src/java.xml.ws/share/classes/com/sun/xml/internal/ws/encoding/MIMEPartStreamingDataHandler.java

/*
 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
 * 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.ws.encoding;

import com.sun.xml.internal.org.jvnet.mimepull.MIMEPart;

import javax.activation.DataSource;
import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.File;

import com.sun.xml.internal.ws.developer.StreamingDataHandler;

/**
 * Implementation of {@link StreamingDataHandler} to access MIME
 * attachments efficiently. Applications can use the additional methods and decide
 * on how to access the attachment data in JAX-WS applications.
 *
 * <p>
 * for e.g.:
 *
 * DataHandler dh = proxy.getData();
 * StreamingDataHandler sdh = (StreamingDataHandler)dh;
 * // readOnce() doesn't store attachment on the disk in some cases
 * // for e.g when only one huge attachment after soap envelope part in MIME message
 * InputStream in = sdh.readOnce();
 * ...
 * in.close();
 * sdh.close();
 *
 * @author Jitendra Kotamraju
 */
public class MIMEPartStreamingDataHandler extends StreamingDataHandler {
    private final StreamingDataSource ds;

    public MIMEPartStreamingDataHandler(MIMEPart part) {
        super(new StreamingDataSource(part));
        ds = (StreamingDataSource)getDataSource();
    }

    @Override
    public InputStream readOnce() throws IOException {
        return ds.readOnce();
    }

    @Override
    public void moveTo(File file) throws IOException {
        ds.moveTo(file);
    }

    @Override
    public void close() throws IOException {
        ds.close();
    }

    private static final class StreamingDataSource implements DataSource {
        private final MIMEPart part;

        StreamingDataSource(MIMEPart part) {
            this.part = part;
        }

        @Override
        public InputStream getInputStream() throws IOException {
            return part.read();             //readOnce() ??
        }

        InputStream readOnce() throws IOException {
            try {
                return part.readOnce();
            } catch(Exception e) {
                throw new MyIOException(e);
            }
        }

        void moveTo(File file) throws IOException {
            part.moveTo(file);
        }

        @Override
        public OutputStream getOutputStream() throws IOException {
            return null;
        }

        @Override
        public String getContentType() {
            return part.getContentType();
        }

        @Override
        public String getName() {
            return "";
        }

        public void close() throws IOException {
            part.close();
        }
    }

    private static final class MyIOException extends IOException {
        private final Exception linkedException;

        MyIOException(Exception linkedException) {
            this.linkedException = linkedException;
        }

        @Override
        public Throwable getCause() {
            return linkedException;
        }
    }

}