JSON Validation Service

The JSON Validation Service (JVS) is a validator that allows a user to check JSON objects for compliance with the JSON grammar according to RFC 7159§.

Features

• Plain API
• Easy to deploy using provided Dockerfile
• Supports configurable logging based on Java Logging API via logging.properties file

Usage

A Simple Way

JSONValidationService service;

try {
    service = new JSONValidationService(); // use default parameters
    service.start();
} catch (JVSException e) {
    LOG.log(Level.SEVERE, "Service exception", e);
}

Customize Options

You have several ways to build JVSOptions and pass it to the JSONValidationService class constructor.

/* use default options */
JVSOptions options1 = new JVSOptions();
/* populate parameters from the configuration file */
JVSOptions options2 = new JVSOptions("config.file");
/* manually build your JVSOptions instance */
JVSOptions options3 = new JVSOptionsBuilder("localhost", 8081)
                      .setPath("/app")
                      .build();
/* or tune parameters from the file at runtime */
JVSOptions options4 = new JVSOptions("config")
                      .newBuilder()
                      .setPort(8080)
                      .setDelay(32)
                      .build()

/* and use like this */
new JSONValidationService(options4);

Configuration File

The configuration file is in JSON format with the following fields:

• host - a hostname or an IP address for the service to bind
• port - a port number that is used by the service
• backlog - a maximum number of incoming TCP connections
• path - a location of the service on a given host
• delay - the maximum time in seconds to wait until exchanges are finished

See jvs.properties file for an example.

Handling the Responses

1. If a received JSON is valid it is formatted to human-readable form and sent back.

2. If data in a request do not conform to the JSON grammar, the following response is sent:

    {
        "errorCode"  : 12,
        "errorMessage" : "plain language description of the problem",
        "errorPlace" : "the point where error has occurred",
        "resource"   : "filename taken from a URI",
        "request-id" : "the request id for easier tracking of errors"
    }

Below is a list of known errors:

Code	Meaning
1	Unterminated array
2	Unterminated object
3	Expected name
4	Expected ':'
5	Unexpected value
6	Expected value
7	Unterminated string
8	Unterminated comment
9	Malformed JSON
10	Unterminated escape sequence
11	Invalid escape sequence
12	JSON forbids NaN and infinities

Normally, JVS sends HTTPS OK responses with Content-Type: application/json in either case.

Deployment

Run and build the Docker image:

$ cd "the path where the Dockerfile is placed"
$ docker build -t jvs .
$ docker run --rm -d -p 80:80 jvs

Or you can fork this project, change it as you want to, and commit the changes. Then you can simply run:

$ docker run --rm -d -p 80:80 jvs https://example.com/your_repo.git

To test that JVS is working properly, make a POST request as shown below:

$ cat file.json # example of a JSON file
{
    "key" : "value"
}
$ curl -s --data-binary @file.json http://example.com[:port]/file.json

License

This project is licensed under the MIT License - see the LICENSE file for details

Acknowledgments

• The project is based on Google Gson library