Okhttp response callbacks on the main thread

From my understanding, Okhttp callbacks run on the main thread so why do I get this error ?

This is not true. Callbacks run on a background thread. If you want to immediately process something in the UI you will need to post to the main thread.

Since you already have a wrapper around the callback you can do this internally in your helper so that all HttpCallback methods are invoked on the main thread for convenience.

As Jake Wharton suggested, I had to run the callbacks on the main thread explicitly.

So I wrapped the calls to the callbacks with Runnable like this:

private void call(String method, String url, final HttpCallback cb) {    ...    client.newCall(request).enqueue(new Callback() {            Handler mainHandler = new Handler(context.getMainLooper());            @Override            public void onFailure(Request request,final Throwable throwable) {                mainHandler.post(new Runnable() {                    @Override                    public void run() {                        cb.onFailure(null, throwable);                    }                });            }            @Override            public void onResponse(final Response response) throws IOException {                mainHandler.post(new Runnable() {                    @Override                    public void run() {                        if (!response.isSuccessful()) {                            cb.onFailure(response, null);                            return;                        }                        cb.onSuccess(response);                    }                });            }        }); }

I know it's an old question, but recently I encountered the same issue. If you need to update any view, you will need to use runOnUiThread() or post the result back on the main thread.

HttpUtil.get(url, new Callback() { //okhttp3.Callback   @Override   public void onFailure(Call call, IOException e) { /* Handle error **/ }   @Override   public void onResponse(Call call, Response response) throws IOException {      String myResponse =  response.body().string();      //Do something with response      //...      MyActivity.this.runOnUiThread(new Runnable() {            @Override            public void run() {               //Handle UI here                                       findViewById(R.id.loading).setVisibility(View.GONE);                            }        });   }});