1 import java.security.MessageDigest;  2  3 /**  4  * md5加密 
     <功能详细描述>
        5  *  6  * @author wanglei  7  * @version [版本号, Feb 28, 2011]  8  * @see [相关类/方法]  9  * @since WihomeV100R001C02LGDM05 10 */ 11 public class Md5Util 12 {
   13     private static final String[] HEXDIGITS = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", 14             "e", "f"}; 15 16     private static final int NUM256 = 256; 17 18     private static final int NUM16 = 16; 19 20     /** 21      * 对字符串进行MD5加密 
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        22      * 23      * @param originString String 24      * @return String 25      * @see [类、类#方法、类#成员] 26 */ 27     public static String generatePassword(String originString) 28     {
   29         if (originString != null) 30         {
   31             try 32             {
   33                 MessageDigest md = MessageDigest.getInstance("MD5"); 34                 // 使用指定的字节数组对摘要进行最后更新，然后完成摘要计算 35                 byte[] results = md.digest(originString.getBytes()); 36                 // 将得到的字节数组变成字符串返回 37                 String resultString = byteArrayToHexString(results); 38                 return resultString; 39             } 40             catch (Exception ex) 41             {
   42                 ex.printStackTrace(); 43             } 44         } 45         return null; 46     } 47 48     private static String byteArrayToHexString(byte[] b) 49     {
   50         StringBuffer resultSb = new StringBuffer(); 51         for (int i = 0; i < b.length; i++) 52         {
   53             resultSb.append(byteToHexString(b[i])); 54         } 55         return resultSb.toString(); 56     } 57 58     /** 59      * 将一个字节转化成十六进制形式的字符串 
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         60      * 61      * @param b byte 62      * @return String 63      * @see [类、类#方法、类#成员] 64 */ 65     private static String byteToHexString(byte b) 66     {
   67         int n = b; 68         if (n < 0) 69         {
   70             n = NUM256 + n; 71         } 72         int d1 = n / NUM16; 73         int d2 = n % NUM16; 74         return HEXDIGITS[d1] + HEXDIGITS[d2]; 75     } 76 }