来作出嵌套的http请求的Java异步

Question

我使用可以玩Java为我的项目（Java游戏WS API）和

private CompletionStage<String> getAuthToken() { 
    WSRequest request = ws.url(URL); 
    WSRequest complexRequest = request.setHeader("X-API-Key", X_API_KEY) 
      .setHeader(CONTENT_TYPE, CONTENT_TYPE_VALUE) 
      .setHeader(AUTHORIZATION, CLIENT_DETAILS_BASE64_ENCODE); 
    CompletionStage<WSResponse> responsePromise = complexRequest.post(GRANT_TYPE + "=" 
      + PASSWORD + "&" + USERNAME + "=" + USERNAME + "&" + PASSWORD + "=" + PASSWORD); 
    return responsePromise.thenApply(response-> getAuthToken2().toString()); 
} 

private CompletionStage<String> getAuthToken2() { 
    WSRequest request = ws.url(URL); 
    WSRequest complexRequest = request.setHeader("X-API-Key", X_API_KEY) 
      .setHeader(CONTENT_TYPE, CONTENT_TYPE_VALUE) 
      .setHeader(AUTHORIZATION, CLIENT_DETAILS_BASE64_ENCODE); 
    CompletionStage<WSResponse> responsePromise = complexRequest.post(GRANT_TYPE + "=" 
      + PASSWORD + "&" + USERNAME + "=" + USERNAME + "&" + PASSWORD + "=" + PASSWORD); 
    return responsePromise.thenApply(response-> addIdentity(response.asJson().findValue("access_token").toString()).toString()); 
} 

什么是错误的，我在做什么？我如何一个接一个地嵌套请求？

我得到

java.util.concurrent.CompletableFuture@75c6e852[Not completed] 

为回应我的客户

Answer 1

你必须使用thenCompose把多个HTTP请求。这里是一个工作示例：对于三个站点，我们将获取他们的页面并将状态代码添加到JSON对象。最后，我们返回该对象。

public CompletionStage<Result> getSites() { 
    ObjectNode hosts = Json.newObject(); 
    return ws.url("https://www.facebook.com").get() 
      .thenCompose(res -> { 
       hosts.put("facebook", res.getStatus()); 
       return ws.url("https://www.google.com").get(); 
      }) 
      .thenCompose(res -> { 
       hosts.put("google", res.getStatus()); 
       return ws.url("https://www.twitter.com").get(); 
      }) 
      .thenApply(res -> { 
       hosts.put("twitter", res.getStatus()); 
       return ok(hosts); 
      }); 
    }