Java SHA256 digestSha256(String plain)

Description

digest Sha

License

Open Source License

Parameter

Parameter	Description
plain	plain text

Exception

Parameter	Description
RuntimeException	if SHA-256 algorithm does not exist

Return

SHA-256 hash (in hex)

Declaration

public static final String digestSha256(String plain) 

Method Source Code

//package com.java2s;
/**/*from  ww  w .  j a va  2  s. c  o  m*/
 * Heatmap Framework - Core
 *
 * Copyright (C) 2013   Martin Becker
 *                   becker@informatik.uni-wuerzburg.de
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/gpl-3.0.html>.
 */

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class Main {
    /**
     * @param plain plain text
     * 
     * @return SHA-256 hash (in hex)
     * 
     * @throws RuntimeException if SHA-256 algorithm does not exist
     */
    public static final String digestSha256(String plain) {
        try {
            return digest(plain, "SHA-256");
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * @param plain plain text
     * @param algorithm digest algorithm
     * 
     * @return digest in hex according to the given algorithm
     * 
     * @throws NoSuchAlgorithmException if the digest algorithm does not exist
     */
    public static String digest(String plain, String algorithm) throws NoSuchAlgorithmException {

        MessageDigest messageDigest;
        messageDigest = MessageDigest.getInstance(algorithm);

        byte[] bytes = toByteArray(plain);
        byte[] digestedBytes = messageDigest.digest(bytes);

        String hex = toHexString(digestedBytes);

        return hex;
    }

    /**
     * @param plain plain text
     * 
     * @return byte representation of the text using UTF-8 character set
     * 
     * @throws RuntimeException if encoding UTF-8 is not supported
     */
    public static final byte[] toByteArray(String plain) {
        try {
            return plain.getBytes("UTF-8");
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * @param bytes byte array
     * 
     * @return hex representation
     */
    public static final String toHexString(byte[] bytes) {
        StringBuffer stringBuffer = new StringBuffer();
        for (byte b : bytes) {

            String part = Integer.toHexString((int) (b & 0xff));

            if (part.length() < 2) {
                stringBuffer.append(0);
            }

            stringBuffer.append(part);
        }
        return stringBuffer.toString();
    }
}

Related

1. digestSHA256(byte[] input)
2. digestSha256(String value)
3. getSHA256(String input)
4. sha256()
5. sha256(byte[] bytes)