자바 코드

Question

다음은 제 16 진수 문자열

String str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

이며,이 내 CRC이다 : 위의 문자열에 추가됩니다 A228. I 출력 A228 등

다항식 사용이

누군가가 나에게 CRC16를 계산하는 코드를 제공 할 수

다음

이 내 자바 코드

String str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

    byte arr[] = toByteArray(str); 


     long polynomial = 0xA001; 
     long CRC = 0xFFFF; 

     for (byte b : arr) 
     { 
      CRC ^= b; 
      for (int i = 8; i != 0; i--) 
      { 
       if ((CRC & 0x0001) != 0) 
       { 
        CRC = (CRC >> 1)^polynomial; 
       } 
       else 
       { 
        CRC >>= 1; 
       } 
      } 
     } 



     System.out.println(CRC); 

}

0xA001

이다 싶어

출력이 -56289로 표시됩니다.

Answer 1

올바른 데이터를 입력하고 결과 CRC를 올바르게 표시해야한다는 점을 제외하고 코드는 대부분 괜찮으며 아래 메시지와 함께 해당 메시지에 대해 0xa228을 생성합니다 (아래 수정 포함).

올바른 데이터를 입력하려면 먼저 해당 16 진수 문자열을 많은 이진수 바이트의 절반으로 변환해야합니다. CRC 루틴에 을 부여하면이됩니다.

둘째, 십진수가 아닌 16 진수로 결과를 표시하십시오.

세 번째로 byte에 서명되어 있으므로 부호 확장을 피하기 위해 CRC ^= b & 0xff;을 사용하십시오.