Helper ChunkedOutput

Jan Burse, created Jan 14. 2019
package matula.util.misc;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
/**
* <p>Provides a chunked output.</p>
* <p/>
* Warranty & Liability
* To the extent permitted by applicable law and unless explicitly
* otherwise agreed upon, XLOG Technologies GmbH makes no warranties
* regarding the provided information. XLOG Technologies GmbH assumes
* no liability that any problems might be solved with the information
* provided by XLOG Technologies GmbH.
* <p/>
* Rights & License
* All industrial property rights regarding the information - copyright
* and patent rights in particular - are the sole property of XLOG
* Technologies GmbH. If the company was not the originator of some
* excerpts, XLOG Technologies GmbH has at least obtained the right to
* reproduce, change and translate the information.
* <p/>
* Reproduction is restricted to the whole unaltered document. Reproduction
* of the information is only allowed for non-commercial uses. Selling,
* giving away or letting of the execution of the library is prohibited.
* The library can be distributed as part of your applications and libraries
* for execution provided this comment remains unchanged.
* <p/>
* Restrictions
* Only to be distributed with programs that add significant and primary
* functionality to the library. Not to be distributed with additional
* software intended to replace any components of the library.
* <p/>
* Trademarks
* Jekejeke is a registered trademark of XLOG Technologies GmbH.
*/
final class ChunkedOutput extends FilterOutputStream {
private static final int CHUNK_SIZE = 1024;
private int count;
private byte[] buf = new byte[CHUNK_SIZE];
/**
* <p>Create a chunked output.</p>
*
* @param out The output stream.
*/
ChunkedOutput(OutputStream out) {
super(out);
}
/**
* <p>Write a byte to the chunked output.</p>
*
* @param b The byte.
* @throws IOException I/O Error.
*/
public void write(int b) throws IOException {
buf[count++] = (byte) b;
if (count >= buf.length)
writeChunk();
}
/**
* <p>Write bytes to the chunked output.</p>
*
* @param b The bytes.
* @param off The offset.
* @param len The length.
* @throws IOException I/O Error.
*/
public void write(byte[] b, int off, int len) throws IOException {
int fill = Math.min(buf.length - count, len);
while (fill != 0) {
System.arraycopy(b, off, buf, count, fill);
count += fill;
if (count >= buf.length)
writeChunk();
off += fill;
len -= fill;
fill = Math.min(buf.length - count, len);
}
}
/**
* <p>Flush the chunked output.</p>
*
* @throws IOException I/O Error.
*/
public void flush() throws IOException {
if (count > 0)
writeChunk();
out.flush();
}
/**
* <p>Flush the chunked output.</p>
*
* @throws IOException I/O Error.
*/
public void close() throws IOException {
flush();
writeChunk();
out.close();
}
/***************************************************************/
/* Chunk Utility */
/***************************************************************/
/**
* <p>Write a chunk to the underlying output.</p>
*
* @throws IOException I/O Error.
*/
private void writeChunk() throws IOException {
try {
byte[] countbytes = Integer.toHexString(count).getBytes("US-ASCII");
out.write(countbytes);
out.write('\r');
out.write('\n');
out.write(buf, 0, count);
out.write('\r');
out.write('\n');
count = 0;
} catch (UnsupportedEncodingException x) {
throw new RuntimeException("shouldn't happen");
}
}
}

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