oneOf:errorMessage is valid,but type:["string",null] errorMessage is invalid { "type": "object", "properties": { "keyword": { "oneOf": [ { "type": "string" }, { "type": "null" } ], "errorMessage": { "oneOf": "keyword必须为字符串" }, "title": "关键字" }, "keyword1": { "type": ["string","null"], "errorMessage": { "type": "关键字1必须为字符串" }, "title": "关键字" } }}