EurekaClient

@Qualifier("eurekaClient")
@Autowired
private EurekaClient eurekaClient;

public String dataServiceUrlByEurekaClient() {
    InstanceInfo instance = eurekaClient.getNextServerFromEureka("spring-data-demo", false);
    return instance.getHomePageUrl();
}

DiscoveryClient

@Autowired
private DiscoveryClient discoveryClient;
public String dataServiceUrlByDiscoveryClient() {
    List list = discoveryClient.getInstances("spring-data-demo");
    if (list != null && list.size() > 0 ) {
        return String.valueOf(list.get(0).getUri());
    }
    return null;
}

RestTemplate

@Configuration
public class RestTemplateConfiguration {
    @Bean
    @LoadBalanced
    RestTemplate restTemplate(){
        return new RestTemplate();
    }
}
@Autowired
private RestTemplate restTemplate;

@GetMapping("/restTemplateTest")
public String restTemplateTest(){
        String str = restTemplate.getForObject("http://data-demo/demo/hello", String.class);
        return str;
 }