生成预签名 URL

try {
     //存储桶名称
    String bucket = "examplebucket-1250000000";
    // 对象在存储桶中的位置标识符，对象键(Key)是对象在存储桶中的唯一标识。详情请参见 [对象键](https://cloud.tencent.com/document/product/436/13324#.E5.AF.B9.E8.B1.A1.E9.94.AE)
    // 注意：用户无需对 cosPath 进行编码操作
    String cosPath = "exampleobject";
    //请求 HTTP 方法
    String method = "PUT";
    PresignedUrlRequest presignedUrlRequest = new PresignedUrlRequest(bucket
            , cosPath) {
        @Override
        public RequestBodySerializer getRequestBody()
                throws CosXmlClientException {
            //用于计算 put 等需要带上 body 的请求的签名 URL
            return RequestBodySerializer.string("text/plain",
                    "this is test");
        }
    };
    presignedUrlRequest.setRequestMethod(method);
    // 设置签名有效期为 60s，注意这里是签名有效期，您需要自行保证密钥有效期
    presignedUrlRequest.setSignKeyTime(60);
    // 设置不签名 Host
    presignedUrlRequest.addNoSignHeader("Host");
    String urlWithSign = cosXmlService.getPresignedURL(presignedUrlRequest);
} catch (CosXmlClientException e) {
    e.printStackTrace();
}

try {
    //存储桶名称
    String bucket = "examplebucket-1250000000"; 
    // 对象在存储桶中的位置标识符，对象键(Key)是对象在存储桶中的唯一标识。详情请参见 [对象键](https://cloud.tencent.com/document/product/436/13324#.E5.AF.B9.E8.B1.A1.E9.94.AE)
    // 注意：用户无需对 cosPath 进行编码操作
    String cosPath = "exampleobject";
    //请求 HTTP 方法.
    String method = "GET"; 
    PresignedUrlRequest presignedUrlRequest = new PresignedUrlRequest(bucket
            , cosPath);
    presignedUrlRequest.setRequestMethod(method);

    // 设置签名有效期为 60s，注意这里是签名有效期，您需要自行保证密钥有效期
    presignedUrlRequest.setSignKeyTime(60);
    // 设置不签名 Host
    presignedUrlRequest.addNoSignHeader("Host");

    String urlWithSign = cosXmlService.getPresignedURL(presignedUrlRequest);

} catch (CosXmlClientException e) {
    e.printStackTrace();
}