org.apache.juneau.rest.helper.StreamResource Maven / Gradle / Ivy
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// * *
// * http://www.apache.org/licenses/LICENSE-2.0 *
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package org.apache.juneau.rest.helper;
import static org.apache.juneau.internal.CollectionUtils.*;
import static org.apache.juneau.internal.IOUtils.*;
import java.io.*;
import java.util.*;
import org.apache.juneau.*;
import org.apache.juneau.http.*;
import org.apache.juneau.http.annotation.*;
/**
* Represents the contents of a byte stream file with convenience methods for adding HTTP response headers.
*
*
*
These objects can to be returned as responses by REST methods.
*
*
* StreamResources are meant to be thread-safe and reusable objects.
*
The contents of the request passed into the constructor are immediately converted to read-only byte arrays.
*
*
* Instances of this class can be built using {@link StreamResourceBuilder}.
*
*
See Also:
*
* - {@doc juneau-rest-server.RestMethod.StreamResource}
*
*/
@Response
public class StreamResource implements Streamable {
private final MediaType mediaType;
private final byte[][] contents;
private final Map headers;
/**
* Creates a new instance of a {@link StreamResourceBuilder}
*
* @return A new instance of a {@link StreamResourceBuilder}
*/
public static StreamResourceBuilder create() {
return new StreamResourceBuilder();
}
/**
* Constructor.
*
* @param mediaType The resource media type.
* @param headers The HTTP response headers for this streamed resource.
* @param contents
* The resource contents.
*
If multiple contents are specified, the results will be concatenated.
*
Contents can be any of the following:
*
* byte []InputStream
* Reader - Converted to UTF-8 bytes.
* File
* CharSequence - Converted to UTF-8 bytes.
*
* @throws IOException
*/
public StreamResource(MediaType mediaType, Map headers, Object...contents) throws IOException {
this.mediaType = mediaType;
this.headers = immutableMap(headers);
this.contents = new byte[contents.length][];
for (int i = 0; i < contents.length; i++) {
Object c = contents[i];
if (c == null)
this.contents[i] = new byte[0];
else if (c instanceof byte[])
this.contents[i] = (byte[])c;
else if (c instanceof InputStream)
this.contents[i] = readBytes((InputStream)c, 1024);
else if (c instanceof File)
this.contents[i] = readBytes((File)c);
else if (c instanceof Reader)
this.contents[i] = read((Reader)c).getBytes(UTF8);
else if (c instanceof CharSequence)
this.contents[i] = ((CharSequence)c).toString().getBytes(UTF8);
else
throw new IOException("Invalid class type passed to StreamResource: " + c.getClass().getName());
}
}
/**
* Get the HTTP response headers.
*
* @return
* The HTTP response headers.
*
An unmodifiable map.
*
Never null .
*/
@ResponseHeader("*")
public Map getHeaders() {
return headers;
}
@ResponseBody
@Override /* Streamable */
public void streamTo(OutputStream os) throws IOException {
for (byte[] b : contents)
os.write(b);
os.flush();
}
@ResponseHeader("Content-Type")
@Override /* Streamable */
public MediaType getMediaType() {
return mediaType;
}
}