使用一个
documentFilter，这是我制作的一个示例，它将仅接受字母字符和空格：
import javax.swing.Jframe;import javax.swing.JTextField;import javax.swing.SwingUtilities;import javax.swing.text.Abstractdocument;import javax.swing.text.AttributeSet;import javax.swing.text.BadLocationException;import javax.swing.text.documentFilter;import javax.swing.text.documentFilter.FilterBypass;public class Test { public Test() { initComponents(); } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { new Test(); } }); } private void initComponents() { Jframe frame = new Jframe(); frame.setDefaultCloseOperation(Jframe.EXIT_ON_CLOSE); JTextField jtf = new JTextField(); //add filter to document ((Abstractdocument) jtf.getdocument()).setdocumentFilter(new MydocumentFilter()); frame.add(jtf); frame.pack(); frame.setVisible(true); }}class MydocumentFilter extends documentFilter { @Override public void replace(FilterBypass fb, int i, int i1, String string, AttributeSet as) throws BadLocationException { for (int n = string.length(); n > 0; n--) {//an inserted string may be more than a single character i.e a copy and paste of 'aaa123d', also we iterate from the back as super.XX implementation will put last insterted string first and so on thus 'aa123d' would be 'daa', but because we iterate from the back its 'aad' like we want char c = string.charAt(n - 1);//get a single character of the string System.out.println(c); if (Character.isAlphabetic(c) || c == ' ') {//if its an alphabetic character or white space super.replace(fb, i, i1, String.valueOf(c), as);//allow update to take place for the given character } else {//it was not an alphabetic character or white space System.out.println("Not allowed"); } } } @Override public void remove(FilterBypass fb, int i, int i1) throws BadLocationException { super.remove(fb, i, i1); } @Override public void insertString(FilterBypass fb, int i, String string, AttributeSet as) throws BadLocationException { super.insertString(fb, i, string, as); }}
