How to define JSON schema for object that holds Properties object?

Question

I need to create a JSON schema for object that will include java Properties object as one of its properties. The nested Properties object will be simply list of key=value. Both key and value are of type string. I failed to find any docs that describe how to define the schema that includes 2 new types.

shall it be something like:

{
"type": "object",
"name": "MyObj",
"properties": {
    "prop1": {
        "type": "string",
        "description": "prop1",
        "required": true
    },
    "props": {
        "type": "array",
        "items": {
            "type": "object"
            "properties": {
                "key": {
                    "type": "string",
                    "description": "key",
                    "required": true
                },
                "value": {
                    "type": "string",
                    "description": "the value",
                    "required": true
                }
            }
            "description": "the value",
            "required": true
        }
    }
}

}

Answer 1

The schema you have written (assuming the commas are fixed) describes data of the form:

{
    "prop1": "Some string property goes here",
    "props": [
        {"key": "foo", "value": "bar"},
        {"key": "foo2", "value": "bar2"},
        ...
    ]
}

If this is what you wanted, then you are already finished.

However, I do wonder why you are using key/value pairs in an array, when you could use a JSON object with string keys instead. Using the additionalProperties keyword, you could have a schema:

{
    "type": "object",
    "name": "MyObj",
    "properties": {
        "prop1": {
            "type": "string",
            "description": "prop1"
        },
        "props": {
            "type": "object",
            "additionalProperties": {
                "type": "string",
                "description": "string values"
            }
        }
    }
}

This describes a data format like:

{
    "prop1": "Some string property goes here",
    "props": {
        "foo": "bar",
        "foo2": "bar2"
    }
}

Answer 2

At W3 schools (JSON Syntax) you can read how the array should be defined.

There is no schema like the xsd for xml, however i've found an approach on json-schema.org. If you are able to, i'll advice to youse google-GSON library for JSON. You could Store key Value as "id" : "value" and build only one object, containing all requieed pairs:

{ "lang" : "EN" , "color" : "red" }

Your posted model is incorect, you can check it on jsonlint.com Here is a working version, i'm not sure if the modell is as expected.

{
    "type": "object",
    "name": "MyObj",
    "properties": [
        {
            "prop1": {
                "type": "string",
                "description": "prop1",
                "required": true
            },
            "props": {
                "type": "array",
                "items": {
                    "type": "object",
                    "properties": {
                        "key": {
                            "type": "string",
                            "description": "key",
                            "required": true
                        },
                        "value": {
                            "type": "string",
                            "description": "the value",
                            "required": true
                        }
                    },
                    "description": "the value",
                    "required": true
                }
            }
        }
    ]
}