Reading fields from bytearray - tcp

Question

I am trying to send a message via tcp. Unfortunately that does not work and hence I have created the following code for test purposes:
public void sendQuestion(String text) {
// Set timestamp.
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
TimeZone tz = TimeZone.getTimeZone("GMT+01:00");
df.setTimeZone(tz);
String date = df.format(new Date());
byte[] dateStr = date.getBytes();
// Set payload.
String payloadTemp = date + text;
byte[] payload = payloadTemp.getBytes();
// Send the payload.
clientOutputThread.send(1, payload);
....
}
public void send(byte type, byte[] payload) {
// Calculate and set size of message.
ByteBuffer bufferTemp = ByteBuffer.allocate(4);
bufferTemp.order(ByteOrder.BIG_ENDIAN);
byte[] payloadSize = bufferTemp.putInt(payload.length).array();
byte[] buffer = new byte[5 + payload.length];
System.arraycopy(payloadSize, 0, buffer, 0, 4);
System.arraycopy(payload, 0, buffer, 5, payload.length);
// Set message type.
buffer[4] = type;
// TEST: Try reading values again
ByteBuffer bb = ByteBuffer.wrap(buffer);
// get all the fields:
int payload2 = bb.getInt(0); // bytes 0-3
// byte 4 is the type
byte[] tmp = new byte[19]; // date is 19 bytes
bb.position(5);
bb.get(tmp);
String timestamp = tmp.toString();
byte[] tmp2 = new byte[payload2-19];
bb.get(tmp2); // text
String text = tmp2.toString();
....
}
Unfortunately, what I read as timestamp and text is rubbish, something of the sort of "[B#44f39650". Why? Am I reading wrong?
Thank you!

Answer 1

"[B#44f39650" is the result of calling toString() on an object which is a byte array. Which you are doing here:
String timestamp = tmp.toString();
So don't do that. Convert the byte array to a String, if you must do that at all, using the String constructors provided for the purposes.
However you should really be using the API of DataOutputStream and DataInputStream for this purpose.