Nxing

A server that just provides the qr- and barcode decoding of zxing over http(s) using netty.

Configuration

Configuration can be achived using the config.json. The config.json has to be in the workdir. The workdir is either the current directory, or it can be passed as an argument. E.g.: java -jar nxing.jar /home/docker to use /home/docker as workdir. The config.json must contain all the follwing fields:

Field	Data Type	Description
host	string	The address the server listens on.
port	integer	The port the server listens on.
maxImageSize	integer	The maximum size an image may have to be accepted, in bytes.
debug	boolean	Whether to start in debug mode or not. In debug mode, additional information is printed to the console.
useSsl	boolean	Whether to use ssl or not.
sslDir	string	The only field that may be null or omitted. If so and useSsl is true a self signed certificate will be generated and use to secure connections. Otherwise it has to point to a directory where the two files fullchain.pem and privkey.pem are located. Note that this path is not relative to workdir.

Example: { "port":7642, "host":"0.0.0.0", "debug":true, "sslDir":null, "useSsl":true, "maxImageSize":2097152, }

Authorization

If the service should only be used by some known users, you can give them an api token and enable authorization. To do this, simply store some api tokens in tokens.txt, one line per token (utf8), in the workdir. If this file is present and not empty, a client needs to authorize itselfe by sending the http Authorization header with the value set to an valid token.

List of Endpoints

POST /decode
	Requests:
		Decoding of code in the image
		Body-Format: Image bytes
	Returns:
		A 200 OK and the decoding result as body if everything worked
		A 400 Bad Request if the image did not contain something to decode or is not a png or jpg
		A 401 Unauthorized if the server requires authorization and no valid authorization was provided in the request
		A 413 Payload to Large if the content exceeds the maxImageSize
		A 500 Internal Server Error if something went wrong internally

Commands

While the service is running, there are several commands that can be executed:

Command	Description
help	Gives an overview to the available commands.
exit	Shoots the server down gracefully.
reload	Reloads the content of tokens.txt.
stats	Prints some statistics, such as how many decode requests where made and how many where successful.