I am a relatively new Android programmer and I was wondering how you could get read text off the internet in 4.0.3. I keep finding code that gives me a Network on Main exception
In Honeycomb and Ice Cream Sandwich (i.e. Android 3.0+) , you cannot connect to the internet in the main thread (onCreate()
, onPause()
, onResume()
etc.), and you have to instead start a new thread. The reason why this has changed is because network operations can make the app wait for a long time, and if you're running them in the main thread, the whole application becomes unresponsive. If you try to connect from the main thread, Android will throw a NetworkOnMainThreadException
.
To bypass this, you can run networking code from a new thread, and use runOnUiThread()
to do things in the main thread, such as update the user interface. Generally, you can do something like:
class MyActivity extends Activity {
public onCreate(Bundle savedInstanceState) {
super.onCreate();
// Create thread
Thread networkThread = new Thread() {
@Override
public void run() {
try {
// this is where your networking code goes
// I'm declaring the variable final to be accessible from runOnUiThread
final String result = someFunctionThatUsesNetwork();
runOnUiThread(new Runnable() {
@Override
public void run() {
// this is where you can update your interface with your results
TextView myLabel = (TextView) findViewById(R.id.myLabel);
myLabel.setText(result);
}
}
} catch (IOException e) {
Log.e("App", "IOException thrown", e);
}
}
}
}
}