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java - 使用 spring-boot-2.2.1 删除 HATEOAS 链接中的 _embedded

问题描述

我正在使用 spring-boot-2.2.1 和 spring-HATEOAS。超媒体链接工作正常，但我在返回链接时看到属性，请在此处_embedded找到以下代码以供参考和 github 中的项目，

端点：

a) 将返回CollectionModel=> localhost:8099/api/v1/capability/list/noembedded

和

b) 将返回 List<EntityModel< Capability>> localhost:8099/api/v1/capability/list/

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>spring-boot-unittest</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring-boot-unittest</name>
    <description>Demo project for Spring Boot unit test</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-hateoas</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-mongodb</artifactId>
        </dependency>
        <dependency>
            <groupId>com.querydsl</groupId>
            <artifactId>querydsl-mongodb</artifactId>
            <version>4.1.4</version>
        </dependency>

        <dependency>
            <groupId>com.querydsl</groupId>
            <artifactId>querydsl-apt</artifactId>
            <version>4.1.4</version>
        </dependency>
        <!-- Embedded  MongoDB for Testing -->
        <dependency>
            <groupId>de.flapdoodle.embed</groupId>
            <artifactId>de.flapdoodle.embed.mongo</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springdoc</groupId>
            <artifactId>springdoc-openapi-ui</artifactId>
            <version>1.2.21</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>com.mysema.maven</groupId>
                <artifactId>apt-maven-plugin</artifactId>
                <version>1.1.3</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>process</goal>
                        </goals>
                        <configuration>
                            <outputDirectory>target/generated-sources/java</outputDirectory>
                            <!--<processor>com.querydsl.mongodb.morphia.MorphiaAnnotationProcessor</processor>-->
                            <processor>org.springframework.data.mongodb.repository.support.MongoAnnotationProcessor</processor>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>

控制器.Java

@RestController
@RequestMapping(value = "/api/v1/capability")
@RequiredArgsConstructor
@CrossOrigin
public class CapabilityController {

    private final CapabilityService capabilityService;
    private final CapabilityResourceAssembler capabilityResourceAssembler;

    @GetMapping(value = "/list")
    public CollectionModel<EntityModel<Capability>> getAllCapabilities() {
       List<EntityModel<Capability>> capabilities = capabilityService.listCapabilities().stream()
               .map(capability -> new EntityModel<>(capability,
                       linkTo(methodOn(CapabilityController.class).getCapabilityById(capability.getId())).withRel("getThisCapability"),
                       linkTo(methodOn(CapabilityController.class).getAllCapabilities()).withRel("getAllCapabilities")
               )).collect(Collectors.toList());
        return new CollectionModel<>(capabilities);
    }
}

实际响应

{
  "_embedded": {
    "capabilityList": [
      {
        "id": "sample",
        "techStack": "Java",
        "numOfDevelopers": 25,
        "numOfAvailableDevelopers": 10,
        "_links": {
          "getThisCapability": {
            "href": "http://localhost:8099/api/v1/capability/sample"
          },
          "getAllCapabilities": {
            "href": "http://localhost:8099/api/v1/capability/list"
          },
          "deleteThisCapability": {
            "href": "http://localhost:8099/api/v1/capability/sample"
          },
          "createCapability": {
            "href": "localhost:8099/api/v1/capability"
          }
        }
      }
    ]
  }
}

预期反应：

[
  {
    "id": "sample",
    "techStack": "Java",
    "numOfDevelopers": 25,
    "numOfAvailableDevelopers": 10,
    "_links": {
      "getThisCapability": {
        "href": "http://localhost:8099/api/v1/capability/sample"
      },
      "getAllCapabilities": {
        "href": "http://localhost:8099/api/v1/capability/list"
      }
    }
  }
]

我试过

spring.data.rest.defaultMediaType = 应用程序/json

spring.hateoas.use-hal-as-default-json-media-type=false

但是我仍然无法_embedded在响应中看到属性。谁能帮我找出问题所在。

我spring-boot-1.5.10在那里之前使用过，我可以在没有的情况下正确呈现链接_embedded，请参考这里。

在主类中添加下面的注释并且如果我返回 List 后它工作正常

@EnableHypermediaSupport(type = EnableHypermediaSupport.HypermediaType.HAL)

本地主机：9771/api/v1/capability/list

这会产生以下结果：

[
  {
    "capabilityId": "sample",
    "techStack": "Java",
    "numOfDevelopers": 25,
    "numOfAvailableDevelopers": 10,
    "_links": {
      "getThisCapability": {
        "href": "http://localhost:9771/api/v1/capability/sample"
      },
      "getAllCapabilities": {
        "href": "http://localhost:9771/api/v1/capability/list"
      }
    }
  }
]

不幸的是，它不适用于最新版本。任何帮助将非常感激。

标签： javaspringspring-bootspring-data-mongodbspring-hateoas

解决方案

如果我正确理解HAL 规范，那将是无效的 HAL，这就是为什么只要您CollectionModel在请求中返回 a，Spring HATEOAS 就不会产生此结果。请注意，集合也可能具有链接，如本示例文档中所述，该链接将位于_embedded属性中的_links属性旁边。

如果您真的想摆脱该_embedded属性并生成EntityModel<T>s 列表，那么如果您修改代码以返回 a ，它应该可以工作List<EntityModel<Capability>>。然后，您将丢失Spring HATEOAS 生成的_embedded和属性。_links这是您修改后的代码段：

@RestController
@RequestMapping(value = "/api/v1/capability")
@RequiredArgsConstructor
@CrossOrigin
public class CapabilityController {

    private final CapabilityService capabilityService;
    private final CapabilityResourceAssembler capabilityResourceAssembler;

    @GetMapping(value = "/list")
    public List<EntityModel<Capability>> getAllCapabilities() {
       List<EntityModel<Capability>> capabilities = capabilityService.listCapabilities().stream()
               .map(capability -> new EntityModel<>(capability,
                       linkTo(methodOn(CapabilityController.class).getCapabilityById(capability.getId())).withRel("getThisCapability"),
                       linkTo(methodOn(CapabilityController.class).getAllCapabilities()).withRel("getAllCapabilities")
               )).collect(Collectors.toList());
        return capabilities;
    }
}

我强烈建议您不要这样做，因为您失去了 Spring HATEOAS 的优势。

此外，我建议使用你的CapabilityResourceAssembler并通过使用创建EntityModel<Capability>实例，capabilityResourceAssembler.toModel(...)这样你就不必重复你在.map(...)函数中实现的代码。

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