我可以在我的应用程序中REST API通过Feign但不能通过。RestTemplateSpring Boot
我的项目中有以下 Maven 模块。
rest-client-sample (aggregator `pom` for the following child `maven` modules)
eureka-server
greeting-service
greeting-client
greeting-service能够毫无问题地向 Eureka 注册自己，并且我能够通过客户端使用该服务Feign。但是，当我添加代码以通过RestTemplate. 请参阅下面的屏幕截图。
服务器启动时出错（问候客户端）
2017-11-24 16:47:40.094 INFO 12700 --- [ restartedMain] c.e.demo.GreetingClientApplication : No active profile set, falling back to default profiles: default
2017-11-24 16:47:40.121 INFO 12700 --- [ restartedMain] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@45219d5a: startup date [Fri Nov 24 16:47:40 EST 2017]; parent: org.springframework.context.annotation.AnnotationConfigApplicationContext@5a56ca37
2017-11-24 16:47:41.710 INFO 12700 --- [ restartedMain] o.s.cloud.context.scope.GenericScope : BeanFactory id=31702351-deb1-327c-b682-9744338df33c
2017-11-24 16:47:41.750 INFO 12700 --- [ restartedMain] f.a.AutowiredAnnotationBeanPostProcessor : JSR-330 'javax.inject.Inject' annotation found and supported for autowiring
2017-11-24 16:47:41.882 INFO 12700 --- [ restartedMain] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.cloud.netflix.metrics.MetricsInterceptorConfiguration$MetricsRestTemplateConfiguration' of type [org.springframework.cloud.netflix.metrics.MetricsInterceptorConfiguration$MetricsRestTemplateConfiguration$$EnhancerBySpringCGLIB$$99e7b7a4] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
2017-11-24 16:47:41.904 INFO 12700 --- [ restartedMain] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.cloud.autoconfigure.ConfigurationPropertiesRebinderAutoConfiguration' of type [org.springframework.cloud.autoconfigure.ConfigurationPropertiesRebinderAutoConfiguration$$EnhancerBySpringCGLIB$$83d51460] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
2017-11-24 16:47:43.188 INFO 12700 --- [ restartedMain] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 0 (http)
2017-11-24 16:47:43.217 INFO 12700 --- [ restartedMain] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2017-11-24 16:47:43.220 INFO 12700 --- [ restartedMain] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/8.5.23
2017-11-24 16:47:43.552 INFO 12700 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2017-11-24 16:47:43.553 INFO 12700 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 3431 ms
2017-11-24 16:47:44.187 INFO 12700 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean : Mapping servlet: 'dispatcherServlet' to [/]
2017-11-24 16:47:44.196 INFO 12700 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'metricsFilter' to: [/*]
2017-11-24 16:47:44.196 INFO 12700 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*]
2017-11-24 16:47:44.197 INFO 12700 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2017-11-24 16:47:44.197 INFO 12700 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2017-11-24 16:47:44.197 INFO 12700 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'requestContextFilter' to: [/*]
2017-11-24 16:47:44.197 INFO 12700 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'webRequestLoggingFilter' to: [/*]
2017-11-24 16:47:44.198 INFO 12700 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'applicationContextIdFilter' to: [/*]
2017-11-24 16:47:44.310 INFO 12700 --- [ restartedMain] s.c.a.AnnotationConfigApplicationContext : Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@58eedc97: startup date [Fri Nov 24 16:47:44 EST 2017]; parent: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@45219d5a
2017-11-24 16:47:44.414 INFO 12700 --- [ restartedMain] f.a.AutowiredAnnotationBeanPostProcessor : JSR-330 'javax.inject.Inject' annotation found and supported for autowiring
2017-11-24 16:47:44.940 WARN 12700 --- [ restartedMain] ationConfigEmbeddedWebApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'greetingClientApplication': Unsatisfied dependency expressed through field 'restTemplate'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'org.springframework.web.client.RestTemplate' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true), @org.springframework.cloud.client.loadbalancer.LoadBalanced()}
2017-11-24 16:47:44.941 INFO 12700 --- [ restartedMain] s.c.a.AnnotationConfigApplicationContext : Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@58eedc97: startup date [Fri Nov 24 16:47:44 EST 2017]; parent: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@45219d5a
2017-11-24 16:47:44.946 INFO 12700 --- [ restartedMain] o.apache.catalina.core.StandardService : Stopping service [Tomcat]
2017-11-24 16:47:44.988 INFO 12700 --- [ restartedMain] utoConfigurationReportLoggingInitializer :
Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled.
2017-11-24 16:47:45.450 ERROR 12700 --- [ restartedMain] o.s.b.d.LoggingFailureAnalysisReporter :
***************************
APPLICATION FAILED TO START
***************************
Description:
Field restTemplate in com.example.demo.GreetingClientApplication required a bean of type 'org.springframework.web.client.RestTemplate' that could not be found.
Action:
Consider defining a bean of type 'org.springframework.web.client.RestTemplate' in your configuration.
GreetingClientApplication.java
@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients
@RestController
public class GreetingClientApplication {
/* Consuming a service through Feign */
@Autowired
private GreetingClient greetingClient;
@RequestMapping("/greetWFeign")
public String greetWFeign() {
return greetingClient.greetWorld();
}
/* Consuming a service through RestTemplate */
@Autowired
@LoadBalanced
private RestTemplate restTemplate;
private final String restUrl = "http://GREETING-SERVICE";
@Bean
public RestTemplate restTemplate() {
return new RestTemplate();
}
@RequestMapping("/greetWRestTemplate")
public String greetWRestTemplate() {
return restTemplate.getForObject(restUrl, String.class);
}
public static void main(String[] args) {
SpringApplication.run(GreetingClientApplication.class, args);
}
}
问候客户端/pom.xml
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<artifactId>greeting-client</artifactId>
<packaging>jar</packaging>
<name>greeting-client</name>
<description>A Feign-based client application that consumes greeting service (Eureka Client)</description>
<parent>
<groupId>com.example.demo</groupId>
<artifactId>rest-client-sample</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-feign</artifactId>
</dependency>
</dependencies>
</project>
问候客户端/application.yml
spring:
application:
name: greeting-client
# Use 0 for random port
server:
port: 0
eureka:
client:
serviceUrl:
defaultZone: ${EUREKA_URI:http://localhost:8761/eureka}
instance:
preferIpAddress: true
问候服务/pom.xml
<modelVersion>4.0.0</modelVersion>
<artifactId>greeting-service</artifactId>
<packaging>jar</packaging>
<name>greeting-service</name>
<description>A REST-based greeting service (Eureka Client) which registers itself at the registry (Eureka Server)</description>
<parent>
<groupId>com.example.demo</groupId>
<artifactId>rest-client-sample</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
</dependencies>
</project>
问候服务/application.yml
spring:
application:
name: greeting-service
# Use 0 for random port
server:
port: 0
eureka:
client:
serviceUrl:
defaultZone: ${EUREKA_URI:http://localhost:8761/eureka}
instance:
preferIpAddress: true
问候服务应用程序.java
@SpringBootApplication
@EnableEurekaClient
@RestController
public class GreetingServiceApplication {
public static void main(String[] args) {
SpringApplication.run(GreetingServiceApplication.class, args);
}
@RequestMapping("/")
public String greetWorld() {
return "Hello World!";
}
}
尤里卡服务器/pom.xml
<modelVersion>4.0.0</modelVersion>
<artifactId>eureka-server</artifactId>
<packaging>jar</packaging>
<name>eureka-server</name>
<description>A service registry (Eureka Server)</description>
<parent>
<groupId>com.example.demo</groupId>
<artifactId>rest-client-sample</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka-server</artifactId>
</dependency>
</dependencies>
EurekaServerApplication.java
@SpringBootApplication
@EnableEurekaServer
public class EurekaServerApplication {
public static void main(String[] args) {
SpringApplication.run(EurekaServerApplication.class, args);
}
}
rest-client-sample/pom.xml（主聚合器 pom）
<modules>
<module>eureka-server</module>
<module>greeting-service</module>
<module>greeting-client</module>
</modules>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.8.RELEASE</version>
<relativePath />
</parent>
<!-- Adding all the common dependencies here -->
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-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>