CODEWITHSUNDEEP
javaandroidmultithreadinguser-interfaceasynchronous
Josh
Josh

Reputation: 12566

Android - Correct Multithreading / UI updating

I have an application that will be accessing the web. I've decided to use Spring Android as the RestAPI, and with the help of a Thread have got this simple demo working. My question is, how do I go about changing it to populating an actual ListView rather than just logging the output of the object? Some other questions on here have led me to believe that AsyncTask may be the answer, but I'm still a bit confused as to how I update the UI, as it is my understanding that other threads can't touch it.

Here is what I have now, minus the function that creates the RestTemplate, and makes the request, as I believe it is not relevant:

  public void onCreate( Bundle savedInstanceState )
  {
    super.onCreate( savedInstanceState );

    new Thread( new Runnable() {
      public void run()
      {
        // create a RestTemplate. This is used to communicate with the server.
        RestTemplate restTemplate = getRestTemplate();

        String url = "http://192.168.2.14:8888/";

        JSONData[] jsonData = restTemplate.getForObject( url, JSONData[].class );

        for( JSONData d : jsonData )
        {
          Log.d( "TEST", d.getName() + " " + d.getId() );
        }
      }
    } ).start();

    setContentView( R.layout.main );
  }

Upvotes: 1

Views: 674

Answers (2)

MByD
MByD

Reputation: 137322

There are several options, listed in the very nice article (Android) Painless Threading. AsyncTask is one of the options and it seems to fit your needs, and there are several methods of it that run on the UI thread, such as onPreExecute, onPostExecute and onProgressUpdate.

Upvotes: 2

Blackbelt
Blackbelt

Reputation: 157447

if want to change the UI from a different thread, you can use Handler or Activity.runOnUiThread().

Upvotes: 4

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