When there are one or more EditText in the activity, a soft keyboard automatically appears when the activity is launched, which hides some visible portion of the screen and we don't always have a requirement to automatically pop-up the soft input keyboard. We can solve this by editing Manifest.xml file. Add the following attribute inside the particular Activity tag in Manifest.xml file -

android:windowSoftInputMode="stateAlwaysHidden"

It will keep the Keyboard hidden when the activity is resumed.

or, in your Activity class call the following method -

getWindow().setSoftInputMode(
    WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);

You can also close a keyboard on any event like on button click by using InputMethodManager class by calling hideSoftInputFromWindow and passing the desired parameters -

 View view = this.getCurrentFocus();
    if (view != null) {
        InputMethodManager inputManager = (InputMethodManager) this.getSystemService(Context.INPUT_METHOD_SERVICE);
        inputManager.hideSoftInputFromWindow(view.getWindowToken(), 0);
    }