001/*
002 * Portions of this software was developed by employees of the National Institute
003 * of Standards and Technology (NIST), an agency of the Federal Government and is
004 * being made available as a public service. Pursuant to title 17 United States
005 * Code Section 105, works of NIST employees are not subject to copyright
006 * protection in the United States. This software may be subject to foreign
007 * copyright. Permission in the United States and in foreign countries, to the
008 * extent that NIST may hold copyright, to use, copy, modify, create derivative
009 * works, and distribute this software and its documentation without fee is hereby
010 * granted on a non-exclusive basis, provided that this notice and disclaimer
011 * of warranty appears in all copies.
012 *
013 * THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND, EITHER
014 * EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY
015 * THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF
016 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND FREEDOM FROM
017 * INFRINGEMENT, AND ANY WARRANTY THAT THE DOCUMENTATION WILL CONFORM TO THE
018 * SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE.  IN NO EVENT
019 * SHALL NIST BE LIABLE FOR ANY DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT,
020 * INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM,
021 * OR IN ANY WAY CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY,
022 * CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY PERSONS OR
023 * PROPERTY OR OTHERWISE, AND WHETHER OR NOT LOSS WAS SUSTAINED FROM, OR AROSE OUT
024 * OF THE RESULTS OF, OR USE OF, THE SOFTWARE OR SERVICES PROVIDED HEREUNDER.
025 */
026
027package gov.nist.secauto.metaschema.core.datatype;
028
029import gov.nist.secauto.metaschema.core.datatype.adapter.MetaschemaDataTypeProvider;
030
031import java.util.Collections;
032import java.util.LinkedList;
033import java.util.List;
034
035import edu.umd.cs.findbugs.annotations.NonNull;
036
037/**
038 * A base implementation of an {@link IDataTypeProvider}, supporting dynamic
039 * loading of Metaschema data type extensions at runtime.
040 * <p>
041 * The {@link MetaschemaDataTypeProvider} class provides an example of how to
042 * use this class to provide new data types.
043 */
044public abstract class AbstractDataTypeProvider implements IDataTypeProvider {
045  private final List<IDataTypeAdapter<?>> library = new LinkedList<>();
046
047  @SuppressWarnings("null")
048  @Override
049  public List<? extends IDataTypeAdapter<?>> getJavaTypeAdapters() {
050    synchronized (this) {
051      return Collections.unmodifiableList(library);
052    }
053  }
054
055  /**
056   * Register the provided {@code adapter} with the type system.
057   *
058   * @param adapter
059   *          the adapter to register
060   * @throws IllegalArgumentException
061   *           if another type adapter has no name
062   */
063  protected void registerDatatype(@NonNull IDataTypeAdapter<?> adapter) {
064    if (adapter.getNames().size() == 0) {
065      throw new IllegalArgumentException("The adapter has no name: " + adapter.getClass().getName());
066    }
067    synchronized (this) {
068      library.add(adapter);
069    }
070  }
071}