java - How to show a notification to the user if a textfield is left blank -

java - How to show a notification to the user if a textfield is left blank -

how can show joptionpane notification user when textfield left blank?

i new java

i made button submit name, , if user submits blank, gets blank also. there method textfield determine whether textfield blank or not, can give alert textfield blank joptionpane?

in button's actionlistener:

if (textfield.gettext().isempty()) { joptionpane.showmessagedialog(textfield, "beware: left text field blank"); } else { proceedasusual(); }

java input textfield