Hystrix Javanica fallback not working in Spring Cloud 1.0

Question

I built a super simple Hystrix short circuit example based on @spencergibb feign-eureka spring cloud starter example. At first I thought I couldn't get the hystrix javanica default fallbackMethod to trigger due to feign.. now, removing feign, the hystrix default fallbackMethod still doesn't catch exceptions.

pom.xml

<parent>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-parent</artifactId>
    <version>1.0.0.RELEASE</version>
    <relativePath /> <!-- lookup parent from repository -->
</parent>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <java.version>1.8</java.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-eureka</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-hystrix</artifactId>
    </dependency>
    :
</dependencies>

Main file:

@SpringBootApplication
@EnableDiscoveryClient
@EnableHystrix
@RestController
public class HelloClientApplication {

  @Autowired
  HelloClientComponent helloClientComponent;

  @RequestMapping("/")
  public String hello() {
    return helloClientComponent.makeMultipleCalls();
  }

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

}

HelloClientComponent.java (created because I know javanica expects to be inside a spring managed component or service):

@Component
public class HelloClientComponent {

@Autowired
RestTemplate restTemplate;

public String makeMultipleCalls() {
    int cnt=20;
    StringBuilder sb = new StringBuilder();
    while (cnt-- > 0) {
        String response = theServerRequestRoot();
        sb.append(response).append("  ");
    }
    return sb.toString();
}

public String theServersRequestRootFallback() {
    System.out.println("BOMB!!!!!!");
    return "BOMB!!!!!!";
}

@HystrixCommand(fallbackMethod = "theServersRequestRootFallback", commandKey = "callToServers")
public String theServerRequestRoot() {
        ResponseEntity<String> result = restTemplate.getForEntity("http://HelloServer", String.class);
        System.out.println(result.getBody());
        return result.getBody();
}
}

I start 2 servers, one which always succeeds and responds, and the other will fail 30% of the time with a 500 error. When I curl this client (to '/') things go normally for the non-forced failure calls. Round robining works fine as well. When the second server does return the 500 error, the fallbackMethod does not get called and the curl to '/' ends and returns with an error.

Update with solution per Spencer and Dave's suggestions. Change to the following:

Main Application file:

@SpringBootApplication
@EnableDiscoveryClient
@EnableHystrix
@RestController
public class HelloClientApplication {

  @Autowired
  HelloClientComponent helloClientComponent;

@RequestMapping("/")
public String hello() {
    int cnt=20;
    StringBuilder sb = new StringBuilder();
    while (cnt-- > 0) {
        String response = helloClientComponent.theServerRequestRoot();     // call directly to @Component in order for @HystrixCommand to intercept via AOP
        sb.append(response).append("  ");
    }
    return sb.toString();
}

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

HelloClientComponent.java:

@Component
public class HelloClientComponent {

@Autowired
RestTemplate restTemplate;

public String theServersRequestRootFallback() {
    System.out.println("BOMB!!!!!!");
    return "BOMB!!!!!!";
}

@HystrixCommand(fallbackMethod = "theServersRequestRootFallback", commandKey = "callToServers")
public String theServerRequestRoot() {
        ResponseEntity<String> result = restTemplate.getForEntity("http://HelloServer", String.class);
        System.out.println(result.getBody());
        return result.getBody();
}
}

Answer 1

@HystrixCommand only works because Spring makes a proxy to call that method on. If you call the method from within the proxy it doesn't go through the interceptor. You need to call the @HystrixCommand from another @Component (or use AspectJ).