如何在Android中的ListView中显示已解析的html

Question

I'm trying to parse news titles from a website using jsoup and display them in a ListView. I have been trying to solve this problem for a long time and have googled like crazy but i am unable to solve my problem or find a working solution. I have a custom class that holds two variables the news title and the link to the article. It seems as if everything parses fine but I just can't get my ListView to display correctly or at all... it continually crashes and it seams that every time I get a different error. Maybe I am making it too hard on myself. I am frustrated and can't think logically anymore... I would really appreciate any and all tips or helpful answers.

Feeds class:

public class Feeds {

private String mNewsTitle;
private String mNewsLink;

public Feeds(String newsTitle, String newsLink){
    mNewsTitle = newsTitle;
    mNewsLink = newsLink;
 }

public String getNewsTitle(){
    return mNewsTitle;
 }

public void setNewsTitle(String newsTitle){
    mNewsTitle = newsTitle;
 }

public String getNewsLink(){
    return mNewsLink;
 }

public void setNewsLink(String newsLink){
    mNewsTitle = newsLink;
 }
}

NewsFeeds class:

public class NewsFeeds extends ListActivity {

private ArrayList<Feeds> mFeedDB = new ArrayList<Feeds>();

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_news_feeds);

    HtmlParser htmlThread = new HtmlParser();
    htmlThread.execute();


} // end on create

public class HtmlParser extends AsyncTask<Void, Integer, ArrayList<Feeds>> {

    private static final int NETWORK_NO_ERROR = -1;
    private static final int NETWORK_HOST_UNREACHABLE = 1;
    private static final int NETWORK_NO_ACCESS_TO_INTERNET = 2;
    private static final int NETWORK_TIME_OUT = 3;

    Integer serverError = NETWORK_NO_ERROR;

    ProgressDialog dialog;

    protected void onPreExecute() {
        // example of setting up something
        dialog = new ProgressDialog(NewsFeeds.this);
        dialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
        dialog.setMessage("Retrieving News Feeds");
        dialog.show();
    } // end onPreExecute

    @Override
    protected ArrayList<Feeds> doInBackground(Void... params) {
        try {
            // need http protocol
            Document doc = Jsoup.connect("http://baseball-potsdam.de/news")
                    .get();

            // get news feed titles
            Elements newsFeed = doc.getElementsByClass("gdlr-blog-title");

            // get all links
            Elements links = newsFeed.select("a[href]");


            for (Element link : links) {
                // populate ArrayList with news titles and links
                mFeedDB.add(new Feeds(link.text(), link.attr("href")));
            }

            return mFeedDB;

            // } catch (IOException e) {
            // e.printStackTrace();
        } catch (ConnectException e) {
            serverError = NETWORK_NO_ACCESS_TO_INTERNET;
            return null;
        } catch (UnknownHostException e) {
            serverError = NETWORK_HOST_UNREACHABLE;
            return null;
        } catch (SocketTimeoutException e) {
            serverError = NETWORK_TIME_OUT;
            return null;
        } catch (IOException e) {
            e.printStackTrace();
        } // end try catch
        return null;

    } // end doInBackground

    protected void onProgressUpdate(Integer... progress) {

    } // end onProgressUpdate

    protected void onPostExecute(ArrayList<Feeds> result) {
        if (result != null) {

            ListView listview = (ListView) findViewById(R.id.list_view_news_feeds);
            listview.setAdapter(new ArrayAdapter<Feeds>(NewsFeeds.this, android.R.layout.simple_list_item_1 , mFeedDB));


            if (dialog.isShowing()) {
                dialog.dismiss();
            } // end if
        } else {
            switch (serverError) {
            case NETWORK_NO_ERROR:
                Toast.makeText(NewsFeeds.this,
                        "Probably, invalid response from server",
                        Toast.LENGTH_LONG).show();
                break;
            case NETWORK_NO_ACCESS_TO_INTERNET:
                // You can customize error message (or behavior) for
                // different type of error
            case NETWORK_TIME_OUT:
            case NETWORK_HOST_UNREACHABLE:
                Toast.makeText(NewsFeeds.this, "Error in Connection",
                        Toast.LENGTH_LONG).show();
                break;
            }
        } // end if else
        } // end onPostExecute
    } // end HtmlParser class
} // end NewsFeeds

activity_news_feeds.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >   

    <ListView
        android:id="@+id/list_view_news_feeds"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" 
        android:dividerHeight="0.1dp"
        android:divider="#0000CC"
    />
</LinearLayout>

NewsManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.kylehopeman.android.porcupinesnews"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="21" />

    <uses-permission android:name="android.permission.INTERNET" />"

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.kylehopeman.android.porcupinesnews.MainMenu"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity
            android:name="com.kylehopeman.android.porcupinesnews.NewsFeeds"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="com.kylehopeman.android.porcupinesnews.NewsFeeds" />
             <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>      
    </application>
</manifest>

Answer 1

If you are getting an error with the ListView it looks like it only gets instantiated in the postExecute block. Is it possible to instantiate it in the onCreate() and have it declared where you declare mFeedDB?

Answer 2

After changing the first line in my NewsFeeds.java file from:

public class NewsFeeds extends ListActivity

to:

public class NewsFeeds extends Activity

the errors went away, the app compiled and worked just like I wanted it to.