java - JOptionPane#showMessageDialog causes an application freeze -

i need show information message user , use following code purpose:

joptionpane.showmessagedialog(null, "message", "result", joptionpane.information_message); 

but program loops or don't know on string of code. no matter insead of "message" still got app frozen. didn't done string of code changed ide eclipse , imports might have changed. checked , see import in class joption: import javax.swing.joptionpane;.

what may wrong or how check wrong?

try changing

joptionpane.showmessagedialog(null, "message", "result", joptionpane.information_message);  

to

joptionpane.showmessagedialog(this, "message", "result", joptionpane.information_message);