JSON Request Validation

A collection of tools for validating JSON requests and reporting validation failures using JSON path notation.

This library is primarily intended for use with services using generated JaxRS types from raml-for-jaxrs.

Usage

Note	This library is primarily intended for use with, and is most convenient in Kotlin, but it does support full interoperability with Java as well.

build.gradle.kts

dependencies {
  implementation("org.veupathdb.lib:jpath-request-validation:0.1.1")
}

Request Field Validation

Kotlin

fun MyRequestBody.validate(): ValidationErrors {
  val errors = ValidationErrors()

  // ensure the "name" field on the request body is not null and has a length
  // >= 3 and <= 24
  name.reqCheckLength(JsonField.NAME, 3, 24, errors)

  // if the "description" field is not null, ensure it has a length <= 4000
  description.optCheckMaxLength(JsonField.DESCRIPTION, 4000, errors)

  // call the validate function on the "options" object of type MyOptionsField,
  // passing in the name of the field to use when forming JSON paths to
  // sub-fields.
  options.validate(JsonField.OPTIONS, errors)

  return errors
}

fun MyOptionsField.validate(jPath: String, errors: ValidationErrors) {
  // make the subpath for the "fields" list ahead of time so we aren't doing
  // string concat in the loop
  val subPath = jPath..JsonField.FIELDS

  // require that the "fields" array on the object is not null
  fields.require(subPath, errors) {
    // iterate through the strings in the "fields" array
    forEachIndexed { i, field ->
      // ensure the fields are not blank
      field.checkNonBlank(subPath, i, errors)
    }
  }
}

Java

import static org.veupathdb.lib.request.validation.Validation.checkNonBlank;
import static org.veupathdb.lib.request.validation.Validation.optCheckMaxLength;
import static org.veupathdb.lib.request.validation.Validation.require;
import static org.veupathdb.lib.request.validation.Validation.reqCheckLength;

public ValidationErrors validate(MyRequestBody body) {
  var errors = new ValidationErrors();

  // ensure the "name" field on the request body is not null and has a length
  // >= 3 and <= 24
  reqCheckLength(body.name, JsonField.NAME, 3, 24, errors);

  // if the "description" field is not null, ensure it has a length <= 4000
  optCheckMaxLength(body.description, JsonField.DESCRIPTION, 4000, errors);

  // call the validate function with the "options" object of type
  // MyOptionsField, including the name of the field to use when forming JSON
  // paths to sub-fields.
  validate(body.options, JsonField.OPTIONS, errors);
}

private validate(MyOptionsField options, String jPath, ValidationErrors errors) {
  // make the subpath for the "fields" list ahead of time so we aren't doing
  // string concat in the loop
  var subPath = JPath.append(jPath, JsonField.FIELDS);

  // require that the "fields" array on the object is not null
  require(options.fields, subPath, errors, fields -> {
    // iterate through the strings in the "fields" array
    for (var i = 0; i < fields.size(); i++) {
      // ensure the fields are not blank
      checkNonBlank(fields.get(i), subPath, i, errors);
    }
  });
}

Validation Output

Using the code samples above as the setup, the output could resemble the following:

{
  "byKey": {
    "name": [ "must not be null" ],
    "description": [ "exceeds the max allowed length of 4000 bytes" ],
    "options.fields[1]": [ "must not be blank" ],
    "options.fields[8]": [ "must not be blank" ]
  }
}

License

   Copyright 2023 VEuPathDB

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.