DateConverter.java
package dev.orne.beans.converters;
/*-
* #%L
* Orne Beans
* %%
* Copyright (C) 2020 Orne Developments
* %%
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Lesser Public License for more details.
*
* You should have received a copy of the GNU General Lesser Public
* License along with this program. If not, see
* <http://www.gnu.org/licenses/lgpl-3.0.html>.
* #L%
*/
import java.time.Instant;
import java.util.Date;
import javax.validation.constraints.NotNull;
import org.apache.commons.beanutils.Converter;
import org.apache.commons.beanutils.converters.AbstractConverter;
import org.apiguardian.api.API;
import org.apiguardian.api.API.Status;
/**
* Implementation of {@code Converter} that converts {@code Date} instances
* to and from {@code String} using delegating in a instance of
* {@code InstantConverter}.
*
* @author <a href="mailto:wamphiry@orne.dev">(w) Iker Hernaez</a>
* @version 1.0, 2020-08
* @since 0.3
*/
@API(status=Status.STABLE, since="0.3")
public class DateConverter
extends AbstractConverter {
/** The converter to use when converting {@code Instant} instances. */
private final @NotNull Converter instantConverter;
/**
* Creates a new instance that throws a {@code ConversionException} if an
* error occurs.
*/
public DateConverter() {
super();
this.instantConverter = new InstantConverter();
}
/**
* Creates a new instance that returns a default value if an error occurs.
*
* @param defaultValue The default value to be returned if the value to be
* converted is missing or an error occurs converting the value
*/
public DateConverter(final Date defaultValue) {
super(defaultValue);
this.instantConverter = new InstantConverter(
defaultValue == null ? null : defaultValue.toInstant());
}
/**
* Creates a new instance that throws a {@code ConversionException} if an
* error occurs.
*
* @param instantConverter The converter to use when converting
* {@code Instant} instances
*/
public DateConverter(
final @NotNull Converter instantConverter) {
super();
this.instantConverter = instantConverter;
}
/**
* Creates a new instance that returns a default value if an error occurs.
*
* @param instantConverter The converter to use when converting
* {@code Instant} instances
* @param defaultValue The default value to be returned if the value to be
* converted is missing or an error occurs converting the value
*/
public DateConverter(
final @NotNull Converter instantConverter,
final Date defaultValue) {
super(defaultValue);
this.instantConverter = instantConverter;
}
/**
* Returns the converter to use when converting {@code Instant} instances.
*
* @return The converter to use when converting {@code Instant} instances
*/
protected @NotNull Converter getInstantConverter() {
return this.instantConverter;
}
/**
* {@inheritDoc}
*/
@Override
protected @NotNull Class<Date> getDefaultType() {
return Date.class;
}
/**
* {@inheritDoc}
*/
@Override
protected <T> T convertToType(
final @NotNull Class<T> type,
final Object value)
throws Throwable {
if (type.isAssignableFrom(Date.class)) {
final Instant instant = this.instantConverter.convert(Instant.class, value);
if (instant == null) {
return null;
} else {
return type.cast(Date.from(instant));
}
}
throw conversionException(type, value);
}
/**
* {@inheritDoc}
*/
@Override
protected String convertToString(
final Object value)
throws Throwable {
if (value instanceof Date) {
return this.instantConverter.convert(String.class, ((Date) value).toInstant());
} else if (value instanceof String) {
return value.toString();
} else {
throw conversionException(String.class, value);
}
}
}