進度條 - SDK參考

進度條用於指示上傳或下載的進度。下面的代碼以ossClient.getObject方法為例，介紹如何使用進度條。

 
  static class GetObjectProgressListener implements ProgressListener {
          private long bytesRead = 0;
          private long totalBytes = -1;
          private boolean succeed = false;
  
          @Override
          public void progressChanged(ProgressEvent progressEvent) {
              long bytes = progressEvent.getBytes();
              ProgressEventType eventType = progressEvent.getEventType();
              switch (eventType) {
              case TRANSFER_STARTED_EVENT:
                  System.out.println("Start to download......");
                  break;
              case RESPONSE_CONTENT_LENGTH_EVENT:
                  this.totalBytes = bytes;
                  System.out.println(this.totalBytes + " bytes in total will be downloaded to a local file");
                  break;
              case RESPONSE_BYTE_TRANSFER_EVENT:
                  this.bytesRead += bytes;
                  if (this.totalBytes != -1) {
                      int percent = (int)(this.bytesRead * 100.0 / this.totalBytes);
                      System.out.println(bytes + " bytes have been read at this time, download progress: " +
                              percent + "%(" + this.bytesRead + "/" + this.totalBytes + ")");
                  } else {
                      System.out.println(bytes + " bytes have been read at this time, download ratio: unknown" +
                              "(" + this.bytesRead + "/...)");
                  }
                  break;
              case TRANSFER_COMPLETED_EVENT:
                  this.succeed = true;
                  System.out.println("Succeed to download, " + this.bytesRead + " bytes have been transferred in total");
                  break;
              case TRANSFER_FAILED_EVENT:
                  System.out.println("Failed to download, " + this.bytesRead + " bytes have been transferred");
                  break;
              default:
                  break;
              }
          }
  
          public boolean isSucceed() {
              return succeed;
          }
      }
  
  public static void main(String[] args) { 
      // Endpoint以杭州為例，其它Region請按實際情況填寫。
      String endpoint = "http://oss-cn-hangzhou.aliyuncs.com";
      // 阿里雲主帳號AccessKey擁有所有API的存取權限，風險很高。強烈建議您建立並使用RAM帳號進行API訪問或日常運維，請登入 https://ram.console.aliyun.com 建立RAM帳號。
      String accessKeyId = "<yourAccessKeyId>";
      String accessKeySecret = "<yourAccessKeySecret>";
      String bucketName = "<yourBucketName>";
      String objectName = "<yourObjectName>";
  
      OSSClient ossClient = new OSSClient(endpoint, accessKeyId, accessKeySecret);
  
      try {            
              // 帶進度條的下載。
              ossClient.getObject(new GetObjectRequest(bucketName, objectName).
                      <GetObjectRequest>withProgressListener(new GetObjectProgressListener()),
                      new File("<yourLocalFile>"));
      } catch (Exception e) {
          e.printStackTrace();
      }
      // 關閉OSSClient。
      ossClient.shutdown();
  }

ossClient.putObject、ossClient.getObject和ossClient.uploadPart方法支援進度條功能。ossClient.uploadFile和ossClient.downloadFile方法不支援進度條功能。

下載進度條的完整代碼請參見GitHub。