convert JSON Type to Byte array format in java

Question

I have a problem when I want to sending data using byte format in UDP protocol, the problem is when I try to create a data with type json object, I can\'t get the byte format of

Answer 1

To avoid unnecessary conversion from String to byte[] which enforces encoding based on the provided charset, I prefer to use JsonWriter directly with ByteArrayOutputStream for instance (JsonValue subtypes use JsonWriter with StringWriter):

ByteArrayOutputStream stream = new ByteArrayOutputStream();
Json.createWriter(stream).write(obj);

byte[] sendData = stream.toByteArray()

System.out.println("Bytes array: " + sendData);
System.out.println("As a string: " + stream.toString());

Additionally, one can even enable pretty printing as follows:

Json.createWriterFactory(
            Collections.singletonMap(JsonGenerator.PRETTY_PRINTING, true))
        .createWriter(stream)
        .write(obj);

The only sad thing is that it's not an one-liner. You'd need 3 at least (given the fact that you omit calling JsonWriter.close() which is unnecessary in this context).