md5加密
package com.fh.util; import java.security.MessageDigest; public class MD5 { public static String md5(String str) { try { MessageDigest md = MessageDigest.getInstance("MD5"); md.update(str.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)); } str = buf.toString(); } catch (Exception e) { e.printStackTrace(); } return str; } public static void main(String[] args) { System.out.println(md5("")); System.out.println(md5("mj1")); System.out.println(md5("123456")); System.out.println(md5("123456789123456789")); } }