DataSourceProvider.java

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 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *  
 *   http://www.apache.org/licenses/LICENSE-2.0
 *  
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 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
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package org.apache.wink.common.internal.providers.entity;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;

import javax.activation.DataSource;
import javax.ws.rs.Consumes;
import javax.ws.rs.Produces;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.MessageBodyReader;
import javax.ws.rs.ext.MessageBodyWriter;
import javax.ws.rs.ext.Provider;

@Provider
@Produces("*/*")
@Consumes("*/*")
public class DataSourceProvider implements MessageBodyReader<DataSource>,
    MessageBodyWriter<DataSource> {

    public boolean isReadable(Class<?> type,
                              Type genericType,
                              Annotation[] annotations,
                              MediaType mediaType) {
        return type.isAssignableFrom(DataSource.class);
    }

    public DataSource readFrom(Class<DataSource> type,
                               Type genericType,
                               Annotation[] annotations,
                               MediaType mediaType,
                               MultivaluedMap<String, String> httpHeaders,
                               InputStream entityStream) throws IOException,
        WebApplicationException {
        return new ByteArrayDataSource(entityStream, (mediaType == null) ? null : mediaType
            .toString());
    }

    public long getSize(DataSource t,
                        Class<?> type,
                        Type genericType,
                        Annotation[] annotations,
                        MediaType mediaType) {
        return -1;
    }

    public boolean isWriteable(Class<?> type,
                               Type genericType,
                               Annotation[] annotations,
                               MediaType mediaType) {
        return DataSource.class.isAssignableFrom(type);
    }

    public void writeTo(DataSource t,
                        Class<?> type,
                        Type genericType,
                        Annotation[] annotations,
                        MediaType mediaType,
                        MultivaluedMap<String, Object> httpHeaders,
                        OutputStream entityStream) throws IOException, WebApplicationException {
        InputStream inputStream = t.getInputStream();
        final byte[] data = new byte[2048];
        int read;
        while ((read = inputStream.read(data)) != -1) {
            entityStream.write(data, 0, read);
        }
        entityStream.flush();
    }

    public static class ByteArrayDataSource implements DataSource {

        private final String contentType;
        private final byte[] buffer;
        private final int    length;

        public ByteArrayDataSource(InputStream is, String contentType) throws IOException {
            DataStoreByteArrayOutputStream os = new DataStoreByteArrayOutputStream();
            byte[] buf = new byte[8192];
            int len;
            while ((len = is.read(buf)) > 0) {
                os.write(buf, 0, len);
            }

            this.buffer = os.getBuf();
            this.length = os.getCount();
            this.contentType = contentType;
        }

        public String getContentType() {
            return contentType;
        }

        public InputStream getInputStream() {
            return new ByteArrayInputStream(buffer, 0, length);
        }

        public String getName() {
            return null;
        }

        public OutputStream getOutputStream() {
            throw new UnsupportedOperationException();
        }

        static class DataStoreByteArrayOutputStream extends ByteArrayOutputStream {
            public byte[] getBuf() {
                return buf;
            }

            public int getCount() {
                return count;
            }
        }
    }
}