android:digits not allowing next button in keypad

Add android:imeOptions="actionNext" in your EditText in xml

<EditText
        android:id="@+id/et_count"
        android:layout_width="100dp"
        android:singleLine="true"
        android:imeOptions="actionNext"
        android:layout_height="wrap_content" />

You can make use of the imeOptions attribute available for EditText in xml.

Try the following. It worked in my case.

In XML:

 <EditText
      android:id="@+id/edit_text1"
      android:layout_width="match_parent"
      android:layout_height="45dp"
      android:digits="abcdefghijklmnopqrstuvwxyz. " 
      android:imeOptions="actionNext"/>

<EditText
      android:id="@+id/edit_text2"
      android:layout_width="match_parent"
      android:layout_height="45dp"/>

Then, in JAVA:

    EditText edit_text1 = (EditText) findViewById (R.id.edit_text1);

    EditText edit_text2 = (EditText) findViewById (R.id.edit_text2);

    edit_text1.setOnEditorActionListener(new OnEditorActionListener() {     
        @Override
        public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {

            boolean handled = false;

            if (actionId == EditorInfo.IME_ACTION_NEXT) {
                edit_text2.requestFocus();
                handled = true;
            }

            return handled;
       }
   });