Validate Json Schema

Question

I'm getting an error when using json-schema-validator API v4. I try to do :

final JsonValidator validator = new JsonValidator(JsonLoader.fromPath("schema.json"));
ValidationReport report = validator.validate(data);

but every time I get an error : # [schema]: unknown keyword contacts

schema.json :
{
    "contacts": {
        "description": "The list of contacts",
        "type": "array",
        "optional": true,
        "items": {
            "description": "A contact",
            "type": "object",
            "properties": {
                "givenName": {
                    "description": "Person's first name",
                    "type": "string",
                    "maxLength": 64,
                    "optional": true
                },
                "familyName": {
                    "description": "A person's last name",
                    "type": "string",
                    "maxLength": 64,
                    "optional": true
                }
            }
        }
    }
}

Regards

Answer 1

As far as I can intuit, your data looks like this-> json_data={"contacts":array}. If this is true, basically your outermost thing is an object (basically the full json object itself), for which you "might" need to define the schema starting from the "top level root" of your json as-> schema.json:

{
"description": "the outer json",
        "type": "object",
        "properties": {
            "contacts": {
                          "description": "The list of contacts",
                          "type": "array",
                          "optional": true,
                          "items": {
                                     "description": "A contact",
                                     "type": "object",
                                     "properties": {
                                     "givenName": {

etc.....

Forgive me for rough indentations. Also, I have not tested this, please see if it works, if it does not, I would suggest you to provide your json_data (example at least) and the API's examples so that one can try to locate where what is wrong.

Answer 2

Use AVJ. Instead of having your data validation and sanitization logic written as lengthy code, you can declare the requirements to your data with concise, easy to read and cross-platform JSON Schema or JSON Type Definition specifications and validate the data as soon as it arrives to your application.

// validationSchema.js

import Ajv from "ajv";
import addFormats from "ajv-formats";
import ajvErrors from "ajv-errors";

const schemas = {
  newUser: {
    {
      type: "object",
      properties: {
        lastName: {
          type: "string",
          minLength: 1,
          maxLength: 255
        },
        firstName: {
          type: "string",
          minLength: 1,
          maxLength: 255
        },
        description: {
          type: "string"
        },
        birthday: {
          type: "string",
          format: "date-time"
        },
        status: {
          type: "string",
          enum: ["ACTIVE", "DELETED"]
        },
      },
      required: ["name"]
    }
  }
};

const ajv = new Ajv({ allErrors: true });

addFormats(ajv);
ajvErrors(ajv /*, {singleError: true} */);

const mapErrors = (errorsEntry = []) => {
  const errors = errorsEntry.reduce(
    (
      acc,
      { instancePath = "", message = "", params: { missingProperty = "" } = {} }
    ) => {
      const key = (instancePath || missingProperty).replace("/", "");

      if (!acc[key]) {
        acc[key] = [];
      }

      acc[key].push(`${key} ${message}`);

      return acc;
    },
    []
  );

  return errors;
};

const validate = (schemaName, data) => {
  const v = ajv.compile(schemas[schemaName]);
  let valid = false,
    errors = [];

  valid = v(data);
  if (!valid) {
    errors = mapErrors(v.errors);
  }

  return { valid, errors };
};

export default { validate };

You can validate it like this:

import validationSchema from "your_path/validationSchema.js"

const user = {
  firstName: "",
  lastName: "",
  ....
};

const { valid, errors = [] } = validationSchema.validate("newUser", user);

if(valid){
  console.log("Data is valid!");
} else {
  console.log("Data is not valid!");
  console.log(errors);
}