org.cp.elements.data.conversion.converters.IntegerConverter Maven / Gradle / Ivy
/*
* Copyright 2011-Present Author or Authors.
*
* 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 org.cp.elements.data.conversion.converters;
import static org.cp.elements.lang.ElementsExceptionsFactory.newConversionException;
import org.cp.elements.data.conversion.ConversionException;
import org.cp.elements.data.conversion.Converter;
import org.cp.elements.data.conversion.DefaultableConverter;
import org.cp.elements.lang.StringUtils;
import org.cp.elements.lang.annotation.NullSafe;
import org.cp.elements.lang.annotation.Nullable;
import org.cp.elements.lang.annotation.Order;
/**
* {@link IntegerConverter} converts an {@link Object} to an {@link Integer}.
*
* @author John J. Blum
* @see java.lang.Integer
* @see java.lang.Object
* @see java.lang.String
* @see org.cp.elements.data.conversion.DefaultableConverter
* @see org.cp.elements.lang.annotation.Order
* @since 1.0.0
*/
@SuppressWarnings("unused")
@Order(-1_000_000)
public class IntegerConverter extends DefaultableConverter {
/**
* Determines whether this {@link Converter} can convert {@link Object Objects}
* {@link Class from type} {@link Class to type}.
*
* @param fromType {@link Class type} to convert from.
* @param toType {@link Class type} to convert to.
* @return a boolean indicating whether this {@link Converter} can convert {@link Object Objects}
* {@link Class from type} {@link Class to type}.
* @see org.cp.elements.data.conversion.ConversionService#canConvert(Class, Class)
* @see #canConvert(Object, Class)
*/
@Override
public boolean canConvert(Class fromType, Class toType) {
return isAssignableTo(fromType, Number.class, String.class) && Integer.class.equals(toType);
}
/**
* Converts an {@link Object} of {@link Class type S} into an {@link Object} of {@link Class type T}.
*
* @param value {@link Object} of {@link Class type S} to convert.
* @return the converted {@link Object} of {@link Class type T}.
* @throws ConversionException if the {@link Object} cannot be converted.
* @see org.cp.elements.data.conversion.ConversionService#convert(Object, Class)
* @see #convert(Object, Class)
*/
@Override
public Integer convert(Object value) {
if (value instanceof Number) {
return ((Number) value).intValue();
}
else if (isStringWithDigits(value)) {
try {
return Integer.parseInt(value.toString().trim());
}
catch (NumberFormatException cause) {
throw newConversionException(cause, "[%s] is not a valid Integer", value);
}
}
else {
return super.convert(value);
}
}
@NullSafe
private boolean isStringWithDigits(@Nullable Object value) {
return value instanceof String && StringUtils.containsDigits(value.toString());
}
}