从Java字节中提取半字节

Question

Hex:[0A][52][08][01][01][01][00][CD][21][02][59]


0      [0A]
1      [52]         Packettype    = TEMP_HUM
2      [08]         subtype       = TH8 - 
3      [01]         Sequence nbr  = 1
4/5    [01][01]     ID            = 257
6/7    [00][CD]     Temperature   = 20.5 °C
8      [21]         Humidity      = 33
9      [02]         Status        = Dry
10     [5] *nibble           Signal level  = 5
11     [9] *nibble           Battery       = OK

所以我通过串口获得了11个字节（Hex）。 我将所有字节分配给一个字节数组，以便以后可以使用它们。

我有两个问题：

1]我如何结合4＆amp;用Java重新组合5个字节（我假设在INT中）？ 2]如何提取最后一个字节的10和11或高和低半字节？

[来自下面的评论] 示例字节：高[0110]低                lowNibble = yourbyte＆amp;为0x0F;                01010110＆amp; 0x0f（00001111）= 00000110

           highNibble = yourByte >>>> 4
           01010110 >>> 4 = 00000101


          IF you use this Example Byte: High[1101][0110]Low
          highNibble = yourByte >>> 4
          11010110 >>> 4 = 00000101
          Because >>> removes the signed bit.

Answer 1

1）这取决于字节顺序。它可以是(b[4] << 8) | b[5]或(b[5] << 8) | b[4]

2）lowNibble = yourByte & 0x0f; highNibble = (yourByte >> 4) & 0x0f;

你也可以这样做：lowNibble = yourByte & 0x0f; highNibble = yourByte >>> 4;

无符号移位（>>>）用零填充高位，无论符号如何。