Javase Project event class (ItemEvent)

{Related Information}
The Project event class (ItemEvent) refers to a semantic event that an item is selected and canceled. Selecting a CheckBox, ComboBox, List , Choice , and other components will result in a project event. Using Project events, you must add an event handler that implements the ItemListener interface to the component, which has the following methods:
void Itemstatechange (ItemEvent e)

{Specific Instance description}
function description, each item selected will display relevant information in the text area, as follows:

{Specific Instance code}

 PackageSup.orange.learn;Importjava.awt.*;Importjava.awt.event.ItemEvent;ImportJava.awt.event.ItemListener;ImportJava.awt.event.WindowAdapter;Importjava.awt.event.WindowEvent;/*** Created by Re-x on 10/30/14.*/ Public classItemeventdemoextendsFrameImplementsitemlistener{list List;    Checkbox CheckBox1, CheckBox2, Checkbox3;    Choice Colorchooser;    TextArea TextArea;  PublicItemeventdemo () {Super();    Init (); }     Public Static voidMain (string[] args) {NewItemeventdemo (); }     Public voidinit () {setlayout (NewGridLayout (4, 1)); TextArea=NewTextArea ();        Add (textarea); List=NewList (4,false); List.add ("Chinese"); List.add ("Math"); List.add ("中文版"); List.add ("Physics"); List.add ("Chemistry"); List.add ("History"); List.add ("Geography");        Add (list); List.additemlistener ( This); Panel Panel=NewPanel (); CheckboxGroup CBG=NewCheckboxGroup (); CheckBox1=NewCheckBox ("One", CBG,true); Checkbox1.additemlistener ( This);        Panel.add (CheckBox1); CheckBox2=NewCheckBox ("Both", CBG,false); Checkbox2.additemlistener ( This);        Panel.add (CHECKBOX2); Checkbox3=NewCheckBox ("Three", CBG,true); Checkbox3.additemlistener ( This);        Panel.add (CHECKBOX3);        Add (panel); Colorchooser=NewChoice (); Colorchooser.add ("Red"); Colorchooser.add ("Green"); Colorchooser.add ("Black"); Colorchooser.additemlistener ( This);        Add (Colorchooser); Addwindowlistener (NewWindowadapter () {@Override Public voidwindowclosing (windowevent e) {Super. windowclosing (e);                Dispose (); System.exit (0);        }        }); SetSize (300, 500); SetVisible (true); }     Public voiditemstatechanged (itemevent e) {if(E.getsource () = =list)        {Textarea.settext (List.getselecteditem ()); }        Else if(E.getsource () = =CheckBox1)        {Textarea.settext (Checkbox1.getlabel ()); }        Else if(E.getsource () = =checkbox2)        {Textarea.settext (Checkbox2.getlabel ()); }        Else if(E.getsource () = =checkbox3)        {Textarea.settext (Checkbox3.getlabel ()); }        Else if(E.getsource () = =Colorchooser)        {Textarea.settext (Colorchooser.getselecteditem ()); }    }}

Javase Project event class (ItemEvent)