Leap Year test program

When illegal input is not considered:

Import Javafx.application.application;import Javafx.event.actionevent;import Javafx.event.eventhandler;import Javafx.scene.scene;import Javafx.scene.control.button;import Javafx.scene.control.textfield;import Javafx.scene.layout.anchorpane;import Javafx.scene.layout.hbox;import Javafx.scene.text.text;import    Javafx.stage.stage;public class Test extends application{public static void main (string[] args) {test.launch (args);                  } public void Start (stage stage) {Stage.settitle ("Year testing");        Anchorpane root = new Anchorpane ();        HBox hbox1 = new HBox (8);        Text text = new text ("The number of Year:");        Final text result = new text ();        Final TextField tf = new TextField ();        Button btn = New button ("Enter");                 Hbox1.getchildren (). AddAll (text, TF, BTN); Btn.setonaction (New eventhandler<actionevent> () {@Override public void handle (ActionEvent actevt) {if (check (Integer.parseint (tf.geTtext ())) Result.settext (Integer.parseint (Tf.gettext ()) + "good");                Else Result.settext (Integer.parseint (Tf.gettext ()) + "bad");                }        });        Anchorpane.settopanchor (Hbox1, 60.0);        Anchorpane.setleftanchor (Hbox1, 30.0);                Root.getchildren (). Add (Hbox1);        Anchorpane.settopanchor (result, 90.0);        Anchorpane.setleftanchor (result, 30.0); Root.getchildren ().

Add (result);                Stage.setscene (The new Scene (root, N.));        Stage.show ();     }         public boolean check (int num) {    Boolean re = false;    if (num% 4) = = 0)    re = true;    if (num%) = = 0)    re = false;    if (num%) = = 0)    re = true;        return re;    }}

Normal input:

Illegal input:

Cause Analysis:

The use of the Integer.parseint (Tf.gettext ()) function does not take into account the case of illegal input.

Improved:

Btn.setonaction (New eventhandler<actionevent> () {        @Override public            void handle (ActionEvent actevt) {        try{        if (check (Integer.parseint (Tf.gettext ()))            Result.settext (Integer.parseint (Tf.gettext ()) + " Good ");            else            Result.settext (Integer.parseint (Tf.gettext ()) + "bad");                    }        catch (Exception e) {        result.settext ("illegal input!");}}        );

Effect:

Leap Year test program