I am uploading the mp3 file in my application, I have finished uploading the file and it works fine. I want to validate the file in server side, checking if the uploaded file is in a correct format(.mp3) or not. Client side validation works fine but I want to check it in server side as well, because there are changes to the upload the file by simply changing the extension.

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> I am using java servlet for uploading and I am having preprocessor to do validation before uploading.
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Anyone help me,
Thanks in advance.