JAVA MD5加密

package com.demo;

 

import java.security.MessageDigest;

 

public class MD5Util {

 

    private static final String ALGORITHM = "MD5";

 

    private static final char[] HEX_DIGITS = { '0', '1', '2', '3', '4', '5',

            '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };

 

    /**

     * encode string

     *

     * @param algorithm

     * @param str

     * @return String

     */

    public static String encode(String algorithm, String str) {

        if (str == null) {

            return null;

        }

        try {

            MessageDigest messageDigest = MessageDigest.getInstance(algorithm);

            messageDigest.update(str.getBytes());

            return getFormattedText(messageDigest.digest());

        } catch (Exception e) {

            throw new RuntimeException(e);

        }

 

    }

 

    /**

     * encode By MD5

     *

     * @param str

     * @return String

     */

    public static String getStringMD5String(String str) {

        if (str == null) {

            return null;

        }

        try {

            MessageDigest messageDigest = MessageDigest.getInstance(ALGORITHM);

            messageDigest.update(str.getBytes());

            return getFormattedText(messageDigest.digest());

        } catch (Exception e) {

            throw new RuntimeException(e);

        }

 

    }

 

    /**

     * Takes the raw bytes from the digest and formats them correct.

     *

     * @param bytes

     *            the raw bytes from the digest.

     * @return the formatted bytes.

     */

    private static String getFormattedText(byte[] bytes) {

        int len = bytes.length;

        StringBuilder buf = new StringBuilder(len * 2);

        // 把密文转换成十六进制的字符串形式

        for (int j = 0; j < len; j++) {         

            buf.append(HEX_DIGITS[(bytes[j] >> 4) & 0x0f]);

            buf.append(HEX_DIGITS[bytes[j] & 0x0f]);

        }

        return buf.toString();

    }

 

    public static void main(String[] args) {

        System.out.println(MD5Util.getStringMD5String("123"));

//      System.out.println("111111 MD5  :"

//              + EncoderHandler.encode("MD5", "111111"));

//      System.out.println("111111 SHA1 :"

//              + EncoderHandler.encode("SHA1", "111111"));

    }

 

}