1 import java.security.MessageDigest; 2 import java.security.NoSuchAlgorithmException; 3  4 public class MD5 { 5     public static final String MD5CODE = ""; 6  7     private static MessageDigest messageDigest = null; 8  9     public static String Encode(final String Source) {10         return Encode(Source + MD5CODE, null);11     }12 13     public static String Encode(final String Source, final String charset) {14         if (Source == null)15             return null;16         if (messageDigest == null) {17             try {18                 messageDigest = MessageDigest.getInstance("MD5");19             } catch (NoSuchAlgorithmException e) {20                 return null;21             }22         }23         if (charset == null || charset.trim().length() <= 0){24             messageDigest.update(Source.getBytes());25             }else {26             try {27                 messageDigest.update(Source.getBytes(charset));28             } catch (Exception e) {29                 messageDigest.update(Source.getBytes());30             }31         }32         byte[] digesta = messageDigest.digest();33         return Bytes2Hex(digesta);34     }35 36     public static byte[] EncodeBytes(byte[] Source) {37         if (messageDigest == null) {38             try {39                 messageDigest = MessageDigest.getInstance("MD5");40             } catch (NoSuchAlgorithmException e) {41                 return null;42             }43         }44         messageDigest.update(Source);45         byte[] ret = messageDigest.digest();46         return ret;47     }48 49     public static String Bytes2Hex(final byte[] Source) {50         String hs = "";51         String stmp = "";52         for (int n = 0; n < Source.length; n++) {53             stmp = (java.lang.Integer.toHexString(Source[n] & 0xFF));54             if (stmp.length() == 1)55                 hs = hs + "0" + stmp;56             else57                 hs = hs + stmp;58         }59         return hs;60     }61 62     public static void main(String args[]) {63 64         String str = "123456";65         String encode = MD5.Encode(str);66         String encode1 = MD5.Encode(str);67         String encode2 = MD5.Encode(str);68         System.out.println("MD5.encode 123456="+encode+"---"+encode1+"---"+encode2);69     70     }71 }