如何使用AndroidStudio在AmazonRekognitionAWS中检测到Faces？

我已经尝试了很多方法，但是我无法成功。我尚未找到Android的任何源代码示例（关于rekognition）

在《开发人员指南》中的JAVA中有一个源代码，但是即使尝试了TT，我也无法实现该源代码

我尝试通过从外部存储（从仿真器）发送图像文件来检测人脸，但我不知道我做错了（我不擅长编码）这是我的代码

AmazonRekognitionClient amazonRekognitionClient;
Image getAmazonRekognitionImage;
DetectFacesRequest detectFaceRequest;
DetectFacesResult detectFaceResult;
File file = new File(Environment.getExternalStorageDirectory(),"sungyeol.jpg.jpg");

public void test_00(View view) {
 ByteBuffer imageBytes;
 try{
        InputStream inputStream = new FileInputStream(file.getAbsolutePath().toString());
        imageBytes = ByteBuffer.wrap(IOUtils.toByteArray(inputStream));
        Log.e("InputStream: ",""+inputStream);
        Log.e("imageBytes: ","");
        getAmazonRekognitionImage.withBytes(imageBytes);

        // Initialize the Amazon Cognito credentials provider
        CognitoCachingCredentialsProvider credentialsProvider = new CognitoCachingCredentialsProvider(
                getApplicationContext(),
                "us-east-2:.......", // Identity Pool ID
                Regions.US_EAST_2 // Region
        );

        //I want "ALL" attributes
        amazOnRekognitionClient= new AmazonRekognitionClient(credentialsProvider);

        detectFaceRequest = new DetectFacesRequest()
                .withAttributes(Attribute.ALL.toString())
                .withImage(getAmazonRekognitionImage);

        detectFaceResult = amazonRekognitionClient.detectFaces(detectFaceRequest);
        detectFaceResult.getFaceDetails();

    }
 catch(Exception ex){
   Log.e("Error on something:","Message:"+ex.getMessage());
 }

这是我的错误

02-04 09:30:07.268 29405-29405/? E/InputStream:: java.io.FileInputStream@a9b23e7
02-04 09:30:07.271 29405-29405/? E/Error on something:: Message:Attempt to invoke virtual method 'com.amazonaws.services.rekognition.model.Image com.amazonaws.services.rekognition.model.Image.withBytes(java.nio.ByteBuffer)' on a null object reference

什么是空对象引用？我尝试更改文件路径，但他说没有此类文件...，当我更改为该路径时，上面有错误。顺便说一句，我已经向用户询问了从Android中的模拟器访问文件夹的权限

请帮助我PS。对不起，我的英语不好

先感谢您。