001package ball.activation;
002/*-
003 * ##########################################################################
004 * Utilities
005 * %%
006 * Copyright (C) 2008 - 2022 Allen D. Ball
007 * %%
008 * Licensed under the Apache License, Version 2.0 (the "License");
009 * you may not use this file except in compliance with the License.
010 * You may obtain a copy of the License at
011 *
012 *      http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing, software
015 * distributed under the License is distributed on an "AS IS" BASIS,
016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
017 * See the License for the specific language governing permissions and
018 * limitations under the License.
019 * ##########################################################################
020 */
021import java.beans.ConstructorProperties;
022import java.io.IOException;
023import java.io.InputStream;
024import java.io.OutputStream;
025import java.util.Objects;
026import javax.activation.DataSource;
027
028/**
029 * Abstract {@link DataSource} base class that wraps another
030 * {@link DataSource}.
031 *
032 * @author {@link.uri mailto:ball@hcf.dev Allen D. Ball}
033 */
034public abstract class FilterDataSource extends AbstractDataSource {
035    private final DataSource ds;
036
037    /**
038     * @param   ds              The filtered {@link DataSource}.
039     */
040    @ConstructorProperties({ "dataSource" })
041    protected FilterDataSource(DataSource ds) {
042        super();
043
044        this.ds = Objects.requireNonNull(ds);
045    }
046
047    /**
048     * Private no-argument constructor (for JAXB annotated subclasses).
049     */
050    private FilterDataSource() { this(new ByteArrayDataSource(null, null)); }
051
052    /**
053     * Method to get the filtered {@link DataSource}.
054     *
055     * @return  The filtered {@link DataSource}.
056     */
057    protected DataSource getDataSource() { return ds; }
058
059    @Override
060    public String getName() { return getDataSource().getName(); }
061
062    @Override
063    public void setName(String name) {
064        try {
065            DataSource ds = getDataSource();
066
067            ds.getClass()
068                .getMethod("setName", String.class)
069                .invoke(ds, name);
070        } catch (Exception exception) {
071            throw new UnsupportedOperationException(exception);
072        }
073    }
074
075    @Override
076    public String getContentType() { return getDataSource().getContentType(); }
077
078    @Override
079    public void setContentType(String type) {
080        try {
081            DataSource ds = getDataSource();
082
083            ds.getClass()
084                .getMethod("setContentType", String.class)
085                .invoke(ds, type);
086        } catch (Exception exception) {
087            throw new UnsupportedOperationException(exception);
088        }
089    }
090
091    @Override
092    public InputStream getInputStream() throws IOException {
093        return getDataSource().getInputStream();
094    }
095
096    @Override
097    public OutputStream getOutputStream() throws IOException {
098        return getDataSource().getOutputStream();
099    }
100}