Xml Parsing to android ListView Using IBM example

Question

Im trying to make a Manga Rss-Reader app using the XmlPullParser that was used in this IBM example. I have taken the IBM source code and only changed the feedURL to "http://fandom.com/rss/new/manga" and the PUB_DATE string in all files has been changed to PUBDATE instead. Still I cant get the app to run correctly.

For reference I have renamed the source Otaku as I plan to use it as the base for a new app. It's supposed to show this Rss feed as a ListView but I dont understand where the problem lies. I happen to be logcat illiterate :(. my log cat states:

07-29 13:24:17.963: E/Trace(670): error opening trace file: No such file or directory(2)
07-29 13:24:18.113: W/ActivityThread(670): Application com.mypacks.activities.otaku is waiting for the debugger on port 8100...
07-29 13:24:18.133: I/System.out(670): Sending WAIT chunk
07-29 13:24:18.133: I/dalvikvm(670): Debugger is active
07-29 13:24:18.333: I/System.out(670): Debugger has connected
07-29 13:24:18.333: I/System.out(670): waiting for debugger to settle...
07-29 13:24:18.533: I/System.out(670): waiting for debugger to settle...
07-29 13:24:18.733: I/System.out(670): waiting for debugger to settle...
07-29 13:24:18.943: I/System.out(670): waiting for debugger to settle...
07-29 13:24:19.171: I/System.out(670): waiting for debugger to settle...
07-29 13:24:19.386: I/System.out(670): waiting for debugger to settle...
07-29 13:24:19.646: I/System.out(670): waiting for debugger to settle...
07-29 13:24:19.857: I/System.out(670): waiting for debugger to settle...
07-29 13:24:20.089: I/System.out(670): debugger has settled (1518)
07-29 13:24:20.753: I/AndroidNews(670): ParserType=XML_PULL
07-29 13:24:20.903: E/AndroidNews(670): android.os.NetworkOnMainThreadException
07-29 13:24:20.903: E/AndroidNews(670): java.lang.RuntimeException: android.os.NetworkOnMainThreadException
07-29 13:24:20.903: E/AndroidNews(670):     at com.mypacks.internals.otaku.XmlPullFeedParser.parse(XmlPullFeedParser.java:57)
07-29 13:24:20.903: E/AndroidNews(670):     at com.mypacks.internals.otaku.MessageList.loadFeed(MessageList.java:77)
07-29 13:24:20.903: E/AndroidNews(670):     at com.mypacks.internals.otaku.MessageList.onCreate(MessageList.java:33)
07-29 13:24:20.903: E/AndroidNews(670):     at android.app.Activity.performCreate(Activity.java:5008)
07-29 13:24:20.903: E/AndroidNews(670):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
07-29 13:24:20.903: E/AndroidNews(670):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
07-29 13:24:20.903: E/AndroidNews(670):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
07-29 13:24:20.903: E/AndroidNews(670):     at android.app.ActivityThread.access$600(ActivityThread.java:130)
07-29 13:24:20.903: E/AndroidNews(670):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
07-29 13:24:20.903: E/AndroidNews(670):     at android.os.Handler.dispatchMessage(Handler.java:99)
07-29 13:24:20.903: E/AndroidNews(670):     at android.os.Looper.loop(Looper.java:137)
07-29 13:24:20.903: E/AndroidNews(670):     at android.app.ActivityThread.main(ActivityThread.java:4745)
07-29 13:24:20.903: E/AndroidNews(670):     at java.lang.reflect.Method.invokeNative(Native Method)
07-29 13:24:20.903: E/AndroidNews(670):     at java.lang.reflect.Method.invoke(Method.java:511)
07-29 13:24:20.903: E/AndroidNews(670):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
07-29 13:24:20.903: E/AndroidNews(670):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
07-29 13:24:20.903: E/AndroidNews(670):     at dalvik.system.NativeStart.main(Native Method)
07-29 13:24:20.903: E/AndroidNews(670): Caused by: android.os.NetworkOnMainThreadException
07-29 13:24:20.903: E/AndroidNews(670):     at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)
07-29 13:24:20.903: E/AndroidNews(670):     at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
07-29 13:24:20.903: E/AndroidNews(670):     at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
07-29 13:24:20.903: E/AndroidNews(670):     at java.net.InetAddress.getAllByName(InetAddress.java:214)
07-29 13:24:20.903: E/AndroidNews(670):     at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70)
07-29 13:24:20.903: E/AndroidNews(670):     at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
07-29 13:24:20.903: E/AndroidNews(670):     at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:341)
07-29 13:24:20.903: E/AndroidNews(670):     at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
07-29 13:24:20.903: E/AndroidNews(670):     at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
07-29 13:24:20.903: E/AndroidNews(670):     at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:315)
07-29 13:24:20.903: E/AndroidNews(670):     at libcore.net.http.HttpEngine.connect(HttpEngine.java:310)
07-29 13:24:20.903: E/AndroidNews(670):     at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:289)
07-29 13:24:20.903: E/AndroidNews(670):     at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:239)
07-29 13:24:20.903: E/AndroidNews(670):     at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:273)
07-29 13:24:20.903: E/AndroidNews(670):     at libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:168)
07-29 13:24:20.903: E/AndroidNews(670):     at com.mypacks.internals.otaku.BaseFeedParser.getInputStream(BaseFeedParser.java:36)
07-29 13:24:20.903: E/AndroidNews(670):     at com.mypacks.internals.otaku.XmlPullFeedParser.parse(XmlPullFeedParser.java:19)
07-29 13:24:20.903: E/AndroidNews(670):     ... 16 more
07-29 13:24:21.173: I/Choreographer(670): Skipped 44 frames!  The application may be doing too much work on its main thread.
07-29 13:24:21.223: D/gralloc_goldfish(670): Emulator without GPU emulation detected.

Answer 1

This is the important bit from your logcat:

Caused by: android.os.NetworkOnMainThreadException

That is telling you that you are trying to make your network request to get the RSS feed from the main thread.

Starting with Honeycomb (IIRC) doing net requests on the main thread will throw an exception because the platform creators wanted to give you a reminder that network operations should not take place on the main thread.

The quickets way to "fix" this is to build your application for a lower API level.

The more correct solution is to move your network operation onto its own background thread. One way to do so is to change the onCreate() method in your RSSReader activity to look like this:

private RSSFeed feed = null;
private Handler h;

public void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    setContentView(R.layout.main);
    //Set up a Handler to call updateDisplay() once the feed has been fetched.
    h = new Handler(){
        @Override
        public void handleMessage(Message msg){
            // display UI
            UpdateDisplay();
        }
    };


    Thread t = new Thread() {
        @Override
        public void run() {

            // go get our feed!
            feed = getFeed(RSSFEEDOFCHOICE);
            //Send a signal to the handler to tell it that we are done fetching the feed.
            h.sendEmptyMessage(0);

        }
    };
    t.start();

}

Another way you could do this is with an AsyncTask.

This Lars Vogella blog post is a GREAT resource to use when learning about both Thread/Handler and AsyncTask.