TIL-Lab49/Using Apache Tika for file type validation

apache-tika-basics.md

We recently had a security team ask us to validate that the file being uploaded was indeed a plain text file. To do this, we decided to use Apache Tika.

The code itself is fairly straightforward:

import org.apache.tika.config.TikaConfig;
import org.apache.tika.exception.TikaException;
import org.apache.tika.io.TikaInputStream;
import org.apache.tika.mime.MediaType;
import org.apache.tika.metadata.MetaData;

// assuming we get the file as an inputStream using a Jersey endpoint

TikaConfig tika = new TikaConfig;
MediaType mimeType = tika.getDetector().detect(TikaInputStream.get(inputStream), new Metadata());

if(!MediaType.TEXT_PLAIN.equals(mineType)){
  // invalid file type
} else {
  // valid file type
}