java - 使嵌套的http请求java异步

Question

我正在为我的项目使用 play java(java play 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());
}

我犯了什么错误？如何一个接一个地发出嵌套请求？

我明白了

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

作为对我客户的回应

Answer 1

您必须使用 thenCompose 来链接多个 http 请求。这是一个工作示例:对于三个站点，我们将获取它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);
            });
    }