?

import ?javax.swing.text.AttributeSet;
 import ?javax.swing.text.BadLocationException;
 import ?javax.swing.text.PlainDocument;

 /**
*?<p>DBC?case?for?TextField</p>
*?
*? @author ?wt
*? @version ?0.01
 */
public ? class ?DBCDocument? extends ?PlainDocument {
???? private ? int ?maxchars_? = ? 32 ;
????
???? /**
?????*?
?????*? @param ?maxchars?
????? */
???? public ? void ?setMaxChars( int ?maxchars)? {
????????maxchars_? = ?maxchars;
????}
???? public ? void ?insertString( int ?offs,?String?str,?AttributeSet?a)? throws ?BadLocationException? {
???????? if ?(getLength()? + ?str.length()? > ?maxchars_)? {
???????????? return ;
????????}
????????String?newstr? = ? "" ;
???????? for ?( int ?i? = ? 0 ;?i? < ?str.length();?i ++ )? {
???????????? char ?now? = ?str.charAt(i);
???????????? if ?(now? >= ? ' \u0020 ' ? && ?now? <= ? ' \u007e ' )? {
????????????????newstr? += ?now;
????????????} ? else ? if ?(now? == ? ' \u3000 ' )? {
????????????????newstr? += ? ' \u0020 ' ;
????????????} ? else ? if ?(now? >= ? ' \uff01 ' ? && ?now? <= ? ' \uff5e ' )? {
????????????????newstr? += ?( char )(now? - ? 0xfee0 );
????????????} ? else ? {
???????????????? return ;
????????????}
????????}
???????????? super .insertString(offs,?newstr,?a);
????}
// ????public?static?void?main(String[]?args)?{
 // ????????JFrame?f?=?new?JFrame();
 // ????????JTextField?txt?=?new?JTextField(50);
 // ????????txt.setDocument(new?DBCDocument());
 // ????????f.getContentPane().add(txt);
 // ????????f.pack();
 // ????????f.show();
 // ????????f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
 // ????}
}