How to check if a file is a PNG file using java

Question

I am going to automate png to jpg, all this is bullets, but I have a problem with detecting png files, now I use the file name and I check the ending if it matches ".png", but this does not work with files that are files png and do not end with ".png". any ideas?

Answer 1

u can try this

import javax.activation.MimetypesFileTypeMap;
import java.io.File;

class GetMimeType {
  public static void main(String args[]) {
    File f = new File(filePath);
    System.out.println("Mime Type of " + f.getName() + " is " +
                         new MimetypesFileTypeMap().getContentType(f));

}

or

try

public String getContentType(File file) throws IOException {
        return Files.probeContentType(file.getAbsolutePath());
}

Answer 2

You can check the file header.
See http://en.wikipedia.org/wiki/Portable_Network_Graphics#File_header .

Answer 3

Files.probeContentType(path) mime