org.cp.elements.data.conversion.converters.NumberConverter Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of cp-elements Show documentation

Java Simplified. Extensions and Useful Constructs for the Java Platform. Codeprimate Elements (a.k.a. cp-elements) is a Java library and micro-framework used to simplify the development of software applications written in Java. Elements packages several APIs into one library in order to address various application concerns and aspects of software design and development collectively and conveniently. Elements is a highly simple, yet robust and proven library built on solid OO principles, software design patterns and best practices to effectively solve common and reoccurring problems in software development.

There is a newer version: 2.0.0-M1

Show newest version

/*
 * Copyright 2016 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 java.math.BigDecimal;
import java.math.BigInteger;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;

import org.cp.elements.data.conversion.AbstractConverter;
import org.cp.elements.data.conversion.ConversionException;
import org.cp.elements.data.conversion.Converter;
import org.cp.elements.lang.Assert;
import org.cp.elements.lang.StringUtils;

/**
 * {@link NumberConverter} converts an {@link Object} to a {@link Number} of a {@link Class qualified numerical type}.
 *
 * @author John J. Blum
 * @see java.lang.Number
 * @see java.lang.Object
 * @see java.lang.String
 * @see java.math.BigDecimal
 * @see java.math.BigInteger
 * @see java.util.concurrent.atomic.AtomicInteger
 * @see java.util.concurrent.atomic.AtomicLong
 * @see org.cp.elements.data.conversion.AbstractConverter
 * @since 1.0.0
 */
@SuppressWarnings("unused")
public class NumberConverter extends AbstractConverter {

  protected static final String CONVERSION_EXCEPTION_MESSAGE =
    "[%1$s] is not a valid number of the qualifying type [%2$s]";

  protected  QT parseNumber(String number, Class numberType) {

    if (AtomicInteger.class.isAssignableFrom(numberType)) {
      return numberType.cast(new AtomicInteger(Integer.parseInt(number)));
    }
    else if (AtomicLong.class.isAssignableFrom(numberType)) {
      return numberType.cast(new AtomicLong(Long.parseLong(number)));
    }
    else if (BigDecimal.class.isAssignableFrom(numberType)) {
      return numberType.cast(new BigDecimal(number));
    }
    else if (BigInteger.class.isAssignableFrom(numberType)) {
      return numberType.cast(new BigInteger(number));
    }
    else if (Byte.class.isAssignableFrom(numberType)) {
      return numberType.cast(Byte.parseByte(number));
    }
    else if (Short.class.isAssignableFrom(numberType)) {
      return numberType.cast(Short.parseShort(number));
    }
    else if (Integer.class.isAssignableFrom(numberType)) {
      return numberType.cast(Integer.parseInt(number));
    }
    else if (Long.class.isAssignableFrom(numberType)) {
      return numberType.cast(Long.parseLong(number));
    }
    else if (Float.class.isAssignableFrom(numberType)) {
      return numberType.cast(Float.parseFloat(number));
    }
    else if (Double.class.isAssignableFrom(numberType)) {
      return numberType.cast(Double.parseDouble(number));
    }

    throw newConversionException("[%s] is not a valid Number type", numberType.getName());
  }

  protected  QT toQualifyingNumber(Number number, Class numberType) {

    if (AtomicInteger.class.isAssignableFrom(numberType)) {
      return numberType.cast(new AtomicInteger(number.intValue()));
    }
    else if (AtomicLong.class.isAssignableFrom(numberType)) {
      return numberType.cast(new AtomicLong(number.longValue()));
    }
    else if (BigDecimal.class.isAssignableFrom(numberType)) {
      return numberType.cast(new BigDecimal(number.doubleValue()));
    }
    else if (BigInteger.class.isAssignableFrom(numberType)) {
      return numberType.cast(new BigInteger(number.toString()));
    }
    else if (Byte.class.isAssignableFrom(numberType)) {
      return numberType.cast(number.byteValue());
    }
    else if (Short.class.isAssignableFrom(numberType)) {
      return numberType.cast(number.shortValue());
    }
    else if (Integer.class.isAssignableFrom(numberType)) {
      return numberType.cast(number.intValue());
    }
    else if (Long.class.isAssignableFrom(numberType)) {
      return numberType.cast(number.longValue());
    }
    else if (Float.class.isAssignableFrom(numberType)) {
      return numberType.cast(number.floatValue());
    }
    else if (Double.class.isAssignableFrom(numberType)) {
      return numberType.cast(number.doubleValue());
    }

    throw newConversionException("[%s] is not a valid Number type", numberType.getName());
  }

  /**
   * 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 fromType != null && isAssignableTo(fromType, Number.class, String.class)
      && toType != null && Number.class.isAssignableFrom(toType);
  }

  /**
   * Converts an {@link Object} of {@link Class type S} into an {@link Object} of {@link Class qualifying type QT}.
   *
   * @param  {@link Class qualifying type} extending {@link Class type T}.
   * @param value {@link Object} of {@link Class type S} to convert.
   * @param qualifyingType the {@link Class qualifying type} of the {@link Object} resolved in the conversion.
   * @return the converted {@link Object} of {@link Class qualifying type QT}.
   * @throws ConversionException if the {@link Object} cannot be converted.
   * @throws IllegalArgumentException if {@link Class qualifying type} is {@literal null}.
   * @see org.cp.elements.data.conversion.ConversionService#convert(Object, Class)
   * @see #convert(Object)
   */
  @Override
  public  QT convert(Object value, Class qualifyingType) {

    Assert.notNull(qualifyingType, "Qualifying type is required");

    try {
      if (qualifyingType.isInstance(value)) {
        return qualifyingType.cast(value);
      }
      else if (value instanceof Number) {
        return toQualifyingNumber((Number) value, qualifyingType);
      }
      else if (value instanceof String && StringUtils.containsDigits(value.toString().trim())) {
        return parseNumber(value.toString().trim(), qualifyingType);
      }
      else {
        throw newConversionException(CONVERSION_EXCEPTION_MESSAGE, value, qualifyingType.getName());
      }
    }
    catch (Exception cause) {

      if (cause instanceof ConversionException) {
        throw (ConversionException) cause;
      }

      throw newConversionException(cause, CONVERSION_EXCEPTION_MESSAGE, value, qualifyingType.getName());
    }
  }
}