如何针对多种模式验证输入日期？ [英] how to validate input date against multiple patterns?

问题描述

在我的jsf应用程序中，我知道如何使用jsf转换器对我的 ice中的一个模式验证用户输入：selectInputDate ：

In my jsf application I know how to validate user input against one pattern in my ice:selectInputDate using a jsf converter:

   <f:convertDateTime pattern="MM/dd/yyyy"  />

但如果我想让用户能够以格式输入日期，我该怎么办？ MM-dd-yyyy呢？

but how should I do if I want to let the user be able to enter a date in format: "MM-dd-yyyy" too?

我认为这可以从jsf扩展DateConverter但我已经尝试过了，但是我失败了。您是否有一个有效的示例来根据多种模式验证输入日期？

I think this can be done extending DateConverter from jsf but I already tried with that and I fail. Do you have a valid example to validate input date against multiple patterns?

谢谢。

UPDATE ：我正在使用jsf 1.2

UPDATE: I'm using jsf 1.2

推荐答案

创建一个接受多个的自定义转换器组件上的< f：attribute> 模式。

Create a custom converter which accepts multiple patterns by <f:attribute> on the component.

以下是您希望获得视图的方式看起来像：

Here's how you'd like to have the view to look like:

<h:inputText id="input" value="#{bean.date}">
    <f:converter converterId="multiDateConverter" />
    <f:attribute name="pattern1" value="MM/dd/yyyy" />
    <f:attribute name="pattern2" value="MM-dd-yyyy" />
</h:inputText>

以下是转换器的外观（对于JSF 1.x，将其注册为

And here's how the converter can look like (for JSF 1.x, register it as

<converter-id>multiDateConverter</converter-id>

在 faces-config.xml 代替）

@FacesConverter(value="multiDateConverter")
public class MultiDateConverter implements Converter {

    @Override
    public Object getAsObject(FacesContext context, UIComponent component, String value) throws ConverterException {
        List<String> patterns = getPatterns(component);
        Date date = null;

        for (String pattern : patterns) {
            SimpleDateFormat sdf = new SimpleDateFormat(pattern);
            sdf.setLenient(false); // Don't parse dates like 33-33-3333.

            try {
                date = sdf.parse(value);
                break;
            } catch (ParseException ignore) {
                //
            }
        }

        if (date == null) {
            throw new ConverterException(new FacesMessage("Invalid date format, must match either of " + patterns));
        }

        return date;
    }

    @Override
    public String getAsString(FacesContext context, UIComponent component, Object value) throws ConverterException {
        return new SimpleDateFormat(getPatterns(component).get(0)).format((Date) value);
    }

    private static List<String> getPatterns(UIComponent component) {
        List<String> patterns = new ArrayList<String>();

        for (int i = 1; i < Integer.MAX_VALUE; i++) {
            String pattern = (String) component.getAttributes().get("pattern" + i);

            if (pattern != null) {
                patterns.add(pattern);
            } else {
                break;
            }
        }

        if (patterns.isEmpty()) {
            throw new IllegalArgumentException("Please provide <f:attribute name=\"patternX\"> where X is the order number");
        }

        return patterns;
    }

}

请注意，它只选择第一个（默认）模式重新显示值。所以在上面的例子中，如果你输入 05-10-2011 ，那么它会被重新显示为 05/10/2011 。

Note that it only picks the first (default) pattern to redisplay the value. So in the above example, if you enter 05-10-2011, then it get redisplayed as 05/10/2011.

无关到具体问题，模式 MM -dd-yyyy 不常见。你的意思是不是要用 dd-MM-yyyy ？

Unrelated to the concrete problem, the pattern MM-dd-yyyy isn't very common. Didn't you mean to use dd-MM-yyyy?

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