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當客戶端服務中的Feign客戶端使用時，Spring Data Rest Hateoas Resources對象爲空

2016-10-25 87 views
3

我最近嘗試使用Spring Boot 1.4.1和Spring Cloud Camden SR1從此video和此github repo複製Spring雲示例，並遇到問題。當客戶端服務使用Feign客戶端調用生產者服務時，反序列化的資源沒有內容或鏈接。當客戶端服務中的Feign客戶端使用時，Spring Data Rest Hateoas Resources對象爲空

挖掘機經過進一步看起來問題已與MappingJackson2HttpMessageConverter做，這是傑克遜ObjectMapper。當我看着由佯客戶的SpringDecoder使用HttpMessageConverters我看到2個MappingJackson2HttpMessageConverters但無論是轉換器的ObjectMappers的有Jackson2HalModule註冊。

春數據休息預訂服務應用類：

@EnableDiscoveryClient 
@SpringBootApplication 
public class ReservationServiceApplication { 
    public static void main(String[] args) { 
     SpringApplication.run(ReservationServiceApplication.class, args); 
    } 
}

訂座艙位：

@Entity 
public class Reservation extends BaseEntity { 
    private String reservationName; 

    public Reservation(String reservationName) { 
     this.reservationName = reservationName; 
    } 

    protected Reservation() {} 

    public String getReservationName() { 
     return reservationName; 
    } 
}

的BaseEntity類具有ID和版本。

ReservationRepository類：

@RepositoryRestResource 
public interface ReservationRepository extends CrudRepository<Reservation, Integer> { 
}

預訂服務的pom.xml：

<?xml version="1.0" encoding="UTF-8"?> 
<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0" 
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> 
    <modelVersion>4.0.0</modelVersion> 

    <groupId>com.example</groupId> 
    <artifactId>reservation-service</artifactId> 
    <version>0.0.1-SNAPSHOT</version> 
    <packaging>jar</packaging> 

    <name>reservation-service</name> 
    <description>CRUD Service for Reservations</description> 

    <parent> 
     <groupId>org.springframework.boot</groupId> 
     <artifactId>spring-boot-starter-parent</artifactId> 
     <version>1.4.1.RELEASE</version> 
     <relativePath /> <!-- lookup parent from repository --> 
    </parent> 

    <properties> 
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> 
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> 
     <java.version>1.8</java.version> 
     <jackson.version>2.8.4</jackson.version> 
    </properties> 

    <dependencyManagement> 
     <dependencies> 
      <dependency> 
       <groupId>org.springframework.cloud</groupId> 
       <artifactId>spring-cloud-dependencies</artifactId> 
       <version>Camden.SR1</version> 
       <type>pom</type> 
       <scope>import</scope> 
      </dependency> 
     </dependencies> 
    </dependencyManagement> 

    <dependencies> 
     <!-- Spring Dependencies --> 
     <dependency> 
      <groupId>org.springframework.boot</groupId> 
      <artifactId>spring-boot-starter-actuator</artifactId> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.cloud</groupId> 
      <artifactId>spring-cloud-starter-sleuth</artifactId> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.cloud</groupId> 
      <artifactId>spring-cloud-starter-zipkin</artifactId> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.boot</groupId> 
      <artifactId>spring-boot-starter-data-rest</artifactId> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.boot</groupId> 
      <artifactId>spring-boot-starter-hateoas</artifactId> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.boot</groupId> 
      <artifactId>spring-boot-starter-web</artifactId> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.boot</groupId> 
      <artifactId>spring-boot-starter-data-jpa</artifactId> 
      <exclusions> 
       <exclusion> 
        <artifactId>tomcat-jdbc</artifactId> 
        <groupId>org.apache.tomcat</groupId> 
       </exclusion> 
      </exclusions> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.boot</groupId> 
      <artifactId>spring-boot-starter-logging</artifactId> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.cloud</groupId> 
      <artifactId>spring-cloud-starter-config</artifactId> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.cloud</groupId> 
      <artifactId>spring-cloud-starter-eureka</artifactId> 
     </dependency> 

     <!-- Jackson Dependencies --> 
     <dependency> 
      <groupId>com.fasterxml.jackson.core</groupId> 
      <artifactId>jackson-core</artifactId> 
      <version>${jackson.version}</version> 
     </dependency> 
     <dependency> 
      <groupId>com.fasterxml.jackson.core</groupId> 
      <artifactId>jackson-annotations</artifactId> 
      <version>${jackson.version}</version> 
     </dependency> 
     <dependency> 
      <groupId>com.fasterxml.jackson.core</groupId> 
      <artifactId>jackson-databind</artifactId> 
      <version>${jackson.version}</version> 
     </dependency> 
     <dependency> 
      <groupId>com.fasterxml.jackson.datatype</groupId> 
      <artifactId>jackson-datatype-jsr310</artifactId> 
      <version>${jackson.version}</version> 
     </dependency> 
     <dependency> 
      <groupId>com.fasterxml.jackson.datatype</groupId> 
      <artifactId>jackson-datatype-jdk8</artifactId> 
      <version>${jackson.version}</version> 
     </dependency> 
     <dependency> 
      <groupId>com.fasterxml.jackson.module</groupId> 
      <artifactId>jackson-module-parameter-names</artifactId> 
      <version>${jackson.version}</version> 
     </dependency> 

     <!-- Other Dependencies --> 
     <dependency> 
      <groupId>javax.inject</groupId> 
      <artifactId>javax.inject</artifactId> 
      <version>1</version> 
     </dependency> 
     <dependency> 
      <groupId>org.apache.commons</groupId> 
      <artifactId>commons-lang3</artifactId> 
      <version>3.4</version> 
     </dependency> 
     <dependency> 
      <groupId>org.apache.commons</groupId> 
      <artifactId>commons-collections4</artifactId> 
      <version>4.1</version> 
     </dependency> 
     <dependency> 
      <groupId>org.flywaydb</groupId> 
      <artifactId>flyway-core</artifactId> 
      <version>4.0.3</version> 
     </dependency> 

     <dependency> 
      <groupId>com.h2database</groupId> 
      <artifactId>h2</artifactId> 
      <scope>runtime</scope> 
     </dependency> 
     <dependency> 
      <groupId>com.zaxxer</groupId> 
      <artifactId>HikariCP</artifactId> 
      <version>2.5.0</version> 
      <scope>runtime</scope> 
     </dependency> 
     <dependency> 
      <groupId>org.hibernate</groupId> 
      <artifactId>hibernate-java8</artifactId> 
      <version>5.0.9.Final</version> 
      <scope>runtime</scope> 
     </dependency> 

     <dependency> 
      <groupId>org.springframework.boot</groupId> 
      <artifactId>spring-boot-starter-test</artifactId> 
      <scope>test</scope> 
     </dependency> 

     <dependency> 
      <groupId>org.springframework.boot</groupId> 
      <artifactId>spring-boot-devtools</artifactId> 
      <optional>true</optional> 
     </dependency> 
    </dependencies> 

    <build> 
     <plugins> 
      <plugin> 
       <groupId>org.springframework.boot</groupId> 
       <artifactId>spring-boot-maven-plugin</artifactId> 
      </plugin> 
     </plugins> 
    </build> 
</project>

預訂客戶端應用程序類：

@EnableFeignClients 
@EnableDiscoveryClient 
@SpringBootApplication 
public class ReservationClientApplication { 
    public static void main(String[] args) { 
     SpringApplication.run(ReservationClientApplication.class, args); 
    } 
}

預訂客戶假死Client類：

@FeignClient("reservation-service") 
public interface ReservationServiceClient { 
    @RequestMapping(method = RequestMethod.GET, value = "reservations") 
    Resources<Reservation> getReservations(); 
}

預訂客戶ReservationApiGateway控制器類：

@RestController 
@RequestMapping("reservations") 
public class ReservationApiGateway { 
    private final ReservationServiceClient client; 

    public ReservationApiGateway(ReservationServiceClient client) { 
     this.client = client; 
    } 

    @GetMapping 
    public Collection<Reservation> reservations() { 
     return client.getReservations().getContent(); 
    } 
}

預訂客戶端的pom.xml

http://maven.apache.org/xsd/maven-4.0.0.xsd「> 4.0 .0

<groupId>com.example</groupId> 
    <artifactId>reservation-client</artifactId> 
    <version>0.0.1-SNAPSHOT</version> 
    <packaging>jar</packaging> 

    <name>reservation-client</name> 
    <description>Example reservation client</description> 

    <parent> 
     <groupId>org.springframework.boot</groupId> 
     <artifactId>spring-boot-starter-parent</artifactId> 
     <version>1.4.1.RELEASE</version> 
     <relativePath /> <!-- lookup parent from repository --> 
    </parent> 

    <properties> 
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> 
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> 
     <java.version>1.8</java.version> 
     <jackson.version>2.8.4</jackson.version> 
    </properties> 

    <dependencyManagement> 
     <dependencies> 
      <dependency> 
       <groupId>org.springframework.cloud</groupId> 
       <artifactId>spring-cloud-dependencies</artifactId> 
       <version>Camden.SR1</version> 
       <type>pom</type> 
       <scope>import</scope> 
      </dependency> 
     </dependencies> 
    </dependencyManagement> 

    <dependencies> 
     <dependency> 
      <groupId>org.springframework.boot</groupId> 
      <artifactId>spring-boot-starter-actuator</artifactId> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.cloud</groupId> 
      <artifactId>spring-cloud-starter-config</artifactId> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.cloud</groupId> 
      <artifactId>spring-cloud-starter-eureka</artifactId> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.cloud</groupId> 
      <artifactId>spring-cloud-starter-sleuth</artifactId> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.cloud</groupId> 
      <artifactId>spring-cloud-starter-zipkin</artifactId> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.boot</groupId> 
      <artifactId>spring-boot-devtools</artifactId> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.boot</groupId> 
      <artifactId>spring-boot-starter-hateoas</artifactId> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.boot</groupId> 
      <artifactId>spring-boot-starter-web</artifactId> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.cloud</groupId> 
      <artifactId>spring-cloud-starter-feign</artifactId> 
     </dependency> 
     <dependency> 
      <groupId>org.springframework.cloud</groupId> 
      <artifactId>spring-cloud-starter-zuul</artifactId> 
     </dependency> 

     <!-- Jackson Dependencies --> 
     <dependency> 
      <groupId>com.fasterxml.jackson.core</groupId> 
      <artifactId>jackson-core</artifactId> 
      <version>${jackson.version}</version> 
     </dependency> 
     <dependency> 
      <groupId>com.fasterxml.jackson.core</groupId> 
      <artifactId>jackson-annotations</artifactId> 
      <version>${jackson.version}</version> 
     </dependency> 
     <dependency> 
      <groupId>com.fasterxml.jackson.core</groupId> 
      <artifactId>jackson-databind</artifactId> 
      <version>${jackson.version}</version> 
     </dependency> 
     <dependency> 
      <groupId>com.fasterxml.jackson.datatype</groupId> 
      <artifactId>jackson-datatype-jsr310</artifactId> 
      <version>${jackson.version}</version> 
     </dependency> 
     <dependency> 
      <groupId>com.fasterxml.jackson.datatype</groupId> 
      <artifactId>jackson-datatype-jdk8</artifactId> 
      <version>${jackson.version}</version> 
     </dependency> 
     <dependency> 
      <groupId>com.fasterxml.jackson.module</groupId> 
      <artifactId>jackson-module-parameter-names</artifactId> 
      <version>${jackson.version}</version> 
     </dependency> 

     <!-- Other Dependencies --> 
     <dependency> 
      <groupId>org.apache.commons</groupId> 
      <artifactId>commons-lang3</artifactId> 
      <version>3.4</version> 
     </dependency> 
     <dependency> 
      <groupId>org.apache.commons</groupId> 
      <artifactId>commons-collections4</artifactId> 
      <version>4.1</version> 
     </dependency> 

     <dependency> 
      <groupId>org.springframework.boot</groupId> 
      <artifactId>spring-boot-starter-test</artifactId> 
      <scope>test</scope> 
     </dependency> 
    </dependencies> 

    <build> 
     <plugins> 
      <plugin> 
       <groupId>org.springframework.boot</groupId> 
       <artifactId>spring-boot-maven-plugin</artifactId> 
      </plugin> 
     </plugins> 
    </build> 
</project>

當我點擊客戶端上的/預留端點時，我得到一個空的JSON數組返回（[]）。當我在假客戶端上啓用FULL日誌功能時，我看到預訂服務中的正確預訂。

最後，我嘗試添加：

@EnableHypermediaSupport(type=EnableHypermediaSupport.HypermediaType.HAL)

到預約的客戶端應用程序類。這導致預留資源被反序列化並由客戶端正確返回。不幸的是，我有一些其他類，我試圖讓Java 8 LocalDateTime字段需要在ObjectMapper上註冊Java 8 Jackson模塊，但是當我查看所使用的ObjectMapper時，唯一註冊的模塊是Jackson2HalModule。

我真的很感激任何意見，如果我這樣做不正確或如果存在一個錯誤。謝謝！

來源

2016-10-25 Trevor Smith

回答

3

經過更多的挖掘，我能夠解決這個問題。客戶端應用程序需要spring-data-rest依賴性來正確設置消息轉換器。不幸的是，考慮到客戶端應用程序不需要彈簧數據存儲庫，這似乎有點違反直覺。

來源

2016-11-08 17:01:10

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