Gerando md5sum de um arquivo utilizando API do Java

Util.java

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.math.BigInteger;
import java.security.MessageDigest;

public class Util
{
	public static String md5File(File file) throws Exception
	{
		BufferedInputStream input = new BufferedInputStream(new FileInputStream(file));
		MessageDigest digest = MessageDigest.getInstance("MD5");

		byte[] buffer = new byte[1024];
		int len = 0;

		while((len=input.read(buffer))>0)
			digest.update(buffer, 0, len);

		byte[] md5sum = digest.digest();
		BigInteger sign = new BigInteger(1, md5sum);

		return sign.toString(16);
	}
}