Java将字符串十六进制值转换为byte []，重新创建了obj-c功能 [英] Java convert string hex values to byte[], recreating this obj-c functionality
问题描述
我正在制作一个与特定的蓝牙低功耗设备通信的应用程序.它需要特定的握手，并且在iOS的Objective-C中都可以正常使用，但是，在Java
I am making an app that communicates with a specific Bluetooth Low Energy device. It requires a specific handshake and this is all working perfectly in Objective-C for iOS, however, I am having trouble recreating this functionality in Java
任何想法都值得赞赏！
工作Objective-C代码:
uint8_t bytes[] = {0x04,0x08,0x0F,0x66,0x99,0x41,0x52,0x43,0x55,0xAA};
NSData *data = [NSData dataWithBytes:bytes length:sizeof(bytes)];
[_btDevice writeValue:data forCharacteristic:_dataCommsCharacteristic type:CBCharacteristicWriteWithResponse];
到目前为止，对于android，我具有以下等效项:
So far for android I have the following as an equivalent:
byte[] handshake = {0x04,0x08,0x0F,0x66,(byte)0x99,0x41,0x52,0x43,0x55,(byte)0xAA};
characteristic.setValue(handshake);
boolean writeStatus = gatt.writeCharacteristic(characteristic);
Log.d(TAG,"Handshake sent: " + writeStatus);
如前所述，iOS运作良好，但Java中的等效功能却未从设备获得任何响应，这使我认为发送的数据有误/无法识别
As mentioned, iOS works great, but the equivalent in Java is getting no response from the device, leading me to think that the data being sent is wrong/not recognised
更新 因此，经过大量的努力，我对我认为！"发生的事情有了更多的了解.
UPDATE So, after plenty of wrestling with this I have a little more insight into what is going on 'I think!'
就像下面提到的可怕袋熊一样，一个int的最大值是127，所以0x99和0xAA数组中的2个值当然不在此范围内
As Scary Wombat mentioned below the maximum value of an int is 127 so the 2 values in the array of 0x99 and 0xAA are of course out of this range
以下是我对这些值所处的位置:
The below is where I am at with the values:
byte bytes[] = {0x04,0x08,0x0F,0x66,(byte)0x99,0x41,0x52,0x43,0x55,(byte)0xAA};
Log.d(TAG, Arrays.toString(bytes));
生产
[4, 8, 15, 102, -103, 65, 82, 67, 85, -86]
但是期望值必须是
[4, 8, 15, 102, 153, 65, 82, 67, 85, 170]
我尝试过隐式转换这些麻烦的字节，还尝试了以下方法:
I have tried casting these troublesome bytes implicitly and also tried the below below:
byte bytes[] = {0x04,0x08,0x0F,0x66,(byte)(0x99 & 0xFF),0x41,0x52,0x43,0x55,(byte)(0xAA & 0xFF)};
但是，数组中的结果值始终相同.
However the resulting values in the array are always the same.
请帮助！！！ :)
更新2
经过一天的挖掘，看来尽管这些值记录有误，但蓝牙设备感知的值仍应正确，因此我修改了此问题，并继续进行
After a day of digging it appears that although the values are logging incorrectly the values perceived by the Bluetooth device SHOULD still be correct, so I have modified this question and continuing over here
推荐答案
String handshakeString = "0x04,0x08,0x0F,0x66,0x99,0x41,0x52,0x43,0x55,0xAA";
byte[] value = handshakeString.getBytes();
也会考虑,，因此会创建很多bytes，并且不会在您的c代码中包含相同的byte AS.
will also account the , and so creates to much bytesand will not geht the same bytes AS in your c code.
尝试直接使用byte[].
byte[] value=new byte[]{0x04,0x08,0x0F,0x66,0x99,0x41,0x52,0x43,0x55,0xAA};
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