json-schema-constraint-validator

A JSON Schema validator that allows inter-property constraints.

Available downloads (Gradle/maven)

This package is hosted by jitpack.io; the artifact is as follows:

Gradle:

Step 1. Add the JitPack repository to your build file

allprojects {
    repositories {
        maven { url 'https://jitpack.io' }
    }
}

Step 2. Add the dependency

dependencies {
        compile 'com.github.Cocoduf:json-schema-constraint-validator:-SNAPSHOT'
}

Maven:

Step 1. Add the JitPack repository to your build file

<repositories>
    <repository>
        <id>jitpack.io</id>
        <url>https://jitpack.io</url>
    </repository>
</repositories>

Step 2. Add the dependency

<dependency>
    <groupId>com.github.cocoduf</groupId>
    <artifactId>json-schema-constraints-validator</artifactId>
    <version>-SNAPSHOT</version>
</dependency>

Developing

Basic use of this library only requires the methods found in the JsonValidator.java file. Here's how to test some JSON:

JsonValidator jsonValidator = new JsonValidator();
jsonValidator.setSchema("raw json string" OR java.io.File instance);
boolean isJsonValid = jsonValidator.validateJson("raw json string" OR java.io.File instance);

Schema

Say you have an initial schema:

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "title": "Data",
  "type": "object",
  "properties": {
    "SOURCE": {
      "type": "number"
    },
    "TARGET": {
      "type": "number"
    }
  }
}

In order to add a constraint between SOURCE and TARGET, you must add the "constraints" property to SOURCE:

"SOURCE": {
  "type": "number",
  "constraints": [
  
  ]
}

A constraint is an object with a "type" and a "target".

"constraints": [
    {
      "type": "CONSTRAINT_TYPE",
      "target": "#/TARGET"
    }
]

Target must be a valid JSON Pointer (# being the root object).

Here is a table describing each available constraint type:

Source field	Constraint name	Target field	Required JSON Schema format
BOOLEAN, NUMBER, STRING, ARRAY, OBJECT	valueEqualTo	BOOLEAN, NUMBER, STRING, ARRAY, OBJECT
BOOLEAN, NUMBER, STRING, ARRAY, OBJECT	valueNotEqualTo	BOOLEAN, NUMBER, STRING, ARRAY, OBJECT
NUMBER	valueGreaterThan	NUMBER
NUMBER	valueGreaterThanOrEqualTo	NUMBER
NUMBER	valueLesserThan	NUMBER
NUMBER	valueLesserThanOrEqualTo	NUMBER
NUMBER, STRING	inArray	ARRAY
NUMBER, STRING	notInArray	ARRAY
STRING	priorTo	STRING	date-time
STRING	subsequentTo	STRING	date-time

Available date formats: "yyyy-MM-dd", "yyyy-MM-dd HH:mm:ss".

Examples

Note: There are plenty of examples in the test files.

Testing if a number is greater than an other number

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "title": "Data",
  "type": "object",
  "properties": {
    "SOURCE": {
      "type": "number",
      "constraints": [
        {
          "type": "valueGreaterThan",
          "target": "#/TARGET"
        }
      ]
    },
    "TARGET": {
      "type": "number"
    }
  }
}

Testing if a string is in an array

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "title": "Data",
  "type": "object",
  "properties": {
    "SOURCE": {
      "type": "string",
      "constraints": [
        {
          "type": "inArray",
          "target": "#/TARGET"
        }
      ]
    },
    "TARGET": {
      "type": "array"
    }
  }
}

Testing if a date is prior to an other date

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "title": "Data",
  "type": "object",
  "properties": {
    "SOURCE": {
      "type": "string",
      "constraints": [
        {
          "type": "priorTo",
          "target": "#/TARGET"
        }
      ],
      "format": "date"
    },
    "TARGET": {
      "type": "string",
      "format": "date"
    }
  }
}

Cocoduf/json-schema-constraint-validator