = null;
    private String description = null;
    private String link = null;
    private String pubdate = null;
    private String content = null;
    private List<RSSItem> itemList;

    RSSFeed(){
        itemList = new Vector<RSSItem>(0);
    }

    void addItem(RSSItem item){
        itemList.add(item);
    }

    RSSItem getItem(int location){
        return itemList.get(location);
    }

    List<RSSItem> getList(){
        return itemList;
    }

    void setTitle(String value){
        title = value;
    }
    void setDescription(String value){
        description = value;
    }
    void setLink(String value){
        link = value;
    }
    void setPubdate(String value){
        pubdate = value;
    }
    public void setContent(String value) {
        content=value;
    }

    String getTitle(){
        return title;
    }
    String getDescription(){
        return description;
    }
    String getLink(){
        return link;
    }
    String getPubdate(){
        return pubdate;
    }

    String getContent() {
        return content;
    }



}

RSSHandler.java:

public class RSSHandler extends DefaultHandler {

// Feed and Article objects to use for temporary storage
private Article currentArticle = new Article();
private List<Article> articleList = new ArrayList<Article>();

// Number of articles added so far
private int articlesAdded = 0;

// Number of articles to download
private static final int ARTICLES_LIMIT = 15;

//Current characters being accumulated
StringBuffer chars = new StringBuffer();


/* 
 * This method is called every time a start element is found (an opening XML marker)
 * here we always reset the characters StringBuffer as we are only currently interested
 * in the the text values stored at leaf nodes
 * 
 * (non-Javadoc)
 * @see org.xml.sax.helpers.DefaultHandler#startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)
 */
public void startElement(String uri, String localName, String qName, Attributes atts) {
    chars = new StringBuffer();
}



/* 
 * This method is called every time an end element is found (a closing XML marker)
 * here we check what element is being closed, if it is a relevant leaf node that we are
 * checking, such as Title, then we get the characters we have accumulated in the StringBuffer
 * and set the current Article's title to the value
 * 
 * If this is closing the "Item", it means it is the end of the article, so we add that to the list
 * and then reset our Article object for the next one on the stream
 * 
 * 
 * (non-Javadoc)
 * @see org.xml.sax.helpers.DefaultHandler#endElement(java.lang.String, java.lang.String, java.lang.String)
 */
public void endElement(String uri, String localName, String qName) throws SAXException {

    if (localName.equalsIgnoreCase("title"))
    {
        Log.d("LOGGING RSS XML", "Setting article title: " + chars.toString());
        currentArticle.setTitle(chars.toString());

    }
    else if (localName.equalsIgnoreCase("description"))
    {
        Log.d("LOGGING RSS XML", "Setting article description: " + chars.toString());
        currentArticle.setDescription(chars.toString());
    }
    else if (localName.equalsIgnoreCase("pubDate"))
    {
        Log.d("LOGGING RSS XML", "Setting article published date: " + chars.toString());
        currentArticle.setPubDate(chars.toString());
    }
    else if (localName.equalsIgnoreCase("encoded"))
    {
        Log.d("LOGGING RSS XML", "Setting article content: " + chars.toString());
        currentArticle.setEncodedContent(chars.toString());
    }
    else if (localName.equalsIgnoreCase("item"))
    {

    }
    else if (localName.equalsIgnoreCase("link"))
    {
        try {
            Log.d("LOGGING RSS XML", "Setting article link url: " + chars.toString());
            currentArticle.setUrl(new URL(chars.toString()));
        } catch (MalformedURLException e) {
            Log.e("RSA Error", e.getMessage());
        }

    }




    // Check if looking for article, and if article is complete
    if (localName.equalsIgnoreCase("item")) {

        articleList.add(currentArticle);

        currentArticle = new Article();

        // Lets check if we've hit our limit on number of articles
        articlesAdded++;
        if (articlesAdded >= ARTICLES_LIMIT)
        {
            throw new SAXException();
        }
    }
}





/* 
 * This method is called when characters are found in between XML markers, however, there is no
 * guarantee that this will be called at the end of the node, or that it will be called only once
 * , so we just accumulate these and then deal with them in endElement() to be sure we have all the
 * text
 * 
 * (non-Javadoc)
 * @see org.xml.sax.helpers.DefaultHandler#characters(char[], int, int)
 */
public void characters(char ch[], int start, int length) {
    chars.append(new String(ch, start, length));
}





/**
 * This is the entry point to the parser and creates the feed to be parsed
 * 
 * @param feedUrl
 * @return
 */
public List<Article> getLatestArticles(String feedUrl) {
    URL url = null;
    try {

        SAXParserFactory spf = SAXParserFactory.newInstance();
        SAXParser sp = spf.newSAXParser();
        XMLReader xr = sp.getXMLReader();

        url = new URL(feedUrl);

        xr.setContentHandler(this);
        xr.parse(new InputSource(url.openStream()));


    } catch (IOException e) {
        Log.e("RSS Handler IO", e.getMessage() + " >> " + e.toString());
    } catch (SAXException e) {
        Log.e("RSS Handler SAX", e.toString());
    } catch (ParserConfigurationException e) {
        Log.e("RSS Handler Parser Config", e.toString());
    }

    return articleList;
}

}

RSSItem.java:

public class RSSItem {

private String title = null;
private String description = null;
private String link = null;
private String pubdate = null;
private String content = null;

RSSItem(){
}

void setTitle(String value){
    title = value;
}
void setDescription(String value){
    description = value;
}
void setLink(String value){
    link = value;
}
void setPubdate(String value){
    pubdate = value;
}
public void setContent(String value) {
    content=value;
}

String getTitle(){
    return title;
}
String getDescription(){
    return description;
}
String getLink(){
    return link;
}
String getPubdate(){
    return pubdate;
}

public String getContent() {
    return content;
}



@Override
public String toString() {
    // TODO Auto-generated method stub
    return title;
}

}

AllStoriesFragment.java:

public class AllStoriesFragment extends ListFragment {

/*********************************************************************
 * RSS Async Task
 *********************************************************************/
public class RssLoadingTask extends AsyncTask<Void, Void, Void> {

    @Override
    protected void onPostExecute(Void result) {
        // TODO Auto-generated method stub
        displayRss();
    }

    @Override
    protected void onPreExecute() {
        // TODO Auto-generated method stub
        preReadRss();
    }

    @Override
    protected void onProgressUpdate(Void... values) {
        // TODO Auto-generated method stub
        //super.onProgressUpdate(values);
    }

    @Override
    protected Void doInBackground(Void... arg0) {
        // TODO Auto-generated method stub
        readRss();
        return null;
    }

}
/*********************************************************************
 * End RSS Async Task
 *********************************************************************/

private RSSFeed myRssFeed = null;

TextView feedTitle;
TextView feedDescription;

/*********************************************************************
 * Custom Array Adapter 
 *********************************************************************/

public class MyCustomAdapter extends ArrayAdapter<RSSItem> {

        public MyCustomAdapter(Context context, int textViewResourceId, List<RSSItem> list) {
            super(context, textViewResourceId, list);
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // TODO Auto-generated method stub
            //return super.getView(position, convertView, parent);

            View row = convertView;

            if(row==null){
                LayoutInflater inflater=getActivity().getLayoutInflater();
                row=inflater.inflate(R.layout.row, parent, false);
            }
            //Set Item Title
            TextView listTitle=(TextView)row.findViewById(R.id.listtitle);
            listTitle.setText(myRssFeed.getList().get(position).getTitle());

            //Set Item PubDate
            TextView listPubdate=(TextView)row.findViewById(R.id.listpubdate);
            listPubdate.setText(myRssFeed.getList().get(position).getPubdate());

            if (position%2 == 0){
                listTitle.setBackgroundColor(0xff101010);
                listPubdate.setBackgroundColor(0xff101010);
            }
            else{
                listTitle.setBackgroundColor(0xff080808);
                listPubdate.setBackgroundColor(0xff080808);
            }

            return row;
        }
    }
    /*********************************************************************
     * End Custom Array Adapter 
     *********************************************************************/

   /** Called when the fragment is first created. */
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View v =  inflater.inflate(R.layout.fragment_allstories, null);
        Log.d("MainActivity", "AllStoriesFragment started.");

        feedTitle = (TextView)v.findViewById(R.id.feedtitle);
        feedDescription = (TextView)v.findViewById(R.id.feeddescription);
        startReadRss();

        return v ;
    }

   private void startReadRss(){
       new RssLoadingTask().execute();
   }

   private void preReadRss(){
       setListAdapter(null);

       Toast.makeText(getActivity(), "Reading RSS, Please wait.", Toast.LENGTH_LONG).show();
   }

   private void readRss(){
       try {
           URL rssUrl = new URL("http://www.campusslate.com/feed/");
           InputSource myInputSource = new InputSource(rssUrl.openStream());

           SAXParserFactory mySAXParserFactory = SAXParserFactory.newInstance();
           SAXParser mySAXParser = mySAXParserFactory.newSAXParser();

           RSSHandler myRSSHandler = new RSSHandler();

           XMLReader myXMLReader = mySAXParser.getXMLReader();

           myXMLReader.setContentHandler(myRSSHandler);
           myXMLReader.parse(myInputSource);

           myRssFeed = myRSSHandler.getFeed();
       } 
       catch (MalformedURLException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       } 
       catch (ParserConfigurationException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       } 
       catch (SAXException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       } 
       catch (IOException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       }
    }

   private void displayRss(){

       if (myRssFeed!=null){
           MyCustomAdapter adapter = new MyCustomAdapter(getActivity(), R.layout.row, myRssFeed.getList());
           setListAdapter(adapter);
       }
   }


   public void onListItemClick(ListView l, View v, int position, long id) {
       // TODO Auto-generated method stub
       Intent intent = new Intent(getActivity(), ShowDetails.class);
       intent.putExtra("keyPubdate", myRssFeed.getItem(position).getPubdate());
       intent.putExtra("keyLink", myRssFeed.getItem(position).getLink());
       intent.putExtra("keyTitle", myRssFeed.getItem(position).getTitle());
       intent.putExtra("keyContent", myRssFeed.getItem(position).getContent());
       startActivity(intent);
   }

   @Override
   public boolean onOptionsItemSelected(MenuItem item) {
    // TODO Auto-generated method stub
    switch(item.getItemId()){
    case (0): readRss();
      break;
    default:
      break;
    }

    return true;
   }
}

ShowDetails.java is posted in the other question, though the code may be slightly different from what I have currently. The issue now is that every item in the list is the last item read from the RSS Feed.

Would post an image if I had enough reputation.

回答1:

An XML element may have multiple text nodes. Your code assumes that there is only one. Please use an append operation, not a set operation, in your characters() callback.