001/* -*- mode: Java; c-basic-offset: 2; indent-tabs-mode: nil; coding: utf-8-unix -*-
002 *
003 * Copyright © 2017 MicroBean.
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
014 * implied.  See the License for the specific language governing
015 * permissions and limitations under the License.
016 */
017package org.microbean.configuration.spi;
018
019import java.io.Serializable; // for javadoc only
020
021import org.microbean.configuration.api.TypeLiteral;
022
023/**
024 * A {@link TypeLiteral} that can convert {@link String} values into
025 * another kind of {@link Object}.
026 *
027 * @param <T> the type of {@link Object} to which {@link String}
028 * values may be converted
029 *
030 * @author <a href="https://about.me/lairdnelson"
031 * target="_parent">Laird Nelson</a>
032 *
033 * @see #convert(String)
034 */
035public abstract class Converter<T> extends TypeLiteral<T> {
036
037
038  /*
039   * Static fields.
040   */
041
042  
043  /**
044   * The version of this class for {@linkplain Serializable
045   * serialization purposes}.
046   */
047  private static final long serialVersionUID = 1L;
048
049
050  /*
051   * Constructors.
052   */
053  
054
055  /**
056   * Creates a new {@link Converter}.
057   */
058  protected Converter() {
059    super(Converter.class);
060  }
061
062
063  /*
064   * Instance methods.
065   */
066  
067
068  /**
069   * Converts the supplied {@code value} into an {@link Object} of the
070   * appropriate type.
071   *
072   * <p>Implementations of this method are permitted to return {@code
073   * null}.</p>
074   *
075   * @param value the value to convert; may be {@code null}
076   *
077   * @return the converted value, which may be {@code null}
078   */
079  public abstract T convert(final String value);
080
081}