java - openapi springboot 服务器生成器是否有损坏的线程模型？

Question

因此我们正在尝试使用 OpenAPI 生成器，但到目前为止我们得到了不同的结果。

重现步骤:

1. 下载 openapi 生成器 jar:wget https://repo1.maven.org/maven2/org/openapitools/openapi-generator/4.0.3/openapi-generator-4.0.3.jar
2. 为宠物店示例生成 springboot 服务器:java -jar openapi-generator-cli-4.0.3.jar generate -g spring -i https://raw.githubusercontent.com/OAI/OpenAPI-Specification/master/examples/v3.0/petstore.yaml

您最终会得到如下所示的 Controller 类:

package org.openapitools.api;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.context.request.NativeWebRequest;
import java.util.Optional;
@javax.annotation.Generated(value = "org.openapitools.codegen.languages.SpringCodegen", date = "2019-08-06T15:08:49.070+01:00[Europe/London]")

@Controller
@RequestMapping("${openapi.swaggerPetstore.base-path:/v1}")
public class PetsApiController implements PetsApi {

    private final NativeWebRequest request;

    @org.springframework.beans.factory.annotation.Autowired
    public PetsApiController(NativeWebRequest request) {
        this.request = request;
    }

    @Override
    public Optional<NativeWebRequest> getRequest() {
        return Optional.ofNullable(request);
    }

}

/**
 * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (4.0.3).
 * https://openapi-generator.tech
 * Do not edit the class manually.
 */
package org.openapitools.api;

import org.openapitools.model.Error;
import org.openapitools.model.Pet;
import io.swagger.annotations.*;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RequestPart;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.multipart.MultipartFile;

import javax.validation.Valid;
import javax.validation.constraints.*;
import java.util.List;
import java.util.Map;
import java.util.Optional;
@javax.annotation.Generated(value = "org.openapitools.codegen.languages.SpringCodegen", date = "2019-08-06T15:08:49.070+01:00[Europe/London]")

@Validated
@Api(value = "pets", description = "the pets API")
public interface PetsApi {

    default Optional<NativeWebRequest> getRequest() {
        return Optional.empty();
    }

    @ApiOperation(value = "Create a pet", nickname = "createPets", notes = "", tags={ "pets", })
    @ApiResponses(value = { 
        @ApiResponse(code = 201, message = "Null response"),
        @ApiResponse(code = 200, message = "unexpected error", response = Error.class) })
    @RequestMapping(value = "/pets",
        produces = { "application/json" }, 
        method = RequestMethod.POST)
    default ResponseEntity<Void> createPets() {
        return new ResponseEntity<>(HttpStatus.NOT_IMPLEMENTED);

    }


    @ApiOperation(value = "List all pets", nickname = "listPets", notes = "", response = Pet.class, responseContainer = "List", tags={ "pets", })
    @ApiResponses(value = { 
        @ApiResponse(code = 200, message = "A paged array of pets", response = Pet.class, responseContainer = "List"),
        @ApiResponse(code = 200, message = "unexpected error", response = Error.class) })
    @RequestMapping(value = "/pets",
        produces = { "application/json" }, 
        method = RequestMethod.GET)
    default ResponseEntity<List<Pet>> listPets(@ApiParam(value = "How many items to return at one time (max 100)") @Valid @RequestParam(value = "limit", required = false) Integer limit) {
        getRequest().ifPresent(request -> {
            for (MediaType mediaType: MediaType.parseMediaTypes(request.getHeader("Accept"))) {
                if (mediaType.isCompatibleWith(MediaType.valueOf("application/json"))) {
                    ApiUtil.setExampleResponse(request, "application/json", "null");
                    break;
                }
            }
        });
        return new ResponseEntity<>(HttpStatus.NOT_IMPLEMENTED);

    }


    @ApiOperation(value = "Info for a specific pet", nickname = "showPetById", notes = "", response = Pet.class, tags={ "pets", })
    @ApiResponses(value = { 
        @ApiResponse(code = 200, message = "Expected response to a valid request", response = Pet.class),
        @ApiResponse(code = 200, message = "unexpected error", response = Error.class) })
    @RequestMapping(value = "/pets/{petId}",
        produces = { "application/json" }, 
        method = RequestMethod.GET)
    default ResponseEntity<Pet> showPetById(@ApiParam(value = "The id of the pet to retrieve",required=true) @PathVariable("petId") String petId) {
        getRequest().ifPresent(request -> {
            for (MediaType mediaType: MediaType.parseMediaTypes(request.getHeader("Accept"))) {
                if (mediaType.isCompatibleWith(MediaType.valueOf("application/json"))) {
                    ApiUtil.setExampleResponse(request, "application/json", "null");
                    break;
                }
            }
        });
        return new ResponseEntity<>(HttpStatus.NOT_IMPLEMENTED);

    }

}

所以我的问题是:我能找到的所有内容都表明 Spring Controller 是多线程的，可以同时处理多个请求。代码生成器坏了吗？我的解释完全错误吗？

PetsApiController 的构造函数让我停顿了一下。如果每个请求 Autowiring 一次，那么这意味着每个请求只有一个？

    @org.springframework.beans.factory.annotation.Autowired
    public PetsApiController(NativeWebRequest request) {
        this.request = request;
    }

Answer 1

swagger 代码生成器是出了名的不好，我的 friend 说生成器有广度但没有深度。您可以为各种语言和框架生成骨架，但它们有严重的局限性。例如，尝试使用 Page<Something> 从 SwaggerDoc 生成一个好的框架。或其他泛型。我会非常遗憾地说，它们几乎没有实用性，而且这些工具往往只能以相反的方式可靠地工作，即先编码，然后生成 SwaggerDoc。

我工作过的一个地方有一个很棒的概念，我真的很喜欢它，你可以在实现它之前先设计你的 API，这听起来像是你正在尝试做的。一些 IDE 甚至支持生成代码，并且有用于构建工具的插件，例如 maven gradle 等，可以从您的 yaml 生成代码。

但在实践中，我花了几天时间试图从这些工具中获得理想的结果并放弃了。我认为真正的问题是 Swagger/OpenAPI 仍然被广泛视为文档工具，而不是设计工具。我还认为，尝试创建一个包罗万象的项目生成器从一开始就注定要失败。

我自己尝试自定义生成器使用的 mustache 模板，但 Java 中的泛型是一场噩梦，你无法获得正确的工作流程，因此我会更改 SwaggerDoc 然后更新我的代码，因为我的方法是生成一个接口(interface)，然后实现该接口(interface)，但注释没有被继承，所以我不得不复制所有代码，这意味着没有任何好处。