我有一个数字 JSpinner，它接受特定测量单位的值。现在，我想要一个特殊的 JSpinner 行为：如果用户输入一个数值并附加一个特定的测量单位字符串（例如“英寸”、“皮卡”），那么输入的数值必须转换为另一个值（取决于在单位字符串上）。当用户离开微调器字段（失去焦点）或以任何方式发生“commitEdit”时，必须发生这种转换。
我尝试了几种变体：自定义文档过滤器、自定义格式实例和微调器 JFormattedTextField 的自定义文本字段文档。但是我没有找到任何“挂钩”JFormattedTextField 的“commitEdit”方法调用的可能性。
实现我的要求的最佳方法是什么？有没有简单的方法来做到这一点？
还有一些其他的东西可以让你在用户输入被提交之前修改它：它是commitEdit方法本身（of JFormattedTextFieldof DefaultEditorthe JSpinner）。在里面commitEdit你可以看到'sstringToValue的方法被调用了。这意味着，如果您为文本字段提供自己的自定义，它可以将任何字符串转换为值，并将值转换为任何字符串。这是异常发生的地方，以指示提交是否失败。JFormattedTextFieldAbstractFormatterAbstractFormatter
因此，AbstractFormatter按照您的要求，按照自定义处理不同的单位：
import java.text.ParseException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
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 MilliMeterMain {
public static enum Unit {
MM(1), //Millimeters.
IN(25.4), //Inches (1 inch == 25.4 mm).
FT(25.4 * 12), //Feet (1 foot == 12 inches).
YD(25.4 * 12 * 3); //Yards (1 yard == 3 feet).
private final double factorToMilliMeters; //How much of this Unit composes a single millimeter.
private Unit(final double factorToMilliMeters) {
this.factorToMilliMeters = factorToMilliMeters;
}
public double getFactorToMilliMeters() {
return factorToMilliMeters;
}
public double toMilliMeters(final double amount) {
return amount * getFactorToMilliMeters();
}
public double fromMilliMeters(final double amount) {
return amount / getFactorToMilliMeters();
}
}
public static class UnitFormatter extends AbstractFormatter {
private static final Pattern PATTERN;
static {
//Building the Pattern is not too tricky. It just needs some attention.
final String blank = "\\p{Blank}"; //Match any whitespace character.
final String blankGroupAny = "(" + blank + "*)"; //Match any whitespace character, zero or more times and group them.
final String digits = "\\d"; //Match any digit.
final String digitsGroup = "(" + digits + "+)"; //Match any digit, at least once and group them.
final String digitsSuperGroup = "(\\-?" + digitsGroup + "\\.?" + digitsGroup + "?)"; //Matches for example "-2.4" or "2.4" or "2" or "-2" in the same group!
//Create the pattern part which matches any of the available units...
final Unit[] units = Unit.values();
final StringBuilder unitsBuilder = new StringBuilder(Pattern.quote("")); //Empty unit strings are valid (they default to millimeters).
for (int i = 0; i < units.length; ++i)
unitsBuilder.append('|').append(Pattern.quote(units[i].name()));
final String unitsGroup = "(" + unitsBuilder + ")";
final String full = "^" + blankGroupAny + digitsSuperGroup + blankGroupAny + unitsGroup + blankGroupAny + "$"; //Compose full pattern.
PATTERN = Pattern.compile(full);
}
private Unit lastUnit = Unit.MM;
@Override
public Object stringToValue(final String text) throws ParseException {
if (text == null || text.trim().isEmpty())
throw new ParseException("Null or empty text.", 0);
try {
final Matcher matcher = PATTERN.matcher(text.toUpperCase());
if (!matcher.matches())
throw new ParseException("Invalid input.", 0);
final String amountStr = matcher.group(2),
unitStr = matcher.group(6);
final double amount = Double.parseDouble(amountStr);
lastUnit = unitStr.trim().isEmpty()? null: Unit.valueOf(unitStr);
return lastUnit == null? amount: lastUnit.toMilliMeters(amount);
}
catch (final IllegalArgumentException iax) {
throw new ParseException("Failed to parse input \"" + text + "\".", 0);
}
}
@Override
public String valueToString(final Object value) throws ParseException {
final double amount = lastUnit == null? (Double) value: lastUnit.fromMilliMeters((Double) value);
return String.format("%.4f", amount).replace(',', '.') + ((lastUnit == null)? "": (" " + lastUnit.name()));
}
}
public static class UnitFormatterFactory extends AbstractFormatterFactory {
@Override
public AbstractFormatter getFormatter(final JFormattedTextField tf) {
if (!(tf.getFormatter() instanceof UnitFormatter))
return new UnitFormatter();
return tf.getFormatter();
}
}
public static void main(final String[] args) {
final JSpinner spin = new JSpinner(new SpinnerNumberModel(0d, -1000000d, 1000000d, 1d)); //Default numbers in millimeters.
((DefaultEditor) spin.getEditor()).getTextField().setFormatterFactory(new UnitFormatterFactory());
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);
}
}
我使用了测量长度的单位（毫米、英寸、英尺和码）。但是您可以根据自己的需要进行调整。
注意在上面的实现中SpinnerNumberModel只知道毫米。AbstractFormatter将毫米转换为单位并返回的句柄（根据用户的输入）。这意味着当您将单位设置为YD（即码）时，模型仍会以毫米旋转，但JFormattedTextField会以码的分数旋转。试试看你自己我的意思。这意味着/将始终返回毫米getValue()的数量，无论文本字段中的单位是什么（将始终进行转换）。JSpinnerSpinnerNumberModelAbstractFormatter
作为第二种情况，如果需要，可以将转换移到AbstractFormatter. 例如，您可以让用户在微调器中输入一个始终独立于测量单位的值。这样，用户总是看到值以步长等于 1 旋转（在本例中），同时AbstractFormatter将保留用户设置为微调器的最后一个单位的属性。因此，现在当您从JSpinner/获取值时，SpinnerNumberModel您将获得一个独立于单位的数字，然后使用设置为的最后一个单位AbstractFormatter来确定用户的意思单位。这是使用微调器的有点不同并且可能更方便的方式。
这是第二种情况的代码：
import java.text.ParseException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
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 StepMain {
public static enum Unit {
MM, //Milimeters.
IN, //Inches (1 inch == 25.4 mm).
FT, //Feet (1 foot == 12 inches).
YD; //Yards (1 yard == 3 feet).
}
public static class UnitFormatter extends AbstractFormatter {
private static final Pattern PATTERN;
static {
//Building the Pattern is not too tricky. It just needs some attention.
final String blank = "\\p{Blank}"; //Match any whitespace character.
final String blankGroupAny = "(" + blank + "*)"; //Match any whitespace character, zero or more times and group them.
final String digits = "\\d"; //Match any digit.
final String digitsGroup = "(" + digits + "+)"; //Match any digit, at least once and group them.
final String digitsSuperGroup = "(\\-?" + digitsGroup + "\\.?" + digitsGroup + "?)"; //Matches for example "-2.4" or "2.4" or "2" or "-2" in the same group!
//Create the pattern part which matches any of the available units...
final Unit[] units = Unit.values();
final StringBuilder unitsBuilder = new StringBuilder(Pattern.quote("")); //Empty unit strings are valid (they default to milimeters).
for (int i = 0; i < units.length; ++i)
unitsBuilder.append('|').append(Pattern.quote(units[i].name()));
final String unitsGroup = "(" + unitsBuilder + ")";
final String full = "^" + blankGroupAny + digitsSuperGroup + blankGroupAny + unitsGroup + blankGroupAny + "$"; //Compose full pattern.
PATTERN = Pattern.compile(full);
}
private Unit lastUnit = Unit.MM;
@Override
public Object stringToValue(final String text) throws ParseException {
if (text == null || text.trim().isEmpty())
throw new ParseException("Null or empty text.", 0);
try {
final Matcher matcher = PATTERN.matcher(text.toUpperCase());
if (!matcher.matches())
throw new ParseException("Invalid input.", 0);
final String amountStr = matcher.group(2),
unitStr = matcher.group(6);
final double amount = Double.parseDouble(amountStr);
lastUnit = Unit.valueOf(unitStr);
return amount;
}
catch (final IllegalArgumentException iax) {
throw new ParseException("Failed to parse input \"" + text + "\".", 0);
}
}
@Override
public String valueToString(final Object value) throws ParseException {
return String.format("%.3f", value).replace(',', '.') + ' ' + lastUnit.name();
}
}
public static class UnitFormatterFactory extends AbstractFormatterFactory {
@Override
public AbstractFormatter getFormatter(final JFormattedTextField tf) {
if (!(tf.getFormatter() instanceof UnitFormatter))
return new UnitFormatter();
return tf.getFormatter();
}
}
public static void main(final String[] args) {
final JSpinner spin = new JSpinner(new SpinnerNumberModel(0d, -1000000d, 1000000d, 0.001d));
((DefaultEditor) spin.getEditor()).getTextField().setFormatterFactory(new UnitFormatterFactory());
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);
}
}
至于您所说的语言环境，如果我理解正确，您希望逗号和点都在同一个微调器中运行吗？如果是这样，您可以在此处查看答案。在这种情况下，问题再次通过使用自定义AbstractFormatter.