Question:
I have tried so many way but i can’t succeed. I haven’t found any source code examples for Android(about rekognition)
there’s a source code in JAVA in the Developer Guide but i cannot implement that even though I tried TT
I try to detect faces by sending an image file from an external storage(from the emulator)
I don’t know what i did wrong(I’m not good at coding)
Here is my code
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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()); } |
and here is my errors
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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 |
what is a null object reference?
i try to change the file path but he said no such file … and when I change to this path, there’s errors above.
by the way I’ve already asked a user for a permission to access a folder from Emulator in Android
please help me
PS. sorry for my bad English
Thank you in advance.
Answer:
Now I am ok with the issues. I have been through many many things <3 <3 <3.
Thank you
I’m Thai and I had to try harder to find the solutions because there’s lack of information in the particular language. Here are my solutions.
My solutions are:
0.There is an endpoint for setting for the Rekognition–>
http://docs.aws.amazon.com/general/latest/gr/rande.html#rekognition_region
1.On a “null object reference issue” I found that I have to create a new object first such as “Image image = new Image();” <– The “new” command creates an object instance in that class
2.After the above error, there are more errors (Errors on NetworkOnMainThreadException), so I tried everything until I found this page –>
https://docs.aws.amazon.com/cognito/latest/developerguide/getting-credentials.html the page said that …
Consequently, I looked up for more information about the AsyncTask and after that I created an AsyncTask class and then I move all my code about the initialize, the request, the response to the AsyncTask class. ตอนรันตอนท้ายๆน้ำตาจิไหล my code worked… TT and by the conclusion the sungyeol.jpg.jpg file worked
for example
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private void testTask(){ .... all code in the main thread particularly on the requests and responses from the services //print the response or the result //Log.e() makes the message in the android monitor red like an error Log.e("Response:", [responseparameter.toString()]); } //create the inherited class from the AsyncTask Class //(you can create within your activity class) class AsyncTaskRunner extends AsyncTask @Override public String doInBackground(String ... input){ testTask(); // call the testTask() method that i have created return null; // this override method must return String } } //I've created a button for running the task public void buttonTask(View view){ AsyncTaskRunner runner = new AsyncTaskRunner(); runner.execute(); } |
for more information about the AsyncTask:
https://developer.android.com/training/basics/network-ops/connecting.html#AsyncTask
http://www.compiletimeerror.com/2013/01/why-and-how-to-use-asynctask.html#.WJdkqVOLTIU
I hope these help 🙂