How to reliably detect file types?

Question

Objective: given the file, determine whether it is of a given type (XML, JSON, Properties etc)

Consider the case of XML - Up until we ran into this issue, the follow

Answer 1

Apache Tika gives me the least amount of issues and is not platform specific unlike Java 7 : Files.probeContentType

import java.io.File;
import java.io.IOException;
import javax.activation.MimeType;
import org.apache.tika.Tika;

File inputFile = ...
String type = new Tika().detect(inputFile);
System.out.println(type);

For a xml file I got 'application/xml'

for a properties file I got 'text/plain'

You can however add a Detector to the new Tika()

    org.apache.tika
    tika-core
    1.xx