001/* -*- mode: Java; c-basic-offset: 2; indent-tabs-mode: nil; coding: utf-8-unix -*-
002 *
003 * Copyright © 2020 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.settings.converter;
018
019import javax.enterprise.context.ApplicationScoped;
020import javax.enterprise.context.Dependent;
021
022import org.microbean.settings.Converter;
023import org.microbean.settings.Value;
024
025@Dependent
026public class ClassConverter<T> implements Converter<Class<T>> {
027
028  private static final long serialVersionUID = 1L;
029
030  public ClassConverter() {
031    super();
032  }
033
034  @Override
035  public Class<T> convert(final Value value) {
036    final Class<T> returnValue;
037    if (value == null) {
038      returnValue = null;
039    } else {
040      final String className = value.get();
041      if (className == null) {
042        returnValue = null;
043      } else {
044        Class<T> result = null;
045        try {
046          @SuppressWarnings("unchecked")
047          final Class<T> temp = (Class<T>)Class.forName(className, true, Thread.currentThread().getContextClassLoader());
048          result = temp;
049        } catch (final ClassNotFoundException classNotFoundException) {
050          throw new IllegalArgumentException(className, classNotFoundException);
051        } finally {
052          returnValue = result;
053        }
054      }
055    }
056    return returnValue;
057  }
058
059}