Java Rest API 调用另一个 Rest 而不等待响应 - 在 JAX-RS 中

Question

我有一个案例要在我的项目中实现。下面是一个必须实现的示例休息服务

    @GET
    @Path("/test/{id}")
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public String getData(@PathParam("id") String id) {
        //Some processing to get value of String
        String result = doSomeProcessing();

        //I want to return this result to GUI and call one more rest api  
        // and end this process without waiting for response from second 
        //call

       new Thread(){
       //call second rest api
       }.start();

       return result;      

    }

使用新线程调用第二个休息 API 并返回结果而不等待第二个休息 API 的响应，这是一个好方法吗？我还研究了异步休息调用，但它并不完全符合我的要求。请指教。提前致谢

Answer 1

避免启动Thread直接。考虑ExecutorService而是如下所示:

@Singleton
@Path("foo")
public class FooResource {

    private ExecutorService executor;

    @PostConstruct
    public void onCreate() {

        // Creates a thread pool that reuses a fixed number 
        // of threads operating off a shared unbounded queue
        this.executor = Executors.newFixedThreadPool​(10);
    }

    @GET
    public Response getFoo() {

        String result = doSomeProcessing();

        // Submits a Runnable task for execution
        executor.submit(new LongRunningTask());

        return Response.ok(result).build();
    }

    @PreDestroy
    public void onDestroy() {

        // Initiates an orderly shutdown in which previously submitted 
        // tasks are executed, but no new tasks will be accepted.
        this.executor.shutdownNow();
    }
}

public class LongRunningTask implements Runnable {

    @Override
    public void run() {

        try {
            // Simulate a long running task
            // Don't do it in a real application
            Thread.sleep(10000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

探索Executors API 了解如何创建 ExecutorService 的详细信息实例。

<小时/>

在 Java SE 和 Servlet 容器中，您可以使用 ExecutorService适合您长时间运行的任务。在 Java EE 容器中，您应该使用 ManagedExecutorService相反:

@Resource
ManagedExecutorService executor;

一旦它成为容器管理的资源，您就不需要手动实例化和处置它。