帶參數的Spring MVC異步控制器實現

Question

根據這篇博客，可以避免阻止HTTP請求線程等待更長的IO，使其異步。 在這里，單獨的線程負責在結果可用時返回結果。 基本實現如下

@RestController
public class RequestController {

  private final TaskService taskService;

  private final Logger logger = LoggerFactory.getLogger(this.getClass());


  @Autowired
  public RequestController(TaskService taskService) {
    this.taskService = taskService;
  }

  @RequestMapping(value = "/callable", method = RequestMethod.GET, produces = "text/html")
  public Callable<String> executeSlowTaskWithCallable() {
    logger.info("Request received");
    Callable<String> callable = taskService::execute;
    logger.info("Servlet thread released");

    return callable;
  }
  :
}

而不是“執行”（不帶參數並返回結果），我想創建Callable使用帶參數的方法並返回一些結果。 喜歡

Callable<String> callable = taskService.execute(request, headers);

怎么做到這一點？

Answer 1

只需使用lambda：

Callable<String> callable = () -> taskService.execute(request, headers);

像這樣：

@RestController
public class RequestController {

  private final Logger logger = LoggerFactory.getLogger(this.getClass());
  private final TaskService taskService;

  @Autowired
  public RequestController(TaskService taskService) {
    this.taskService = taskService;
  }

  @RequestMapping(value = "/callable", method = RequestMethod.GET, produces = "text/html")
  public Callable<String> executeSlowTaskWithCallable() {
    logger.info("Request received");
    Object request, headers = // initialize variables
    Callable<String> callable = () -> taskService.execute(request, headers);
    logger.info("Servlet thread released");

    return callable;
  }

}