package de.torui.coflsky.utils;

import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.security.MessageDigest;

public class FileUtils {

    public static byte[] createChecksum(File file) throws Exception {
        InputStream fis =  new FileInputStream(file);

        byte[] buffer = new byte[1024];
        MessageDigest complete = MessageDigest.getInstance("MD5");
        int numRead;

        do {
            numRead = fis.read(buffer);
            if (numRead > 0) {
                complete.update(buffer, 0, numRead);
            }
        } while (numRead != -1);

        fis.close();
        return complete.digest();
    }


    public static String getMD5Checksum(File file) throws Exception {
        byte[] b = createChecksum(file);
        String result = "";

        for (int i=0; i < b.length; i++) {
            result += Integer.toString( ( b[i] & 0xff ) + 0x100, 16).substring( 1 );
        }
        return result;
    }


}