AnnotationHelper.java

package play.data.binding;

import java.lang.annotation.Annotation;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

import org.apache.commons.lang.StringUtils;

import play.i18n.Lang;
import play.libs.I18N;

public class AnnotationHelper {

    /**
     * It can be something like As(lang={"fr,de","*"}, value={"dd-MM-yyyy","MM-dd-yyyy"})
     *
     * @param annotations
     * @param value
     * @return null if it cannot be converted because there is no annotation.
     * @throws ParseException
     *
     */
    public static Date getDateAs(Annotation[] annotations, String value) throws ParseException {
        // Look up for the BindAs annotation
        if (annotations == null) {
            return null;
        }
        for (Annotation annotation : annotations) {
            if (annotation.annotationType().equals(As.class)) {
                As as = (As) annotation;
                Locale locale = Lang.getLocale();
                String format = as.value()[0];
                if (!StringUtils.isEmpty(format)) {
                    // This can be comma separated
                    Tuple tuple = getLocale(as.lang());
                    if (tuple != null) {
                        // Avoid NPE and get the last value if not specified
                        format = as.value()[tuple.index < as.value().length ? tuple.index : as.value().length - 1];
                        locale = tuple.locale;
                    }
                }
                if (StringUtils.isEmpty(format)) {
                    format = I18N.getDateFormat();
                }
                SimpleDateFormat sdf = new SimpleDateFormat(format, locale);
                sdf.setLenient(false);
                return sdf.parse(value);

            }
        }
        return null;
    }

    public static Tuple getLocale(String[] langs) {
        int i = 0;
        for (String l : langs) {
            String[] commaSeparatedLang = l.split(",");
            for (String lang : commaSeparatedLang) {
                if (Lang.get().equals(lang) || "*".equals(lang)) {
                    Locale locale = null;
                    if ("*".equals(lang)) {
                        locale = Lang.getLocale();
                    }
                    if (locale == null) {
                        locale = Lang.getLocale(lang);
                    }
                    if (locale != null) {
                        return new Tuple(i, locale);
                    }
                }
            }
            i++;
        }
        return null;
    }

    /**
     * Contains the index of the locale inside the @As
     */
    private static class Tuple {
        
        public int index = -1;
        public Locale locale;

        public Tuple(int index, Locale locale) {
            this.locale = locale;
            this.index = index;
        }
    }
}