/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package com.sun.xml.internal.bind.v2.util;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.Reader;

import javax.activation.DataHandler;

import javax.activation.DataSource;

import javax.activation.MimeType;

import javax.activation.MimeTypeParseException;

import javax.xml.transform.Source;

import javax.xml.transform.stream.StreamSource;

/**

 * {@link Source} implementation backed by {@link DataHandler}.

 *

 * <p>

 * This implementation allows the same {@link Source} to be used

 * mutliple times.

 *

 * <p>

 * {@link Source} isn't really pluggable. As a consequence,

 * this implementation is clunky --- weak against unexpected

 * usage of the class.

 *

 * @author Kohsuke Kawaguchi

 */

public final class DataSourceSource extends StreamSource {

    private final DataSource source;

    /**

     * If null, default to the encoding declaration

     */

    private final String charset;

    // remember the value we returned so that the 2nd invocation

    // will return the same object, which is what's expeted out of

    // StreamSource

    private Reader r;

    private InputStream is;

    public DataSourceSource(DataHandler dh) throws MimeTypeParseException {

        this(dh.getDataSource());

    }

    public DataSourceSource(DataSource source) throws MimeTypeParseException {

        this.source = source;

        String ct = source.getContentType();

        if(ct==null) {

            charset = null;

        } else {

            MimeType mimeType = new MimeType(ct);

            this.charset = mimeType.getParameter("charset");

        }

    }

    @Override

    public void setReader(Reader reader) {

        throw new UnsupportedOperationException();

    }

    @Override

    public void setInputStream(InputStream inputStream) {

        throw new UnsupportedOperationException();

    }

    @Override

    public Reader getReader() {

        try {

            if(charset==null)   return null;

            if(r==null)

                r = new InputStreamReader(source.getInputStream(),charset);

            return r;

        } catch (IOException e) {

            // argh

            throw new RuntimeException(e);

        }

    }

    @Override

    public InputStream getInputStream() {

        try {

            if(charset!=null)   return null;

            if(is==null)

                is = source.getInputStream();

            return is;

        } catch (IOException e) {

            // argh

            throw new RuntimeException(e);

        }

    }

    public DataSource getDataSource() {

        return source;

    }

}