• Home
• org.codeprimate
• cp-elements
• 1.0.0.M5
• source code
• Converter.java

×

Project download

Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance.
Project price only 1 $

You can buy this project and download/modify it how often you want.

org.cp.elements.data.conversion.Converter Maven / Gradle / Ivy

/*
 * 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;

import static org.cp.elements.lang.ElementsExceptionsFactory.newConversionException;

import java.util.function.Function;

import org.cp.elements.lang.Assert;
import org.cp.elements.lang.ObjectUtils;
import org.cp.elements.lang.annotation.NullSafe;

/**
 * The {@link Converter} interface defines a contract for objects that convert an {@link Object}
 * from one {@link Class type} to another.
 *
 * @author John J. Blum
 * @param  {@link Class source type} to convert from.
 * @param  {@link Class target type} to convert to.
 * @see java.util.function.Function
 * @see org.cp.elements.data.conversion.AbstractConverter
 * @see org.cp.elements.data.conversion.ConversionService
 * @see org.cp.elements.data.conversion.ConversionServiceAware
 * @since 1.0.0
 */
public interface Converter extends ConversionServiceAware, Function {

  /**
   * Applies this {@link Converter} / {@link Function} to the given {@link S argument}.
   *
   * @param value {@link Object} on which to apply this {@link Converter} / {@link Function}.
   * @return the converted {@link T value} from applying this {@link Converter} /  {@link Function}
   * to the given {@link S value}.
   * @see java.util.function.Function#apply(Object)
   * @see #convert(Object)
   */
  @Override
  default T apply(S value) {
    return convert(value);
  }

  /**
   * Determines whether this {@link Converter} can convert the given {@link Object}
   * to the specified {@link Class type}.
   *
   * @param value {@link Object} to convert.
   * @param toType {@link Class type} to convert the {@link Object} to.
   * @return a boolean value indicating whether this {@link Converter}
   * can convert the given {@link Object} to the specified {@link Class type}.
   * @see org.cp.elements.data.conversion.ConversionService#canConvert(Object, Class)
   * @see #canConvert(Class, Class)
   */
  @NullSafe
  default boolean canConvert(Object value, Class toType) {
    return canConvert(ObjectUtils.getClass(value), toType);
  }

  /**
   * 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)
   */
  boolean canConvert(Class fromType, Class 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)
   */
  T convert(S value);

  /**
   * 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)
   */
  default  QT convert(S value, Class qualifyingType) {

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

    try {
      return qualifyingType.cast(convert(value));
    }
    catch (ClassCastException cause) {
      throw newConversionException(cause, "Cannot convert [%1$s] into an Object of type [%2$s]",
        value, qualifyingType.getName());
    }
  }
}