hex形式的byte 转 byte 如WORD 类型 0x277e 这时候是ascii 转int 39 *256+7e&0xFF
等于10110.根据传输的格式来进行，也可以转成String 再转回来，以下是根据理论走出的方法。（应该不是最优方法）
/**
* ascii to byte
*/
public static byte[] asciiToByte(byte[] data, int length){
if(length % 2 !=0){
return null;
}
byte[] bytes = new byte[length/2];
for(int i = 0,j = 0;i<length-1;i = i+2,j++){
bytes[j] = (byte)(isAscii(data[i],i)+isAscii(data[i+1],i+1));
}
return bytes;
}
//ascii 码转数字
public static int isAscii(byte b,int i){
int index = b&0xFF;
if(index-48<=9){
index = index - 48;
}else if(65<=index&&index<=70){
//
index = index - 65+10;
}else if(97<=index&&index<=102){
index = index - 97+10;
}
//word 类型转分高低位
if(i%2==0) {
index = index * 16;
}
return index ;
}
Byte转String 便于打印查看报文数据是否正确
public static String byteToHex(byte[] data){
StringBuilder str = new StringBuilder();
for (int i = 0; i < data.length; ++i) {
str.append(byteToHex(data[i]));
}
return str.toString();
}
public static String byteToHex(byte b){
return String.format("%02x ", b);
}
ByteToHex 转换
public static String byteToHex(byte b) {
String hex = Integer.toHexString(b & 0xFF);
if (hex.length() < 2) {
hex = "0" + hex;
}
return hex;
}
int 转word
public static byte[] getAsicc(int num){
byte[] bytes = new byte[2];
int a = num/256;
int b = num - a*256;
bytes[0] = (byte)a;
bytes[1] = (byte)b;
return bytes;
}