JSON schema中allOf、anyOf、oneOf和not的作用和用法

參考文檔：combine schemas

The keywords used to combine schemas are:

• allOf: Must be valid against all of the subschemas (校驗對象要滿足所有子schema)
• anyOf: Must be valid against any of the subschemas (校驗對象要滿足至少一個子schema)
• oneOf: Must be valid against exactly one of the subschemas (校驗對象要滿足其中一個子schema)

All of these keywords must be set to an array, where each item is a schema.
In addition, there is:

• not: Must not be valid against the given schema

待校驗內容

待校驗內容：

{
    "count": 50
}

allOf

schema示例：

{
	"definitions": {},
	"$schema": "http://json-schema.org/draft-07/schema#",
	"$id": "http://example.com/root.json",
	"type": "object",
	"required": [],
	"properties": {
		"count": {
			"$id": "#/properties/count",
			"allOf": [{
			  "type": "number"
			},
			{
			  "minimum": 90
			}]
		}
	}
}

校驗結果：

{
    "schemaLocation": "#/properties/count",
    "pointerToViolation": "#/count",
    "causingExceptions": [
        {
            "schemaLocation": "#/properties/count/allOf/1",
            "pointerToViolation": "#/count",
            "causingExceptions": [],
            "keyword": "minimum",
            "message": "50 is not greater or equal to 90"
        }
    ],
    "keyword": "allOf",
    "message": "#: only 1 subschema matches out of 2",
    "validateResult": "FAILED"
}

所有條件滿足時，校驗纔會通過

anyOf

schema示例：

{
	"definitions": {},
	"$schema": "http://json-schema.org/draft-07/schema#",
	"$id": "http://example.com/root.json",
	"type": "object",
	"required": [],
	"properties": {
		"count": {
			"$id": "#/properties/count",
			"anyOf": [{
			  "type": "number"
			},
			{
			  "minimum": 20
			}]
		}
	}
}

校驗結果：
校驗 type 和 mininum，只要有一個滿足條件，校驗就可以成功

oneOf

schema示例：

{
	"definitions": {},
	"$schema": "http://json-schema.org/draft-07/schema#",
	"$id": "http://example.com/root.json",
	"type": "object",
	"required": [],
	"properties": {
		"count": {
			"$id": "#/properties/count",
			"oneOf": [{
			  "type": "number"
			},
			{
			  "minimum": 20
			}]
		}
	}
}

校驗結果：

{
    "schemaLocation": "#/properties/count",
    "pointerToViolation": "#/count",
    "causingExceptions": [],
    "keyword": "oneOf",
    "message": "#: 2 subschemas matched instead of one",
    "validateResult": "FAILED"
}

有且僅有一個條件滿足時，校驗才能通過

not

schema示例：

{
	"definitions": {},
	"$schema": "http://json-schema.org/draft-07/schema#",
	"$id": "http://example.com/root.json",
	"type": "object",
	"required": [],
	"properties": {
		"count": {
			"$id": "#/properties/count",
			"not": {
			  "type": "number"
			}
		}
	}
}

校驗結果：

{
    "schemaLocation": "#/properties/count",
    "pointerToViolation": "#/count",
    "causingExceptions": [],
    "keyword": "not",
    "message": "subject must not be valid against schema {\"type\":\"number\"}",
    "validateResult": "FAILED"
}

不滿足校驗條件時，校驗才能通過

複雜示例

待校驗內容

{
    "ARRAY": [
        {
            "item": 2
        },
        {
            "item": "true"
        }
    ]
}

schema示例

{
    "definitions": {},
    "$schema": "http://json-schema.org/draft-07/schema#",
    "$id": "http://example.com/root.json",
    "type": "object",
    "required": [],
    "properties": {
        "ARRAY": {
            "$id": "#/properties/ARRAY",
            "type": "array",
            "items": {
                "$id": "#/properties/ARRAY/items",
                "type": "object",
                "required": [],
                "oneOf": [
                    {
                        "properties": {
                            "item": {
                                "$id": "#/properties/ARRAY/items/properties/item",
                                "type": "number",
                                "minimum": 1
                            }
                        }
                    },
                    {
                        "properties": {
                            "item": {
                                "$id": "#/properties/ARRAY/items/properties/item",
                                "type": "string",
                                "parttern": "true"
                            }
                        }
                    }
                ]
            }
        }
    }
}

數組元素可能存在不同類型的取值，這裏對數組元素進行了多種可能性的校驗