I need to find these libraries

To ensure that the clipboard has the right content you could use this code to paste.

import android.content.ClipDescription;

// Paste string from clipboard
  if (clipboard.hasPrimaryClip()) {
    android.content.ClipDescription description = clipboard.getPrimaryClipDescription();
    android.content.ClipData data = clipboard.getPrimaryClip();
    if (data != null && description != null && description.hasMimeType(ClipDescription.MIMETYPE_TEXT_PLAIN)) {
      String str_paste = String.valueOf(data.getItemAt(0).getText());
      text(str_paste, width/2, height/2);
    }
  }