java MD5加密类

import java.security.MessageDigest;import java.security.NoSuchAlgorithmException;public class Test {public static void main(String[] args) {Test test = new Test();System.out.println(test.encryption("123456"));}/**   *    * @param plainText   *            明文   * @return 32位密文   */public String encryption(String plainText) {String re_md5 = new String();try {MessageDigest md = MessageDigest.getInstance("MD5");md.update(plainText.getBytes());byte b[] = md.digest();int i;StringBuffer buf = new StringBuffer("");for (int offset = 0; offset < b.length; offset++) {i = b[offset];if (i < 0)i += 256;if (i < 16)buf.append("0");buf.append(Integer.toHexString(i));}re_md5 = buf.toString();} catch (NoSuchAlgorithmException e) {e.printStackTrace();}return re_md5;}}