JTextField只允许输入数字和字母

浅浅的花香味﹌ 2022-09-07 09:39 349阅读 0赞

JTextField timeText = new JTextField(2);
    timeText.addKeyListener(new KeyListener() {
    	@Override
    	public void keyTyped(KeyEvent e) {
    
    	}
    
    	@Override
    	public void keyPressed(KeyEvent e) {
    
    	}
    
    	@Override
    	public void keyReleased(KeyEvent e) {
    		Object o = e.getSource();
    		if (o instanceof JTextField) {
    			char keyCh = e.getKeyChar();
    
    			Pattern pat = Pattern.compile("[0-9]|[a-z]|[A-Z]");
    			if (!pat.matcher(String.valueOf(keyCh)).matches()) {
    				if (keyCh != ' ')   //回车字符
    					e.setKeyChar('\0');
    			}
    		}
    	}
    });

# JAVA SWING中JTextField限制只能输入数字 #

import java.awt.Toolkit;
    import javax.swing.text.AttributeSet;
    import javax.swing.text.BadLocationException;
    import javax.swing.text.PlainDocument;
    
    public class NumberDocument extends PlainDocument {
        public NumberDocument() {
        }
    
        public void insertString(int var1, String var2, AttributeSet var3) throws BadLocationException {
            if (this.isNumeric(var2)) {
                super.insertString(var1, var2, var3);
            } else {
                Toolkit.getDefaultToolkit().beep();
            }
    
        }
    
        private boolean isNumeric(String var1) {
            try {
                Long.valueOf(var1);
                return true;
            } catch (NumberFormatException var3) {
                return false;
            }
        }
    }

使用的时候，调用JTextFile的setDocument将NumberDocument设置好就可以了。

JTextField jtextField = new JTextField();
    jtextField.setDocument(new NumberDocument());