try {
     // Bucket name
    String bucket = "examplebucket-1250000000";
    // The location identifier of the object in the bucket. The object key (Key) is the unique identifier of the object within the bucket. For details, see [Object Key](https://www.tencentcloud.com/document/product/436/13324?from_cn_redirect=1#.E5.AF.B9.E8.B1.A1.E9.94.AE).
    // Note: You do not need to encode the cosPath.
    String cosPath = "exampleobject";
    // Request HTTP method
    String method = "PUT";
    // Local file path
    final String localPath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).getAbsolutePath() + "/wechat.png";
    PresignedUrlRequest presignedUrlRequest = new PresignedUrlRequest(bucket
            , cosPath) {
        @Override
        public RequestBodySerializer getRequestBody()
                throws CosXmlClientException {
            // Used to calculate the signature URL for requests such as put that require a request body.
            return RequestBodySerializer.file(null, new File(localPath));
        }
    };
    presignedUrlRequest.setRequestMethod(method);
    // Sets the signature validity period to 60 seconds. Note that this is the signature validity period. You must ensure the key validity period yourself.
    presignedUrlRequest.setSignKeyTime(60);
    // Do not sign a specific header.
    // presignedUrlRequest.addNoSignHeader("XXX");
    // presignedUrlRequest.addNoSignHeader("Content-Length");
    // presignedUrlRequest.addNoSignHeader("Content-Type");
    // Obtain the pre-signed upload URL.
    String urlWithSign = cosXmlService.getPresignedURL(presignedUrlRequest);
    // Start upload.
    new Thread(new Runnable() {
        @Override
        public void run() {
          uploadFile(urlWithSign, localPath);
        }
    }).start();
} catch (CosXmlClientException e) {
    e.printStackTrace();
}

public void uploadFile(String targetUrl, String filePath) {
    int retryCount = 0;
    boolean success = false;

    while (!success && retryCount < 3) {
        HttpURLConnection connection = null;
        DataOutputStream outputStream = null;
        FileInputStream fileInputStream = null;

        try {
            fileInputStream = new FileInputStream(filePath);

            URL url = new URL(targetUrl);
            connection = (HttpURLConnection) url.openConnection();

            connection.setDoInput(true);
            connection.setDoOutput(true);
            connection.setUseCaches(false);

            connection.setRequestMethod("PUT");
            // Set the specific Content-Type for the network request, for example, image/jpeg.
            connection.setRequestProperty("Content-Type", "application/octet-stream");

            outputStream = new DataOutputStream(connection.getOutputStream());
            int bytesRead;
            byte[] buffer = new byte[8192];
            while ((bytesRead = fileInputStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, bytesRead);
            }

            outputStream.flush();

            if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
                if (connection.getResponseCode() >= 500) {
                    retryCount++;
                    continue;
                } else {
                    throw new RuntimeException("Server returned HTTP " + connection.getResponseCode()
                            + " " + connection.getResponseMessage());
                }
            }

            success = true;
        } catch (Exception e) {
            retryCount++;
        } finally {
            try {
                if (outputStream != null)
                    outputStream.close();
                if (fileInputStream != null)
                    fileInputStream.close();
            } catch (Exception ignored) {
            }

            if (connection != null)
                connection.disconnect();
        }
    }

    if (!success) {
        throw new RuntimeException("Failed to upload file after 3 attempts");
    }
}

try {
    // Bucket name
    String bucket = "examplebucket-1250000000"; 
    // The location identifier of the object in the bucket. The object key (Key) is the unique identifier of the object within the bucket. For details, see [Object Key](https://www.tencentcloud.com/document/product/436/13324?from_cn_redirect=1#.E5.AF.B9.E8.B1.A1.E9.94.AE).
    // Note: You do not need to encode the cosPath.
    String cosPath = "exampleobject";
    // Request HTTP method.
    String method = "GET"; 
    PresignedUrlRequest presignedUrlRequest = new PresignedUrlRequest(bucket
            , cosPath);
    presignedUrlRequest.setRequestMethod(method);

    // Sets the signature validity period to 60 seconds. Note that this is the signature validity period. You must ensure the key validity period yourself.
    presignedUrlRequest.setSignKeyTime(60);
    // Do not sign a specific header.
    // presignedUrlRequest.addNoSignHeader("XXX");
    // presignedUrlRequest.addNoSignHeader("Content-Length");
    // presignedUrlRequest.addNoSignHeader("Content-Type");

    // Obtain the pre-signed download URL.
    String urlWithSign = cosXmlService.getPresignedURL(presignedUrlRequest);
    // Start download.
    new Thread(new Runnable() {
        @Override
        public void run() {
          String localPath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).getAbsolutePath() + "/wechat.png";
          downloadFile(urlWithSign, localPath);
        }
    }).start();
} catch (CosXmlClientException e) {
    e.printStackTrace();
}

public void downloadFile(String fileUrl, String localPath) {
    int retryCount = 0;
    boolean success = false;
    while (!success && retryCount < 3) {
        HttpURLConnection connection = null;
        InputStream input = null;
        FileOutputStream output = null;
        try {
            URL url = new URL(fileUrl);
            connection = (HttpURLConnection) url.openConnection();
            connection.connect();
            if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
                if (connection.getResponseCode() >= 500) {
                    retryCount++;
                    continue;
                } else {
                    throw new RuntimeException("Server returned HTTP " + connection.getResponseCode()
                            + " " + connection.getResponseMessage());
                }
            }
            input = connection.getInputStream();
            output = new FileOutputStream(localPath);
            byte data[] = new byte[4096];
            int count;
            while ((count = input.read(data)) != -1) {
                output.write(data, 0, count);
            }
            success = true;
        } catch (Exception e) {
            retryCount++;
        } finally {
            try {
                if (output != null)
                    output.close();
                if (input != null)
                    input.close();
            } catch (Exception ignored) {
            }
            if (connection != null)
                connection.disconnect();
        }
    }
    if (!success) {
        throw new RuntimeException("Failed to download file after 3 attempts");
    }
}