网摘的一个MD5Util

public class MD5Util { public final static String MD5(String s) { try { byte[] btInput = s.getBytes(); MessageDigest mdInst = MessageDigest.getInstance("MD5"); mdInst.update(btInput); byte[] md = mdInst.digest(); StringBuffer sb = new StringBuffer(); for (int i = 0; i < md.length; i++) { int val = ((int) md[i]) & 0xff; if (val < 16) sb.append("0"); sb.append(Integer.toHexString(val)); } return sb.toString(); } catch (Exception e) { return null; } } }