How is it possible to have feeds from different Urls in the same ListView

android, feed, listview, url

Solution

I am exactly doing this in my app,

This is how i am doing this, I have created `AsyncTask` to parse RSS, and using a loop to pass different URLs to be parsed to `AysncTask`.

Here is what I mean,

This is the array of URL,

private String[] newsURLs = {
            "url1", "url2", "url3" };

this is how I am executing them,

//GetNews is AsyncTask class
for (int i = 0; i < newsURLs.length; i++) {
                GetNews blog = new GetNews(i);
                blog.execute();
            }

In the above code `i`is the URL number passed in as a constructor in `AsyncTask` class.

Here is my constructor in `AsyncTask` class,

int number;
public GetNews(int urlNumber) {
            number = urlNumber;
        }

and loading the URL in `AsyncTask`'s `doInBackground()` method this way,

                URL feedURL = new URL(newsURLs[number]);
                HttpURLConnection connection;
                connection = (HttpURLConnection) feedURL.openConnection();
                connection.setConnectTimeout(8000);
                connection.connect();

After that, I am using `SAXParser` to parse `xml` based on my need.

Please note that if you want parallel execution, replace `blog.execute();` with

blog.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);

// this type of executor uses the following params:
            //
            // private static final int CORE_POOL_SIZE = 5;
            // private static final int MAXIMUM_POOL_SIZE = 128;
            // private static final int KEEP_ALIVE = 1;
            //
            // private static final ThreadFactory sThreadFactory = new ThreadFactory() {
            //     private final AtomicInteger mCount = new AtomicInteger(1);
            //
            //     public Thread newThread(Runnable r) {
            //         return new Thread(r, "AsyncTask #" + mCount.getAndIncrement());
            //     }
            // };
            //
            // private static final BlockingQueue<Runnable> sPoolWorkQueue =
            //        new LinkedBlockingQueue<Runnable>(10);

Also note that,

When first introduced, AsyncTasks were executed serially on a single background thread. Starting with DONUT, this was changed to a pool of threads allowing multiple tasks to operate in parallel. After HONEYCOMB, it is planned to change this back to a single thread to avoid common application errors caused by parallel execution. If you truly want parallel execution, you can use the executeOnExecutor(Executor, Params...) version of this method with THREAD_POOL_EXECUTOR; however, see commentary there for warnings on its use.

DONUT is Android 1.6, HONEYCOMB is Android 3.0.

You may also execute the task based on what version you have,

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
    blog.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
} else {
    blog.execute();
}

This is my partial code to show what I am doing,

    // This is my Main class

private String[] newsURLs = {
            "url1", "url2", "url3" };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_myapp);


            for (int i = 0; i < newsURLs.length; i++) {
                GetNews blog = new GetNews(i);
                blog.execute();
            }
        }
    }

This is `AsyncTask` class (partial code),

private class GetNews extends
        AsyncTask<Object, Void, Void> {

    protected int number;

    public GetNews(int urlNumber) {
        number = urlNumber;
    }

    @Override
    protected void doInBackground(
            Object... arg0) {

        try {
            // Check if the feed is Live
            URL feedURL = new URL(newsURLs[number]);
            HttpURLConnection connection;
            connection = (HttpURLConnection) feedURL.openConnection();
            connection.setConnectTimeout(8000);
            connection.connect();

Problem

Original source