java - Spring Boot 2 - Autowiring 服务时对 Feign 客户端的依赖性不满足

Question

我的情况非常简单，现在我已经尝试了一些方法，但找不到导致此问题的原因。它声称它不能 Autowiring Feign 客户端类，尽管这是我在 Spring Boot 1.5.9 中这样做的方式。至少我很确定。尽管我在 mock 这个客户，但我所有的单元测试都运行良好。以前它是导入库的一部分，但是为了消除我没有正确定位 bean 的可能性，我只是将它添加到同一个项目中。

我对 Spring 或 Feign 不是最有经验的，所以我想知道我在这里缺少的东西是否很明显。

简单的假客户端:

@FeignClient(name = "my-other-service")
public interface OtherServiceClient {

    @GetMapping(value = "/foo/{fooId}")
    @ResponseBody
    String getFoo(@PathVariable int fooId);
}

主要应用类:

@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
// Had a component scan here when in other module
public class MyServiceApplication {

    public static void main(String[] args) {
        SpringApplication.run(MyServiceApplication.class, args);
    }
}

依赖feign客户端的服务:

@Service
public class FooService {
    private final FooRepository fooRepository;
    private final BarRepository barRepository;
    private OtherServiceClient otherServiceClient;

    @Autowired
    public OrderService(
            FooRepository fooRepository,
            BarRepository barRepository,
            OtherServiceClient otherServiceClient) {
        this.fooRepository= fooRepository;
        this.barRepository = barRepository;
        this.otherServiceClient = otherServiceClient;
    }

因为它可能是一个自动配置，这里是配置报告:

============================
CONDITIONS EVALUATION REPORT
============================


Positive matches:
-----------------

   ConfigServiceBootstrapConfiguration#configServicePropertySource matched:
      - @ConditionalOnProperty (spring.cloud.config.enabled) matched (OnPropertyCondition)
      - @ConditionalOnMissingBean (types: org.springframework.cloud.config.client.ConfigServicePropertySourceLocator; SearchStrategy: all) did not find any beans (OnBeanCondition)

   ConfigurationPropertiesRebinderAutoConfiguration matched:
      - @ConditionalOnBean (types: org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor; SearchStrategy: all) found bean 'org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor' (OnBeanCondition)

   ConfigurationPropertiesRebinderAutoConfiguration#configurationPropertiesBeans matched:
      - @ConditionalOnMissingBean (types: org.springframework.cloud.context.properties.ConfigurationPropertiesBeans; SearchStrategy: current) did not find any beans (OnBeanCondition)

   ConfigurationPropertiesRebinderAutoConfiguration#configurationPropertiesRebinder matched:
      - @ConditionalOnMissingBean (types: org.springframework.cloud.context.properties.ConfigurationPropertiesRebinder; SearchStrategy: current) did not find any beans (OnBeanCondition)

   EncryptionBootstrapConfiguration matched:
      - @ConditionalOnClass found required class 'org.springframework.security.crypto.encrypt.TextEncryptor'; @ConditionalOnMissingClass did not find unwanted class (OnClassCondition)

   PropertyPlaceholderAutoConfiguration#propertySourcesPlaceholderConfigurer matched:
      - @ConditionalOnMissingBean (types: org.springframework.context.support.PropertySourcesPlaceholderConfigurer; SearchStrategy: current) did not find any beans (OnBeanCondition)


Negative matches:
-----------------

   ConfigServiceBootstrapConfiguration.RetryConfiguration:
      Did not match:
         - @ConditionalOnClass did not find required class 'org.springframework.retry.annotation.Retryable' (OnClassCondition)

   DiscoveryClientConfigServiceBootstrapConfiguration:
      Did not match:
         - @ConditionalOnProperty (spring.cloud.config.discovery.enabled) did not find property 'spring.cloud.config.discovery.enabled' (OnPropertyCondition)

   EncryptionBootstrapConfiguration.RsaEncryptionConfiguration:
      Did not match:
         - Keystore nor key found in Environment (EncryptionBootstrapConfiguration.KeyCondition)
      Matched:
         - @ConditionalOnClass found required class 'org.springframework.security.rsa.crypto.RsaSecretEncryptor'; @ConditionalOnMissingClass did not find unwanted class (OnClassCondition)

   EncryptionBootstrapConfiguration.VanillaEncryptionConfiguration:
      Did not match:
         - @ConditionalOnMissingClass found unwanted class 'org.springframework.security.rsa.crypto.RsaSecretEncryptor' (OnClassCondition)

   EurekaDiscoveryClientConfigServiceBootstrapConfiguration:
      Did not match:
         - @ConditionalOnProperty (spring.cloud.config.discovery.enabled) did not find property 'spring.cloud.config.discovery.enabled' (OnPropertyCondition)
      Matched:
         - @ConditionalOnClass found required class 'org.springframework.cloud.config.client.ConfigServicePropertySourceLocator'; @ConditionalOnMissingClass did not find unwanted class (OnClassCondition)

pom 的相关部分...我正在使用 Maven。

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.0.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>
    <spring-cloud.version>Finchley.BUILD-SNAPSHOT</spring-cloud.version>

    <spring-restdocs.version>2.0.0.RELEASE</spring-restdocs.version>
    <snippetsDirectory>${project.build.directory}/generated-snippets</snippetsDirectory>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-security</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-config</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-openfeign</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-oauth2</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>com.oracle</groupId>
        <artifactId>ojdbc14</artifactId>
        <version>10.2.0</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.datatype</groupId>
        <artifactId>jackson-datatype-jdk8</artifactId>
        <version>2.9.4</version>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.hsqldb</groupId>
        <artifactId>hsqldb</artifactId>
        <version>2.4.0</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.restdocs</groupId>
        <artifactId>spring-restdocs-mockmvc</artifactId>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.security</groupId>
        <artifactId>spring-security-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>${spring-cloud.version}</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

<repositories>
    <repository>
        <id>spring-snapshots</id>
        <name>Spring Snapshots</name>
        <url>https://repo.spring.io/snapshot</url>
        <snapshots>
            <enabled>true</enabled>
        </snapshots>
    </repository>
    <repository>
        <id>spring-milestones</id>
        <name>Spring Milestones</name>
        <url>https://repo.spring.io/milestone</url>
        <snapshots>
            <enabled>false</enabled>
        </snapshots>
    </repository>
</repositories>

从一些不太相关的数据中删除堆栈跟踪...

2018-03-21 15:07:20.481  INFO 26756 --- [  restartedMain] org.hibernate.Version                    : HHH000412: Hibernate Core {5.2.14.Final}
2018-03-21 15:07:20.483  INFO 26756 --- [  restartedMain] org.hibernate.cfg.Environment            : HHH000206: hibernate.properties not found
2018-03-21 15:07:20.539  INFO 26756 --- [  restartedMain] o.hibernate.annotations.common.Version   : HCANN000001: Hibernate Commons Annotations {5.0.1.Final}
    2018-03-21 15:07:20.930  INFO 26756 --- [  restartedMain] org.hibernate.dialect.Dialect            : HHH000400: Using dialect: org.hibernate.dialect.Oracle10gDialect
    2018-03-21 15:07:21.445  INFO 26756 --- [  restartedMain] o.h.e.j.e.i.LobCreatorBuilderImpl        : HHH000424: Disabling contextual LOB creation as createClob() method threw error : java.lang.reflect.InvocationTargetException

    java.lang.reflect.InvocationTargetException: null
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_162]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_162]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_162]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_162]
        at org.hibernate.engine.jdbc.env.internal.LobCreatorBuilderImpl.useContextualLobCreation(LobCreatorBuilderImpl.java:113) [hibernate-core-5.2.14.Final.jar:5.2.14.Final]
        at org.hibernate.engine.jdbc.env.internal.LobCreatorBuilderImpl.makeLobCreatorBuilder(LobCreatorBuilderImpl.java:54) [hibernate-core-5.2.14.Final.jar:5.2.14.Final]
        at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentImpl.<init>(JdbcEnvironmentImpl.java:271) [hibernate-core-5.2.14.Final.jar:5.2.14.Final]
        at ...
        at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210) [hibernate-core-5.2.14.Final.jar:5.2.14.Final]
        at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:51) [hibernate-core-5.2.14.Final.jar:5.2.14.Final]
        at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94) [hibernate-core-5.2.14.Final.jar:5.2.14.Final]
        at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:242) [hibernate-core-5.2.14.Final.jar:5.2.14.Final]
        at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210) [hibernate-core-5.2.14.Final.jar:5.2.14.Final]
        at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.handleTypes(MetadataBuildingProcess.java:352) [hibernate-core-5.2.14.Final.jar:5.2.14.Final]
        at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:111) [hibernate-core-5.2.14.Final.jar:5.2.14.Final]
        at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:861) [hibernate-core-5.2.14.Final.jar:5.2.14.Final]
        at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:888) [hibernate-core-5.2.14.Final.jar:5.2.14.Final]
        at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:57) [spring-orm-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        .
        .
        .
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:752) ~[spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:388) ~[spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) ~[spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1246) ~[spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1234) ~[spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
        at com.myservice.EqOrderServiceApplication.main(EqOrderServiceApplication.java:14) ~[classes/:na]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_162]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_162]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_162]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_162]
        at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-2.0.0.RELEASE.jar:2.0.0.RELEASE]
    Caused by: java.lang.AbstractMethodError: oracle.jdbc.driver.T4CConnection.createClob()Ljava/sql/Clob;
        ... 49 common frames omitted

    2018-03-21 15:07:22.361  INFO 26756 --- [  restartedMain] j.LocalContainerEntityManagerFactoryBean : Initialized JPA EntityManagerFactory for persistence unit 'default'
    2018-03-21 15:07:23.295  INFO 26756 --- [  restartedMain] s.c.a.AnnotationConfigApplicationContext : Refreshing FeignContext-dbe-order-detail: startup date [Wed Mar 21 15:07:23 EDT 2018]; parent: org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@1290d90c
    2018-03-21 15:07:23.316  INFO 26756 --- [  restartedMain] f.a.AutowiredAnnotationBeanPostProcessor : JSR-330 'javax.inject.Inject' annotation found and supported for autowiring
    2018-03-21 15:07:24.048  WARN 26756 --- [  restartedMain] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mainController' defined in file [<my path>\controller\MainController.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'orderService' defined in file [<my path>\service\OrderService.class]: Unsatisfied dependency expressed through constructor parameter 2; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.myservice.OtherServiceClient ': FactoryBean threw exception on object creation; nested exception is java.lang.IllegalStateException: PathVariable annotation was empty on param 0.
    2018-03-21 15:07:24.049  INFO 26756 --- [  restartedMain] s.c.a.AnnotationConfigApplicationContext : Closing FeignContext-dbe-order-detail: startup date [Wed Mar 21 15:07:23 EDT 2018]; parent: org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@1290d90c
    2018-03-21 15:07:24.051  INFO 26756 --- [  restartedMain] j.LocalContainerEntityManagerFactoryBean : Closing JPA EntityManagerFactory for persistence unit 'default'
    2018-03-21 15:07:24.053  WARN 26756 --- [  restartedMain] o.s.b.f.support.DisposableBeanAdapter    : Invocation of destroy method 'close' failed on bean with name 'eurekaRegistration': org.springframework.beans.factory.BeanCreationNotAllowedException: Error creating bean with name 'org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration$RefreshableEurekaClientConfiguration': Singleton bean creation not allowed while singletons of this factory are in destruction (Do not request a bean from a BeanFactory in a destroy method implementation!)
    2018-03-21 15:07:24.055  INFO 26756 --- [  restartedMain] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
    2018-03-21 15:07:24.077  INFO 26756 --- [  restartedMain] ConditionEvaluationReportLoggingListener : 

    Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
    2018-03-21 15:07:24.091 ERROR 26756 --- [  restartedMain] o.s.boot.SpringApplication               : Application run failed

    org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mainController' defined in file [<my path>\controller\MainController.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'orderService' defined in file [<my path>\service\OrderService.class]: Unsatisfied dependency expressed through constructor parameter 2; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.myservice.OtherServiceClient ': FactoryBean threw exception on object creation; nested exception is java.lang.IllegalStateException: PathVariable annotation was empty on param 0.
        at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:729) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:192) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1270) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        .
        .
        .
        at com.myservice.MyServiceApplication.main(MyServiceApplication.java:14) [classes/:na]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_162]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_162]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_162]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_162]
        at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.0.0.RELEASE.jar:2.0.0.RELEASE]
    Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'orderService' defined in file [<my path>\service\OrderService.class]: Unsatisfied dependency expressed through constructor parameter 2; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.myservice.OtherServiceClient ': FactoryBean threw exception on object creation; nested exception is java.lang.IllegalStateException: PathVariable annotation was empty on param 0.
        at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:729) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:192) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1270) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1127) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        .
        .
        .
        at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:815) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:721) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        ... 24 common frames omitted
    Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.myservice.OtherServiceClient ': FactoryBean threw exception on object creation; nested exception is java.lang.IllegalStateException: PathVariable annotation was empty on param 0.
        at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:168) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.getObjectFromFactoryBean(FactoryBeanRegistrySupport.java:101) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getObjectForBeanInstance(AbstractBeanFactory.java:1645) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.getObjectForBeanInstance(AbstractAutowireCapableBeanFactory.java:1178) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:258) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:251) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.addCandidateEntry(DefaultListableBeanFactory.java:1325) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1291) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1101) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1065) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:815) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:721) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        ... 38 common frames omitted
    Caused by: java.lang.IllegalStateException: PathVariable annotation was empty on param 0.
        at feign.Util.checkState(Util.java:128) ~[feign-core-9.5.1.jar:na]
        at org.springframework.cloud.openfeign.annotation.PathVariableParameterProcessor.processArgument(PathVariableParameterProcessor.java:51) ~[spring-cloud-openfeign-core-2.0.0.BUILD-20180321.114528-231.jar:2.0.0.BUILD-SNAPSHOT]
        at org.springframework.cloud.openfeign.support.SpringMvcContract.processAnnotationsOnParameter(SpringMvcContract.java:238) ~[spring-cloud-openfeign-core-2.0.0.BUILD-20180321.114528-231.jar:2.0.0.BUILD-SNAPSHOT]
        at feign.Contract$BaseContract.parseAndValidateMetadata(Contract.java:110) ~[feign-core-9.5.1.jar:na]
        at org.springframework.cloud.openfeign.support.SpringMvcContract.parseAndValidateMetadata(SpringMvcContract.java:133) ~[spring-cloud-openfeign-core-2.0.0.BUILD-20180321.114528-231.jar:2.0.0.BUILD-SNAPSHOT]
        at feign.Contract$BaseContract.parseAndValidatateMetadata(Contract.java:66) ~[feign-core-9.5.1.jar:na]
        at feign.ReflectiveFeign$ParseHandlersByName.apply(ReflectiveFeign.java:146) ~[feign-core-9.5.1.jar:na]
        at feign.ReflectiveFeign.newInstance(ReflectiveFeign.java:53) ~[feign-core-9.5.1.jar:na]
        at feign.Feign$Builder.target(Feign.java:218) ~[feign-core-9.5.1.jar:na]
        at org.springframework.cloud.openfeign.HystrixTargeter.target(HystrixTargeter.java:39) ~[spring-cloud-openfeign-core-2.0.0.BUILD-20180321.114528-231.jar:2.0.0.BUILD-SNAPSHOT]
        at org.springframework.cloud.openfeign.FeignClientFactoryBean.loadBalance(FeignClientFactoryBean.java:223) ~[spring-cloud-openfeign-core-2.0.0.BUILD-20180321.114528-231.jar:2.0.0.BUILD-SNAPSHOT]
        at org.springframework.cloud.openfeign.FeignClientFactoryBean.getObject(FeignClientFactoryBean.java:244) ~[spring-cloud-openfeign-core-2.0.0.BUILD-20180321.114528-231.jar:2.0.0.BUILD-SNAPSHOT]
        at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:161) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        ... 50 common frames omitted

    Disconnected from the target VM, address: '127.0.0.1:50881', transport: 'socket'

    Process finished with exit code 0    

此时我很困惑。

编辑:

更新，因此，为了进行更多调查，因为我有信心在开始 Feign 工作之前启动服务，我注释掉了对 Feign 客户端和 Feign 客户端本身的所有引用，除了应用程序类上的配置注释。我仍然在启动时看到对数据库驱动程序的引用，但应用程序确实运行了。这是我在启动时看到的异常，但应用程序启动时没有 Feign 交互。

2018-03-21 17:04:56.222  INFO 27424 --- [  restartedMain] o.h.e.j.e.i.LobCreatorBuilderImpl        : HHH000424: Disabling contextual LOB creation as createClob() method threw error : java.lang.reflect.InvocationTargetException

java.lang.reflect.InvocationTargetException: null
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_162]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:259) [hibernate-core-5.2.14.Final.jar:5.2.14.Final]
org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210) [hibernate-core-5.2.14.Final.jar:5.2.14.Final]
    at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:51) [hibernate-core-5.2.14.Final.jar:5.2.14.Final]
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94) [hibernate-core-5.2.14.Final.jar:5.2.14.Final]

Caused by: java.lang.AbstractMethodError: oracle.jdbc.driver.T4CConnection.createClob()Ljava/sql/Clob;
    ... 49 common frames omitted    

数据库驱动程序较旧，因此我可能会看到有关将其更新为 ojdbc8 驱动程序的信息...

Answer 1

之前feign client有问题。我猜你正在经历同样的事情，也许是因为你使用的是旧版本，但你应该做的是在你的 @PathVariable 注释中包含 pathVariable 名称，就像这样
@RequestMapping(value = "/hello/{name}", method = RequestMethod.GET)
String hello(@PathVariable(value = "name") 字符串名称);

详情请见here