【发布时间】：2020-05-01 18:54:50
【问题描述】：
我正在尝试从 springfox-swagger2 (OpenAPI 2) 迁移到 springdoc-openapi-ui (OpenAPI 3)，以生成 swagger 文档。
这是一个示例路线：
@RequestMapping("/api/object/")
public interface IObjectController {
@RequestMapping(path = "v1/{param}", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
@ResponseStatus(value = HttpStatus.OK)
ObjectDto getObjectByParamV1(@PathVariable("param") String code);
}
Swagger 生成与springfox-swagger2 配合得很好，但是我在springdoc 上遇到以下问题：
Null key for a Map not allowed in JSON (use a converting NullKeySerializer?)
(through reference chain: io.swagger.v3.oas.models.OpenAPI["paths"]->
io.swagger.v3.oas.models.Paths["/api/object/v1/{param}"]->io.swagger.v3.oas.models.PathItem["get"]->
io.swagger.v3.oas.models.Operation["responses"]->io.swagger.v3.oas.models.responses.ApiResponses["null"])
确实，OpenAPI 尝试序列化以下对象：
responses: class ApiResponses {
{null=class ApiResponse {
description: default response
headers: null
content: class Content {
{*/*=class MediaType {
schema: class ComposedSchema {
class Schema {
type: null
format: null
$ref: null
description: null
title: null
multipleOf: null
maximum: null
exclusiveMaximum: null
minimum: null
exclusiveMinimum: null
maxLength: null
minLength: null
pattern: null
maxItems: null
minItems: null
uniqueItems: null
maxProperties: null
minProperties: null
required: null
not: null
properties: null
additionalProperties: null
nullable: null
readOnly: null
writeOnly: null
example: null
externalDocs: null
deprecated: null
discriminator: null
xml: null
}
allOf: null
anyOf: null
oneOf: [class Schema {
type: object
format: null
$ref: null
description: null
title: null
multipleOf: null
maximum: null
exclusiveMaximum: null
minimum: null
exclusiveMinimum: null
maxLength: null
minLength: null
pattern: null
maxItems: null
minItems: null
uniqueItems: null
maxProperties: null
minProperties: null
required: null
not: null
properties: null
additionalProperties: null
nullable: null
readOnly: null
writeOnly: null
example: null
externalDocs: null
deprecated: null
discriminator: null
xml: null
}, class StringSchema {
class Schema {
type: string
format: null
$ref: null
description: null
title: null
multipleOf: null
maximum: null
exclusiveMaximum: null
minimum: null
exclusiveMinimum: null
maxLength: null
minLength: null
pattern: null
maxItems: null
minItems: null
uniqueItems: null
maxProperties: null
minProperties: null
required: null
not: null
properties: null
additionalProperties: null
nullable: null
readOnly: null
writeOnly: null
example: null
externalDocs: null
deprecated: null
discriminator: null
xml: null
}
}]
}
examples: null
example: null
encoding: null
}}
}
links: null
extensions: null
$ref: null
}, 200=class ApiResponse {
description: OK
headers: null
content: class Content {
{application/json=class MediaType {
schema: class Schema {
type: null
format: null
$ref: #/components/schemas/ObjectDto
description: null
title: null
multipleOf: null
maximum: null
exclusiveMaximum: null
minimum: null
exclusiveMinimum: null
maxLength: null
minLength: null
pattern: null
maxItems: null
minItems: null
uniqueItems: null
maxProperties: null
minProperties: null
required: null
not: null
properties: null
additionalProperties: null
nullable: null
readOnly: null
writeOnly: null
example: null
externalDocs: null
deprecated: null
discriminator: null
xml: null
}
examples: null
example: null
encoding: null
}}
}
links: null
extensions: null
$ref: null
}}
extensions: null
}
如您所见，ApiResponses 中有一个空的ApiResponse 对象，奇怪的是有一个null 键，然后序列化在jackon 的MapSerializer.serialize() 中失败：
// What is this _suppressNulls ?!
// _suppressableValue IS null, but is not suppressed
if ((_suppressableValue != null) || _suppressNulls) {
serializeOptionalFields(value, gen, provider, _suppressableValue);
}
无论我使用多少 Swagger 注释（@Operation，添加@ApiResponse...），这个null ApiResponse 仍然存在。我不明白这是从哪里来的，尤其是 suppressNull 只影响 values 而不是 keys，根据 MapSerializer.serializeOptionalFields()。
如何删除这个 null-keyed ApiResponse ？
【问题讨论】：
标签： spring swagger openapi springdoc