/*
* Copyright (c) 2015-2015 Amedia Utvikling AS.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package no.api.freemarker.java8.time;
import freemarker.core.Environment;
import freemarker.template.SimpleScalar;
import freemarker.template.TemplateModelException;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.time.zone.ZoneRulesException;
import java.util.List;
import java.util.Locale;
import java.util.Optional;
/**
* Helper methods and constants in use by the adapters.
*/
public final class DateTimeTools {
public static final String METHOD_EQUALS = "isEqual";
public static final String METHOD_BEFORE = "isBefore";
public static final String METHOD_AFTER = "isAfter";
public static final String METHOD_FORMAT = "format";
public static final String METHOD_DAYS = "days";
public static final String METHOD_MONTHS = "months";
public static final String METHOD_YEARS = "years";
public static final String METHOD_NANO = "nano";
public static final String METHOD_SECONDS = "seconds";
public static final String METHOD_UNKNOWN_MSG = "Unknown method call: ";
public static final String ILLEGAL_ZONE_ID_MSG = "Illegal Zone ID";
private DateTimeTools() {
throw new UnsupportedOperationException();
}
/**
* Create a DateTimeFormatter from a pattern found in a List on a given index.
*
* @param list A list of Strings containing the pattern
* @param index The index on where in the list the pattern is located.
* @param defaultFormatter A default formatter to be returned if the given list size is lower than the given index.
* @return A DateTimeFormatter for the given pattern, or the default formatter.
*/
public static DateTimeFormatter createDateTimeFormatter(final List list, final int index,
final DateTimeFormatter defaultFormatter) {
if (list.size() > 0) {
final String format = ((SimpleScalar) list.get(index)).getAsString();
final ExtFormatStyle style = DateTimeTools.getFormatStyle(format);
if (style != null) {
return style.getFormatter().withLocale(DateTimeTools.getLocale());
}
final Optional<DateTimeFormatter> builtin = DateTimeTools.getJreBuiltinFormatter(format);
return builtin.orElseGet(() -> DateTimeFormatter.ofPattern(format, DateTimeTools.getLocale()));
}
return defaultFormatter.withLocale(DateTimeTools.getLocale());
}
/**
* Create a DateTimeFormatter from a pattern found in a List on a given index.
*
* @param list A list of Strings containing the pattern
* @param index The index on where in the list the pattern is located.
* @param defaultPattern The pattern to be used for the formatter if the list size is lower than the given index.
* @return A DateTimeFormatter for the given pattern, or the default pattern.
*/
public static DateTimeFormatter createDateTimeFormatter(List list,
int index,
final String defaultPattern) {
return DateTimeFormatter.ofPattern(
list.size() > index
? ((SimpleScalar) list.get(index)).getAsString()
: defaultPattern, getLocale());
}
/**
* Look up a ZoneId based on a String in a list on a given index.
*
* @param list A list of Strings containing the String representation of the ZoneId.
* @param index The index on where in the list the ZoneId string is located.
* @return A ZoneId instance for the given ZoneId string. If index is lower than the list size, then an empty {@link Optional} will be returned.
* @throws TemplateModelException If Illegal ZoneId string was found in the list.
*/
public static Optional<ZoneId> zoneIdLookup(final List list, final int index) throws TemplateModelException {
if (list.size() > index) {
final String zoneIdString = ((SimpleScalar) list.get(index)).getAsString();
try {
return Optional.of(ZoneId.of(zoneIdString));
} catch (final ZoneRulesException e) {
throw new TemplateModelException(DateTimeTools.ILLEGAL_ZONE_ID_MSG, e);
}
}
return Optional.empty();
}
private static Locale getLocale() {
if (Environment.getCurrentEnvironment() != null) {
return Environment.getCurrentEnvironment().getLocale();
} else {
return Locale.getDefault();
}
}
private static ExtFormatStyle getFormatStyle(final String format) {
try {
return PreparedFormatStyle.valueOf(format);
} catch (IllegalArgumentException | NullPointerException ex) {
return null;
}
}
private static Optional<DateTimeFormatter> getJreBuiltinFormatter(final String name) {
try {
final Field dateTimeFormatterField = DateTimeFormatter.class.getField(name);
if ((dateTimeFormatterField.getModifiers() & Modifier.STATIC) != 0 // Check if field is static
&& DateTimeFormatter.class.isAssignableFrom(dateTimeFormatterField.getType())) {
return Optional.ofNullable((DateTimeFormatter) dateTimeFormatterField.get(null));
}
// Not static, or not of the correct type
return Optional.empty();
} catch (final NoSuchFieldException e) {
// Seems like name is no built in DateTimeFormatter
return Optional.empty();
} catch (final IllegalArgumentException e) {
// As this field is checked to be static, this should never occur
throw new RuntimeException("Field \"" + name + "\" has modifier STATIC but seems to be not static!", e);
} catch (final IllegalAccessException e) {
// Well, if you use a SecurityManager, we cannot do this
throw new RuntimeException(
"Not allowed to access Field \"" + name + "\" of class " + DateTimeFormatter.class, e);
}
}
}
