JSpinner和double用点或逗号作为分隔符

Question

我想允许"逗号"和"点"两者作为分隔符.

我可以在string中使用replace方法只获得一个分隔符,但问题是double值是JSpinner的值,我无法找到允许两个分隔符的任何方法.如果我将语言环境设置为例如法语只允许一个分隔符.

Answer 1

只需使用自定义格式化程序即可JFormattedTextField，如下面的DefaultEditor代码JSpinner：

import java.text.ParseException;
import javax.swing.JFormattedTextField;
import javax.swing.JFormattedTextField.AbstractFormatter;
import javax.swing.JFormattedTextField.AbstractFormatterFactory;
import javax.swing.JFrame;
import javax.swing.JSpinner;
import javax.swing.JSpinner.DefaultEditor;
import javax.swing.SpinnerNumberModel;

public class Main {
    public static class CommmaDotFormatter extends AbstractFormatter {
        private boolean useComma = false;

        @Override
        public Object stringToValue(String text) throws ParseException {
            if (text == null || text.trim().isEmpty())
                throw new ParseException("Null or empty text.", 0);
            try {
                useComma = (text.contains(",") && (text.indexOf(',') == text.lastIndexOf(',')));
                return Double.valueOf(useComma? text.replace(',', '.'): text);
            }
            catch (final NumberFormatException nfx) {
                //Find the location of the error (so as to generate appropriate ParseException):
                int i = 0;
                for (final int cp: text.codePoints().toArray()) {
                    if (!Character.isDigit(cp) && cp != ',' && cp != '.')
                        throw new ParseException("Failed to parse text \"" + text + "\".", i);
                    ++i;
                }
                //Could happen if the text is composed by digits and more than one dot/comma:
                throw new ParseException("Failed to parse text \"" + text + "\".", 0);
            }
        }

        @Override
        public String valueToString(final Object value) throws ParseException {
            final String text = String.format("%.2f", value);
            return useComma? text: text.replace(',', '.');
        }
    }

    public static class CommmaDotFormatterFactory extends AbstractFormatterFactory {
        @Override
        public AbstractFormatter getFormatter(final JFormattedTextField tf) {
            if (!(tf.getFormatter() instanceof CommmaDotFormatter))
                return new CommmaDotFormatter();
            return tf.getFormatter();
        }
    }

    public static void main(final String[] args) {
        final JSpinner spin = new JSpinner(new SpinnerNumberModel(0, -10, 10, 0.01));

        ((DefaultEditor) spin.getEditor()).getTextField().setFormatterFactory(new CommmaDotFormatterFactory());

        final JFrame frame = new JFrame("JSpinner infinite value");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(spin);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }
}

注意：属性useComma可以省略。它的存在只是为了维护用户最后输入的状态。例如，如果用户输入带有逗号而不是点的值，则旋转器将继续用逗号旋转。点也一样。用户输入的任何内容都将保留为未来的值，当然他/她可以随时再次更改。但即使没有这个属性，你的问题也可以得到满足：你只需要text.replace(',', '.')每次将给定的文本stringToValue解析为double.