OkHttpClient doesn't work for "http" urls ("http://www.example.com") but works for "https" urls ("https://www.example.com")

Question

This code runs the onFailure function.

OkHttpClient client;
client = new OkHttpClient();

here the url is a http url.

Request request = new Request.Builder().url("http://www.example.com").build();

client.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                e.printStackTrace();
                textView.setText("Failed to get response");
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                if(response.isSuccessful()){
                    final String myResponse = response.body().string();
                    MainActivity.this.runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            textView.setText(myResponse);
                        }
                    });
                }
            }
        });

but when url is a https url like Request request = new Request.Builder().url("https://www.example.com").build(); then onResponse is called.

How can make this work for http websites. The website I need this to work on is a http only website.