springcloud-eureka,No instances available for user-service,but i find user-service at dashboard

Question

enter image description here

java.lang.IllegalStateException: No instances available for user-service
    at org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerClient.execute(RibbonLoadBalancerClient.java:119) ~[spring-cloud-netflix-ribbon-2.2.10.RELEASE.jar:2.2.10.RELEASE]
    at org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerClient.execute(RibbonLoadBalancerClient.java:99) ~[spring-cloud-netflix-ribbon-2.2.10.RELEASE.jar:2.2.10.RELEASE]
    at org.springframework.cloud.client.loadbalancer.LoadBalancerInterceptor.intercept(LoadBalancerInterceptor.java:56) ~[spring-cloud-commons-3.1.5.jar:3.1.5]
    at org.springframework.http.client.InterceptingClientHttpRequest$InterceptingRequestExecution.execute(InterceptingClientHttpRequest.java:93) ~[spring-web-5.3.29.jar:5.3.29]
    at org.springframework.http.client.InterceptingClientHttpRequest.executeInternal(InterceptingClientHttpRequest.java:77) ~[spring-web-5.3.29.jar:5.3.29]
    at org.springframework.http.client.AbstractBufferingClientHttpRequest.executeInternal(AbstractBufferingClientHttpRequest.java:48) ~[spring-web-5.3.29.jar:5.3.29]
    at org.springframework.http.client.AbstractClientHttpRequest.execute(AbstractClientHttpRequest.java:66) ~[spring-web-5.3.29.jar:5.3.29]
    at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:782) ~[spring-web-5.3.29.jar:5.3.29]
    at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:717) ~[spring-web-5.3.29.jar:5.3.29]
    at org.springframework.web.client.RestTemplate.getForEntity(RestTemplate.java:367) ~[spring-web-5.3.29.jar:5.3.29]
    at com.hwadee.manager.controller.QuestionController.getInfo(QuestionController.java:25) ~[classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_202]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_202]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_202]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_202]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-5.3.29.jar:5.3.29]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150) ~[spring-web-5.3.29.jar:5.3.29]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117) ~[spring-webmvc-5.3.29.jar:5.3.29]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895) ~[spring-webmvc-5.3.29.jar:5.3.29]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808) ~[spring-webmvc-5.3.29.jar:5.3.29]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.3.29.jar:5.3.29]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1072) ~[spring-webmvc-5.3.29.jar:5.3.29]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:965) ~[spring-webmvc-5.3.29.jar:5.3.29]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.29.jar:5.3.29]
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.3.29.jar:5.3.29]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:529) ~[tomcat-embed-core-9.0.79.jar:4.0.FR]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.3.29.jar:5.3.29]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:623) ~[tomcat-embed-core-9.0.79.jar:4.0.FR]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:209) ~[tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153) ~[tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51) ~[tomcat-embed-websocket-9.0.79.jar:9.0.79]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:178) ~[tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153) ~[tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.29.jar:5.3.29]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.29.jar:5.3.29]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:178) ~[tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153) ~[tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.29.jar:5.3.29]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.29.jar:5.3.29]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:178) ~[tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153) ~[tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.29.jar:5.3.29]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.29.jar:5.3.29]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:178) ~[tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153) ~[tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:167) ~[tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90) [tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:481) [tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:130) [tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93) [tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:390) [tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63) [tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:926) [tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1790) [tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52) [tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) [tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) [tomcat-embed-core-9.0.79.jar:9.0.79]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.79.jar:9.0.79]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_202]

This is my practice project architecture

enter image description here

@RestController
@RequestMapping("/question")
public class QuestionController {

    @Autowired
    private RestTemplate restTemplate;

    private static final String URL_PREFIX = "http://user-service";

    @RequestMapping("/list")
    public AjaxResult getInfo() {
//        String url = "http://localhost:8080/user/get/" + id;
        String url = URL_PREFIX + "/user/get/1";
        System.out.println(url);

        ResponseEntity<AjaxResult> forEntity = restTemplate.getForEntity(url, AjaxResult.class);
        AjaxResult body = forEntity.getBody();

        System.out.println(body);
        return AjaxResult.success("successful", body);
    }
}

The address of the request I initiated is http://localhost:8081:/question/list

If I initiate the above request, I will report an error

user-service is already configured in another service

@Configuration
public class RestTemplateConfig {
    @Bean
    @LoadBalanced
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }
}

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

it's user-service starter

@SpringBootApplication
@MapperScan("com.hwadee.manager.mapper")
@EnableEurekaClient
@EnableDiscoveryClient
public class UserApplication {
    public static void main(String[] args) {
        SpringApplication.run(UserApplication.class, args);
    }
}

After the service started, I saw it on the eureka dashboard, but when I called it, I found that it would make an error. I don't know where my problem occurred. If you need code from another place, please let me know. If you can't find the problem at the moment, you can also give me some suggestions. Thank you very much!