android加密算法之MD5 方法1fun getMD5A(str: String): String? { return try { val md: MessageDigest = MessageDigest.getInstance("MD5")//生成一个MD5加密计算摘要 md.update(str.toByteArray()) //计算md5函数 var md5Str: String = BigInteger(1, md.digest()).toString(16) if (md5Str.length < 32) { md5Str = "0$md5Str" } md5Str } catch (e: Exception) { throw Exception("MD5加密出现错误") } }方法2，修改hexDigits可生所不同的字符串：例如：charArrayOf('5','2','0','1','3','1','4','7','8','9','a','b','c','d','e','f')fun getMD5B(str: String): String? { val hexDigits = charArrayOf('0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f') return try { val mdInst = MessageDigest.getInstance("MD5") mdInst.update(str.toByteArray()) val md = mdInst.digest() val j = md.size val str = CharArray(j * 2) var k = 0 for (i in 0 until j) { val byte0 = md[i] str[k++] = hexDigits[byte0.toInt().ushr(4) and 0xf] str[k++] = hexDigits[byte0.toInt().and(0xf)] } String(str) } catch (e: java.lang.Exception) { e.printStackTrace() null } }