ContentTypeTest.java

## ContentTypeTest.java
import java.io.IOException;
import java.lang.reflect.Field;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.spi.FileTypeDetector;
import java.util.HashMap;
import java.util.Map;
import sun.nio.fs.DefaultFileTypeDetector;
import sun.nio.fs.GnomeFileTypeDetector;

public class ContentTypeTest {

    public static void main(String[] argv) {
        Map<String,String> checks = new HashMap<>();
        checks.put("index.html", "text/html");
        checks.put("index.java", "text/x-java-source");

        Path path = Paths.get(".");
        System.out.println("current working directory: "+path.toAbsolutePath());
        int failCount = 0;
        try {
            FileTypeDetector fileTypeDetector = DefaultFileTypeDetector.create();
            System.out.println("DefaultFileTypeDetector class : " + fileTypeDetector.getClass().getCanonicalName());
            isGioAvailable(fileTypeDetector);
            for (Map.Entry<String,String> check : checks.entrySet()) {
                String expectedContentType = check.getValue();
                if(!checkContentType(check.getKey(), expectedContentType)){
                    failCount++;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        if (failCount > 0) {
            System.out.println("TEST FAIL!");
        } else {
            System.out.println("TEST PASS!");
        }
    }

    private static boolean checkContentType(String s, String expectedContentType) throws IOException {
        Path path = Paths.get(s);
        String filetype = Files.probeContentType(path);
        if (filetype == null || !filetype.equals(expectedContentType)) {
            System.out.println(path.toString() + " - file type is not "+expectedContentType+"; file type is - " + filetype);
            return false;
        } else {
            System.out.println(path.toString() + " - file type is "+expectedContentType);
            return true;
        }
    }

    private static void isGioAvailable(FileTypeDetector fileTypeDetector) throws NoSuchFieldException, IllegalAccessException {
        if (fileTypeDetector instanceof GnomeFileTypeDetector) {
            Field f = fileTypeDetector.getClass().getDeclaredField("gioAvailable"); //NoSuchFieldException
            f.setAccessible(true);
            Object gioAvailable = f.get(fileTypeDetector); //IllegalAccessException
            GnomeFileTypeDetector gnomeFileTypeDetector = (GnomeFileTypeDetector) fileTypeDetector;
            System.out.println("isGioAvailable: " + gioAvailable.toString());
        }
    }
}

## index.html
<html></html>

## index.java
class Index{}