Siba/src/org/dclermonte/siba/model/SibaUtils.java

package org.dclermonte.siba.model;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.IOException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import org.apache.commons.compress.utils.IOUtils;

public class SibaUtils
{
	/**
	 *
	 * @param choosenFile
	 * @return
	 * @throws IOException
	 */
	public static String loadMD5Sum(final File choosenFile) throws IOException
	{
		String result = "";

		if (choosenFile.exists() && (choosenFile.length() > 32))
		{
			FileReader fileReader = new FileReader(choosenFile);
			char[] md5 = new char[32];
			byte[] md5byte = new byte[32];
			for (int index = 0; index < 32; index++)
			{
				md5[index] = (char) fileReader.read();
				md5byte[index] = (byte) md5[index];
				result = result + md5[index];
			}
			fileReader.close();
		}

		//
		//
		return result;
	}

	/**
	 * This method calculate the MD5 itself.
	 *
	 * @param input
	 * @return
	 * @throws IOException
	 * @throws NoSuchAlgorithmException
	 */
	public static String md5(final File input) throws IOException, NoSuchAlgorithmException
	{
		String result;
		StringBuilder hashString = new StringBuilder();
		FileInputStream fileInputStream = null;
		try
		{
			byte[] byteInput = new byte[(int) input.length()];
			fileInputStream = new FileInputStream(input);
			for (int index1 = 0; index1 < input.length(); index1++)
			{
				byteInput[index1] = (byte) fileInputStream.read();
			}
			byte[] hash = null;
			MessageDigest messageDigest = MessageDigest.getInstance("MD5");
			hash = messageDigest.digest(byteInput);

			for (int index = 0; index < hash.length; index++)
			{
				String hex = Integer.toHexString(hash[index]);
				if (hex.length() == 1)
				{
					hashString.append('0');
					hashString.append(hex.charAt(hex.length() - 1));
				}
				else
				{
					hashString.append(hex.substring(hex.length() - 2));
				}
			}
			fileInputStream.close();

			result = hashString.toString();
		}
		finally
		{
			IOUtils.closeQuietly(fileInputStream);
		}
		//
		return result;
	}
}