MD5加密

MD5用的是哈希函数,在计算机网络中应用较多的不可逆加密算法有RSA公司发明的MD5算法和由美国国家技术标准研究所建议的安全散列算法SHA.

MD5可以查询MD5字典

public class MD5 {
   private static final Logger log = LoggerFactory.getLogger(MD5.class);
   private static char[] digits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
   private static Map<Character, Integer> rDigits = new HashMap<Character, Integer>(16);
   static {
      for (int i = 0; i < digits.length; ++i) {
         rDigits.put(digits[i], i);
      }
   }
   private static MD5 me = new MD5();
   private MessageDigest mHasher;
   private final ReentrantLock opLock = new ReentrantLock();

   private MD5() {
      try {
         this.mHasher = MessageDigest.getInstance("md5");
      } catch (Exception e) {
         throw new RuntimeException(e);
      }
   }

   public static MD5 getInstance() {
      return me;
   }

   public String getMD5String(String content) {
      return this.bytes2string(this.hash(content));
   }

   public String getMD5String(byte[] content) {
      return this.bytes2string(this.hash(content));
   }

   public byte[] getMD5Bytes(byte[] content) {
      return this.hash(content);
   }

   public byte[] hash(String str) {
      this.opLock.lock();
      try {
         byte[] bt = this.mHasher.digest(str.getBytes("utf-8"));
         if (null == bt || bt.length != 16) {
            throw new IllegalArgumentException("md5 need");
         }
         return bt;
      } catch (UnsupportedEncodingException e) {
         throw new RuntimeException("unsupported utf-8 encoding", e);
      } finally {
         this.opLock.unlock();
      }
   }

   public byte[] hash(byte[] data) {
      this.opLock.lock();
      try {
         byte[] bt = this.mHasher.digest(data);
         if (null == bt || bt.length != 16) {
            throw new IllegalArgumentException("md5 need");
         }
         return bt;
      } finally {
         this.opLock.unlock();
      }
   }

   public String bytes2string(byte[] bt) {
      int l = bt.length;
      char[] out = new char[l << 1];
      for (int i = 0, j = 0; i < l; i++) {
         out[j++] = digits[(0xF0 & bt[i]) >>> 4];
         out[j++] = digits[0x0F & bt[i]];
      }
      if (log.isDebugEnabled()) {
         log.debug("[hash]" + new String(out));
      }
      return new String(out);
   }

   public byte[] string2bytes(String str) {
      if (null == str) {
         throw new NullPointerException("Argument is not allowed empty");
      }
      if (str.length() != 32) {
         throw new IllegalArgumentException("String length must equals 32");
      }
      byte[] data = new byte[16];
      char[] chs = str.toCharArray();
      for (int i = 0; i < 16; ++i) {
         int h = rDigits.get(chs[i * 2]).intValue();
         int l = rDigits.get(chs[i * 2 + 1]).intValue();
         data[i] = (byte) ((h & 0x0F) << 4 | l & 0x0F);
      }
      return data;
   }

   public static void main(String[] args) {
      System.out.println(MD5.getInstance().getMD5String("ymapp20171017015316" +
            "{"MDL_CustomerInfoB":{"CustomerGUID":"A5D4C6FE-7D38-41AF-84E3-D4E3BAA74123","customerLoginName":"ling","password":"123","customerName":"\u51cc\u5b87","mailbox":"1000@qq.com","CustomerType":0,"CustomerLevel":11,"documentType":"","idNumber":"","legalRepresentative":"","unitOfficeAddress":"","unitSize":"","CorporateType":0,"unitOrganizationCode":"","address":"","zipCode":"","contactsPhoneCode":86,"contactsPhone":"","qqNumber":"","state":1,"ifVerified":0,"LastSetLevelUserGUID":"00000000-0000-0000-0000-000000000000","lastSetLevelTime":"2017-10-17 09:53:16","createTime":"2017-10-17 09:53:16"}}wqevds2135fs1sf"));
   }
}