微服务间调用Retrofit在Spring Cloud Alibaba中的使用

java -jar sentinel-dashboard-1.6.3.jar

/**
 * Created by macro on 2019/8/29.
 */
@RestController
@RequestMapping("/user")
public class UserController {
    private Logger LOGGER = LoggerFactory.getLogger(this.getClass());
    @Autowired
    private UserService userService;
    @PostMapping("/create")
    public CommonResult create(@RequestBody User user) {
        userService.create(user);
        return new CommonResult("操作成功", 200);
    }
    @GetMapping("/{id}")
    public CommonResult<User> getUser(@PathVariable Long id) {
        User user = userService.getUser(id);
        LOGGER.info("根据id获取用户信息，用户名称为：{}",user.getUsername());
        return new CommonResult<>(user);
    }
    @GetMapping("/getUserByIds")
    public CommonResult<List<User>> getUserByIds(@RequestParam List<Long> ids) {
        List<User> userList= userService.getUserByIds(ids);
        LOGGER.info("根据ids获取用户信息，用户列表为：{}",userList);
        return new CommonResult<>(userList);
    }
    @GetMapping("/getByUsername")
    public CommonResult<User> getByUsername(@RequestParam String username) {
        User user = userService.getByUsername(username);
        return new CommonResult<>(user);
    }
    @PostMapping("/update")
    public CommonResult update(@RequestBody User user) {
        userService.update(user);
        return new CommonResult("操作成功", 200);
    }
    @PostMapping("/delete/{id}")
    public CommonResult delete(@PathVariable Long id) {
        userService.delete(id);
        return new CommonResult("操作成功", 200);
    }
}

<dependencies>
    <!--Nacos注册中心依赖-->
     <dependency>
         <groupId>com.alibaba.cloud</groupId>
         <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
     </dependency>
    <!--Sentinel依赖-->
     <dependency>
         <groupId>com.alibaba.cloud</groupId>
         <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
     </dependency>
     <!--Retrofit依赖-->
     <dependency>
         <groupId>com.github.lianjiatech</groupId>
         <artifactId>retrofit-spring-boot-starter</artifactId>
         <version>2.2.18</version>
     </dependency>
 </dependencies>

server:
  port: 8402
spring:
  application:
    name: nacos-retrofit-service
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848 #配置Nacos地址
    sentinel:
      transport:
        dashboard: localhost:8080 #配置sentinel dashboard地址
        port: 8719
retrofit:
  log:
    # 启用日志打印
    enable: true
    # 日志打印拦截器
    logging-interceptor: com.github.lianjiatech.retrofit.spring.boot.interceptor.DefaultLoggingInterceptor
    # 全局日志打印级别
    global-log-level: info
    # 全局日志打印策略
    global-log-strategy: body
  # 熔断降级配置
  degrade:
    # 是否启用熔断降级
    enable: true
    # 熔断降级实现方式
    degrade-type: sentinel
    # 熔断资源名称解析器
    resource-name-parser: com.github.lianjiatech.retrofit.spring.boot.degrade.DefaultResourceNameParser

/**
 * Retrofit相关配置
 * Created by macro on 2022/1/26.
 */
@Configuration
public class RetrofitConfig {
    @Bean
    @Autowired
    public ServiceInstanceChooser serviceInstanceChooser(LoadBalancerClient loadBalancerClient) {
        return new SpringCloudServiceInstanceChooser(loadBalancerClient);
    }
}

/**
 * 定义Http接口，用于调用远程的User服务
 * Created by macro on 2019/9/5.
 */
@RetrofitClient(serviceId = "nacos-user-service", fallback = UserFallbackService.class)
public interface UserService {
    @POST("/user/create")
    CommonResult create(@Body User user);
    @GET("/user/{id}")
    CommonResult<User> getUser(@Path("id") Long id);
    @GET("/user/getByUsername")
    CommonResult<User> getByUsername(@Query("username") String username);
    @POST("/user/update")
    CommonResult update(@Body User user);
    @POST("/user/delete/{id}")
    CommonResult delete(@Path("id") Long id);
}

/**
 * 限流功能
 * Created by macro on 2019/11/7.
 */
@Api(tags = "RateLimitController",description = "限流功能")
@RestController
@RequestMapping("/rateLimit")
public class RateLimitController {
    @ApiOperation("按资源名称限流，需要指定限流处理逻辑")
    @GetMapping("/byResource")
    @SentinelResource(value = "byResource",blockHandler = "handleException")
    public CommonResult byResource() {
        return new CommonResult("按资源名称限流", 200);
    }
    @ApiOperation("按URL限流，有默认的限流处理逻辑")
    @GetMapping("/byUrl")
    @SentinelResource(value = "byUrl",blockHandler = "handleException")
    public CommonResult byUrl() {
        return new CommonResult("按url限流", 200);
    }
    @ApiOperation("自定义通用的限流处理逻辑")
    @GetMapping("/customBlockHandler")
    @SentinelResource(value = "customBlockHandler", blockHandler = "handleException",blockHandlerClass = CustomBlockHandler.class)
    public CommonResult blockHandler() {
        return new CommonResult("限流成功", 200);
    }
    public CommonResult handleException(BlockException exception){
        return new CommonResult(exception.getClass().getCanonicalName(),200);
    }
}

/**
 * 熔断降级
 * Created by macro on 2019/11/7.
 */
@Api(tags = "CircleBreakerController",description = "熔断降级")
@RestController
@RequestMapping("/breaker")
public class CircleBreakerController {
    private Logger LOGGER = LoggerFactory.getLogger(CircleBreakerController.class);
    @Autowired
    private UserService userService;
    @ApiOperation("熔断降级")
    @RequestMapping(value = "/fallback/{id}",method = RequestMethod.GET)
    @SentinelResource(value = "fallback",fallback = "handleFallback")
    public CommonResult fallback(@PathVariable Long id) {
        return userService.getUser(id);
    }
    @ApiOperation("忽略异常进行熔断降级")
    @RequestMapping(value = "/fallbackException/{id}",method = RequestMethod.GET)
    @SentinelResource(value = "fallbackException",fallback = "handleFallback2", exceptionsToIgnore = {NullPointerException.class})
    public CommonResult fallbackException(@PathVariable Long id) {
        if (id == 1) {
            throw new IndexOutOfBoundsException();
        } else if (id == 2) {
            throw new NullPointerException();
        }
        return userService.getUser(id);
    }
    public CommonResult handleFallback(Long id) {
        User defaultUser = new User(-1L, "defaultUser", "123456");
        return new CommonResult<>(defaultUser,"服务降级返回",200);
    }
    public CommonResult handleFallback2(@PathVariable Long id, Throwable e) {
        LOGGER.error("handleFallback2 id:{},throwable class:{}", id, e.getClass());
        User defaultUser = new User(-2L, "defaultUser2", "123456");
        return new CommonResult<>(defaultUser,"服务降级返回",200);
    }
}