Java – How to make my Android app quickly

In my android app I use 5 APIs in a class, calling them one by one in onCreate, but this makes my app slower, how to optimize my code to make it faster.

My code looks like this.

    @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

API1();
      API2();
      API3();
      API4();
      API5();
   }

 all the Apis are call in onCreate

public void API1() {
            FetchData fetch = new FetchData(this);
            fetch.response = new FetchListener() {
        @Override
        public void fetchFinish(String output) {
            try {
                JSONObject jobjOUT = new JSONObject(output);

JSONArray jsarray = jobjOUT.getJSONArray("details");

for (int i = 0; i < jsarray.length(); i++) {
                    JSONObject obj = jsarray.getJSONObject(i);
                    String a = obj.getString("abc");
                }

} catch (Exception e) {
                 TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    };
    try {
        fetch.execute("http://example.com/api/something.php?param=xyz");
    } catch (Exception e) {
         TODO Auto-generated catch block
        e.printStackTrace();
    }

}
  public void API2() {
      same code here
  }
  public void API3() {
      same code here
  }
  public void API4() {
      same code here
  }
  public void API5() {
      same code here
  }

}

My question is can I call all the APIs at the same time instead of calling them one by one? Please give me some suggestions to optimize my code.
Thank you

Try using a thread pool executor
Quotethis sum this to learn and understand. By using thread pool executors, you can run several tasks at the same time, or we can say parallel.

private void startAsyncTaskInParallel(MyAsyncTask task) {
    if(Build.VERSION.SDK_INT >= Build.VERSION_CODES. HONEYCOMB)
        task.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
    else
        task.execute();
}