使用Java在AWS Lambda上調用Web服務

Question

我只是想從Java AWS Lambda函數調用外部Web服務。 為此，我無法使org.apache.http客戶端正常工作。 我有代碼：

public static String get(String get) throws ClientProtocolException, IOException{
    RequestConfig defaultRequestConfig = RequestConfig.custom().setExpectContinueEnabled(true).build();
    HttpGet httpGetRequest = new HttpGet(get);
    RequestConfig requestConfig = RequestConfig.copy(defaultRequestConfig).setSocketTimeout(5000).setConnectTimeout(5000).setConnectionRequestTimeout(5000).build();
    httpGetRequest.setConfig(requestConfig);

    CloseableHttpClient httpClient = HttpClientBuilder.create().build();
    HttpResponse httpResponse = httpClient.execute(httpGetRequest); <<<<<
    HttpEntity entity = httpResponse.getEntity();
    StringBuffer all = new StringBuffer();
    if (entity != null) {
        InputStream inputStream = entity.getContent();
        BufferedReader in = new BufferedReader(new InputStreamReader(new BufferedInputStream(inputStream)));
        String read;
        while ((read = in.readLine()) != null){
            all.append(read);
            all.append("\n");
        }
        httpClient.close();
    }
    return all.toString();
}

部署完成后，它將掛在HttpResponse httpResponse = httpClient.execute(httpGetRequest); <<<<< HttpResponse httpResponse = httpClient.execute(httpGetRequest); <<<<<以上。

我可以通過建立一個Socket連接來證明從lambda函數到Internet的連通性，例如Socket s = new Socket(InetAddress.getByName("bbc.co.uk"), 80); 這樣我就可以檢索數據

所以問題是，第一個在本地工作但在部署時無法工作的代碼片段出了什么問題？ 還是有一種從Java中的AWS lambda函數調用Web服務的首選方法（我進行了搜索，但找不到最佳實踐）？ 如果可以的話，我希望不必使用套接字來手工處理HTTP請求。

Answer 1

請嘗試使用Rest Template進行此呼叫。

Answer 2

這里的問題是Apache HttpClient的使用，它是一個大型庫。 切換到OkHttp解決了我的問題。

Answer 3

try {
    String url = "baseurl for AWS insatnce +8080/Testing/mailGenration/generate?msg=20;

    logger.log("Building HttpClient......");
    HttpClient client = HttpClientBuilder.create().build();
    HttpGet request = new HttpGet(url);

    HttpResponse response = client.execute(request);
    logger.log("Response Code : " + response.getStatusLine().getStatusCode());
} catch (Exception e) {
    logger.log("Exception in sendhttpclient:" + e);
}