1. byte[] -> InputStream
byte[] b = xxx;
InputStream is = new ByteArrayInputStream(b);
2. InputStream -> byte[]
InputStream is = xxx;
ByteArrayOutputStream bytestream = new ByteArrayOutputStream();
int ch;
while ((ch = is.read()) != -1) {
bytestream.write(ch);
}
byte[] b = bytestream.toByteArray();
bytestream.close();