<dependencies>
  <!--openfein的依賴-->
  <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-openfeign</artifactId>
      <version>2.1.3.RELEASE</version>
  </dependency>
</dependencies>

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

@FeignClient(
        name = "demo-service",
        url = "http://localhost:8080/feign/server/",
        configuration = FeignInterceptor.class,
        fallback = TestService.DefaultFallback.class
)
public interface TestService {
    @RequestMapping(value = "/getError/{id}", method = RequestMethod.GET)
    public String getError(@RequestParam("id") Integer id);
    @RequestMapping(value = "/get1", method = RequestMethod.GET)
    public String get1();
    @RequestMapping(value = "/get2/{param}", method = RequestMethod.GET)
    public String get2(@RequestParam("param") String param);
    @RequestMapping(value = "/post1", method = RequestMethod.POST)
    public FeignDemo post1(@RequestBody FeignDemo demo);

@RestController
@RequestMapping("/feign/server")
public class FeignServerController {
    @GetMapping("/get1")
    public String get1() {
        return "get1";
    }
    @GetMapping("/get2/{para}")
    public String get2(@PathVariable("para") String para){
        return para;
    }
    @PostMapping("/post1")
    public FeignDemo  post1(@RequestBody FeignDemo demo) {
        return demo;
    }
}

public class FeignDemo {
    private String name;
    private Integer age;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
    @Override
    public String toString() {
        return "FeignDemo{" +
                "name='" + name + ''' +
                ", age=" + age +
                '}';
    }
}

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = {FeignApplication.class},webEnvironment = SpringBootTest.WebEnvironment.DEFINED_PORT)
@ActiveProfiles("dev,feign")
public class FeignClientTest {
    @Autowired
    private TestService testService;
    @Test
    public void testFallback(){
        testService.getError(1);
    }
    @Test
    public void testGet1(){
        System.out.println(testService.get1());
        System.out.println(testService.get2("abc"));
        System.out.printf("..");
        FeignDemo feignDemo = new FeignDemo();
        feignDemo.setName("name");
        feignDemo.setAge(1);
        System.out.println(testService.post1(feignDemo));
    }
@Component
    public class DefaultFallback implements TestService {
        @Override
        public String getError(@RequestParam("id") Integer id){
            return "";
        }
        @Override
        public String get1() {
            return null;
        }
        @Override
        public String get2(String param) {
            return null;
        }
        @Override
        public FeignDemo post1(FeignDemo demo) {
            return null;
        }
    }
}

<!--httpclient的依賴，因?yàn)檫x擇了使用httpclient-->
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
</dependency>
<dependency>
    <groupId>io.github.openfeign</groupId>
    <artifactId>feign-httpclient</artifactId>
    <version>10.4.0</version>
</dependency>

<dependency>
    <groupId>io.github.openfeign</groupId>
    <artifactId>feign-okhttp</artifactId>
    <version>10.2.0</version>
</dependency>

@Configuration
public class FooConfiguration {
    @Bean
    Logger.Level feignLoggerLevel() {
        return Logger.Level.FULL;
    }
}

public class TestConfiguration {
    @Bean
    Logger.Level feignLoggerLevel() {
        return Logger.Level.FULL;
    }
}

@FeignClient(
        name = "test-service",
        configuration = {FeignInterceptor2.class,TestConfiguration.class}
)

configureUsingConfiguration(context, builder); // 1
configureUsingProperties(properties.getConfig().get(properties.getDefaultConfig()),builder); //2
configureUsingProperties(properties.getConfig().get(this.contextId),builder);//3

class FeignInterceptor implements RequestInterceptor {
    @Override
    public void apply(RequestTemplate requestTemplate) {
        requestTemplate.header("user", "myuser1");
        requestTemplate.header("password", "mypassword");
    }
}

class FeignInterceptor1 implements RequestInterceptor {
    @Override
    public void apply(RequestTemplate requestTemplate) {
        requestTemplate.header("user1", "myuser1");
        requestTemplate.header("password1", "mypassword1");
    }
}

class FeignInterceptor2 implements RequestInterceptor {
    @Override
    public void apply(RequestTemplate requestTemplate) {
        requestTemplate.header("user2", "myuser2");
        requestTemplate.header("password2", "mypassword2");
    }
}

@FeignClient(
        name = "test-service",
        url = "http://localhost:8080/feign/server/",
        configuration = {FeignInterceptor.class,TestConfiguration.class},
        fallback = TestService.DefaultFallback.class
)