API调用

示例代码修改调用环境信息后可直接调用。以下以新建工程为例，介绍如何在您的应用中调用SDK进行请求签名。

1. 把API信息替换到HttpClientDemo.java中对应位置。
   1. 本示例以AK和SK保存在环境变量中为例，运行本示例前请先在本地环境中设置环境变量HUAWEICLOUD_SDK_AK和HUAWEICLOUD_SDK_SK。以Linux系统为例在本地将已获取的AK/SK设置为环境变量。
      1. 打开终端，输入以下命令打开环境变量配置文件。

         vi ~/.bashrc

      2. 设置环境变量，保存文件并退出编辑器。

         export HUAWEICLOUD_SDK_AK="已获取AK值" 
         export HUAWEICLOUD_SDK_SK="已获取SK值" 

      3. 输入以下命令使配置文件生效。

         source ~/.bashrc

   2. 把API信息和已设置的环境变量替换到HttpClientDemo.java中对应位置。
      

      HttpClientDemo中引用以下类，可在“获取SDK”包中的“src”文件下查看：

      • Constant：demo中用到的常量。
      • SSLCipherSuiteUtil：tls认证配置参数的工具类，比如配置客户端不校验证书。
      • UnsupportProtocolException：异常处理类。

      public class HttpClientDemo {
          private static final Logger  LOG GER = LoggerFactory.getLogger(HttpClientDemo.class);
          public static void main(String[] args) throws Exception {
              // Create a new request.
              Request httpClientRequest = new Request();
              try {
                  // Set the request parameters.
                  // AppKey, AppSecrect, Method and Url are required parameters.
                  // Directly writing AK/SK in code is risky. For security, encrypt your AK/SK and store them in the configuration file or environment variables.
                  // In this example, the AK/SK are stored in environment variables for identity authentication. 
                  // Before running this example, set environment variables HUAWEICLOUD_SDK_AK and HUAWEICLOUD_SDK_SK.
                  httpClientRequest.setKey(System.getenv("HUAWEICLOUD_SDK_AK"));
                  httpClientRequest.setSecret(System.getenv("HUAWEICLOUD_SDK_SK"));
                  httpClientRequest.setMethod("POST");
                  // Set a request URL in the format of https://{Endpoint}/{URI}.
                  httpClientRequest.setUrl("put your request url here");
                  httpClientRequest.addHeader("Content-Type", "text/plain");
                  // Set a body for http request.
                  httpClientRequest.setBody("put your request body here");
              } catch (Exception e) {
                  LOGGER.error(e.getMessage());
                  return;
              }
              CloseableHttpClient client = null;
              try {
                  // Sign the request.
                  HttpRequestBase signedRequest = Client.sign(httpClientRequest, Constant.SIGNATURE_ALGORITHM_SDK_HMAC_SHA256);
                  if (Constant.DO_VERIFY) {
                      // creat httpClient and verify ssl certificate
                      HostName.setUrlHostName(httpClientRequest.getHost());
                      client = (CloseableHttpClient) SSLCipherSuiteUtil.createHttpClientWithVerify(Constant.INTERNATIONAL_PROTOCOL);
                  } else {
                      // creat httpClient and do not verify ssl certificate
                      client = (CloseableHttpClient) SSLCipherSuiteUtil.createHttpClient(Constant.INTERNATIONAL_PROTOCOL);
                  }
                  HttpResponse response = client.execute(signedRequest);
                  // Print the body of the response.
                  HttpEntity resEntity = response.getEntity();
                  if (resEntity != null) {
                      LOGGER.info("Processing Body with name: {} and value: {}", System.getProperty("line.separator"),
                              EntityUtils.toString(resEntity, "UTF-8"));
                  }
              } catch (Exception e) {
                  LOGGER.error(e.getMessage());
              } finally {
                  if (client != null) {
                      client.close();
                  }
              }
          }
      }

2. 运行HttpClientDemo.java，对请求进行签名、访问API并打印结果。

   示例结果如下：

   [main] INFO com.huawei.apig.sdk.demo.HttpClientDemo - Print the authorization: [Authorization: SDK-HMAC-SHA256 Access=3afe***ba29, SignedHeaders=host;x-sdk-date, Signature=26b2***dbf6]
   [main] INFO com.huawei.apig.sdk.demo.HttpClientDemo - Print the status line of the response: HTTP/1.1 200 OK
   [main] INFO com.huawei.apig.sdk.demo.HttpClientDemo - Processing Header with name: Date and value: Fri, 26 Aug 2022 08:58:51 GMT
   [main] INFO com.huawei.apig.sdk.demo.HttpClientDemo - Processing Header with name: Content-Type and value: application/json
   [main] INFO com.huawei.apig.sdk.demo.HttpClientDemo - Processing Header with name: Transfer-Encoding and value: chunked
   [main] INFO com.huawei.apig.sdk.demo.HttpClientDemo - Processing Header with name: Connection and value: keep-alive
   [main] INFO com.huawei.apig.sdk.demo.HttpClientDemo - Processing Header with name: Server and value: api-gateway
   [main] INFO com.huawei.apig.sdk.demo.HttpClientDemo - Processing Header with name: X-Request-Id and value: 10955c5346b9512d23f3fd4c1bf2d181
   [main] INFO com.huawei.apig.sdk.demo.HttpClientDemo - Processing Body with name: 
    and value: {"200": "sdk success"}

   显示{"200": "sdk success"}，表示签名成功，API成功请求到后端。

   如果改变AK或SK的值，API网关将返回的错误信息error_msg。