eureka.instance.appname 与 spring.application.name 的区别

1，eureka.instance.appname

找到类 org.springframework.cloud.netflix.eureka.EurekaInstanceConfigBean.java，其中有段：

@Data
@ConfigurationProperties("eureka.instance")
public class EurekaInstanceConfigBean implements CloudEurekaInstanceConfig, EnvironmentAware {

    private static final String UNKNOWN = "unknown";

    /**
     * Get the name of the application to be registered with eureka.
     */
    private String appname = UNKNOWN;

可以看到，应用名称 就是在这里配置的；

2，spring.application.name

找到类 org.springframework.cloud.netflix.eureka.EurekaInstanceConfigBean，其中片段：

    @Override
    public void setEnvironment(Environment environment) {
        this.environment = environment;
        // set some defaults from the environment, but allow the defaults to use relaxed binding
        RelaxedPropertyResolver springPropertyResolver = new RelaxedPropertyResolver(this.environment, "spring.application.");
        String springAppName = springPropertyResolver.getProperty("name");
        if(StringUtils.hasText(springAppName)) {
            setAppname(springAppName);
            setVirtualHostName(springAppName);
            setSecureVirtualHostName(springAppName);
        }
    }

可以看到，这里是用 spring.application.name 配置的应用名称；

3，结论

从以上可以看到，spring.application.name 的优先级比 eureka.instance.appname 高，例如：

spring:
  application:
    name: jack
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
  instance:
    appname: client

两者都配置的时候，注册到Eureka Server上的 appname 是 jack