不得不说AI是最擅长处理类似的需求的，比方16进制字符串转换为byte数组，字符串中含有0xff的字符串。
原来写的代码始终转不了带ff的十六进制字符串，然后用文言一心一试，居然一次就过了。
下面是代码：
代码语言：javascript复制public static byte[] hexStringToByteArray(String hexString) {
int len = hexString.length();
byte[] data = new byte[len / 2];
for (int i = 0; i < len; i = 2) {
data[i / 2] = (byte) ((Character.digit(hexString.charAt(i), 16) << 4)
Character.digit(hexString.charAt(i 1), 16));
}
return data;
}原来写的转换方法失效，原因是处理0xff失效了，代码如下：
代码语言：javascript复制/**
* 十六进制转byte字节
* @param hexString
* @return
*/
public static byte hexToByte(String hexString) {
int firstDigit = toDigit(hexString.charAt(0));
int secondDigit = toDigit(hexString.charAt(1));
if (firstDigit == 0 && secondDigit == 0){
return 0x2E;//-
}
if(firstDigit > 7){
return 0x2E;//.
}
return (byte) ((firstDigit << 4) secondDigit);
}
private static int toDigit(char hexChar) {
int digit = Character.digit(hexChar, 16);
if(digit == -1) {
throw new IllegalArgumentException(
"Invalid Hexadecimal Character: " hexChar);
}
return digit;
}
/**
* 字节数组转十六进制
* @param byteArray
* @return
*/
public static String encodeHexString(byte[] byteArray) {
if(byteArray==null){
return "";
}
StringBuffer hexStringBuffer = new StringBuffer();
for (int i = 0; i < byteArray.length; i ) {
hexStringBuffer.append(byteToHex(byteArray[i]));
}
return hexStringBuffer.toString().toUpperCase();
}
/**
* 十六进制转字节数组
* @param hexString
* @return
*/
public static byte[] decodeHexString(String hexString) {
if (hexString == null){
return new byte[1];
}
if (hexString.length() % 2 == 1) {
throw new IllegalArgumentException(
"Invalid hexadecimal String supplied.");
}
byte[] bytes = new byte[hexString.length() / 2];
for (int i = 0; i < hexString.length(); i = 2) {
bytes[i / 2] = hexToByte(hexString.substring(i, i 2));
}
return bytes;
}打印16进制；
代码语言：javascript复制public static void printHexString(String hint, byte[] b) {
Log.i(TAG, hint);
if (b == null){
return;
}
for (int i = 0; i < b.length; i ) {
String hex = Integer.toHexString(b[i] & 0xFF);
if (hex.length() == 1) {
hex = '0' hex;
}
Log.i(TAG, hex.toUpperCase() " ");
}
System.out.println("");
}java中的byte不是无符号整数，那么如何将byte变量判断0xff.
代码语言：javascript复制byte value = 0xff;
int header = (int)(value & 0xff);
if (header != 0xFF){
return data;
}转义处理：
代码语言：javascript复制static int escapte_fun(byte []out_data, byte[] sb, int sb_len){
int indx = 0;
int pos_sb = 0;
out_data[indx ] = (byte)sb[pos_sb ]; //head
int tmp_dlen =sb_len - 1;
/*消息转义，从包类型到消息体内容*/
for (int i=1; i<tmp_dlen; i )
{
int value = (byte)sb[i] & 0xff;
if (0xFF == value)
{
out_data[indx ] = (byte)0xFD;
out_data[indx ] = (byte)0x02;
}
else if (0xFE == value)
{
out_data[indx ] = (byte)0xFD;
out_data[indx ] = (byte)0x01;
}
else if (0xFD == value)
{
out_data[indx ] = (byte)0xFD;
out_data[indx ] = (byte)0x00;
}
else
{
out_data[indx ] = (byte)sb[i];
}
}
out_data[indx ] = (byte)0xFE;
return indx;
}
static void de_escabe_data(byte[] input, byte[] output){
int j= 0;
int i=0;
for (; i<input.length-2; i ){
int value = (byte)input[i] & 0xff;
int value_2 = (byte)input[i 1] & 0xff;
if (0xFD == value && value_2 == 0x02 )
{
output[j ] = (byte)0xFF;
i ;
}
else if (0xFD == value && value_2 == 0x01 )
{
output[j ] = (byte)0xFE;
i ;
}
else if (0xFD == value && value_2 == 0x00 )
{
output[j ] = (byte)0xFD;
i ;
}
else
{
output[j ] = (byte)input[i];
}
}
output[j ] = (byte)input[i ];
output[j ] = (byte)input[i];
}现在包括文言一心的AI，做这些简单的API实现，还是很方便的，分享出来，AI就能更聪明了。
最近还做了一个UTF8转GB2312的实现，代码最后还是文言一心生成的有效果。
首先是UTF8->Unicode， 然后Unicode转GB2312。
代码语言：javascript复制//获取utf8转unicode的字节个数
int GetUtf8ByteNumForWord(uint8_t firstCh)
{
uint8_t temp = 0x80;
int num = 0;
while (temp & firstCh)
{
num ;
temp = (temp >> 1);
}
printf("rnthe num is: %d", num);
return num;
}
这里strUnicode2GB就是根据查表法找到gb2312的字符。
switch (GetUtf8ByteNumForWord((uint8_t)temp_mesg[i]))
{
case 3:
//这里就开始进行UTF8->Unicode
recv_message[j] = ((temp_mesg[i] & 0x0F) << 4) | ((temp_mesg[i 1] >> 2) & 0x0F);
recv_message[j 1] = ((temp_mesg[i 1] & 0x03) << 6) (temp_mesg[i 2] & 0x3F);
printf("rbefore changing, recv_message: 0x%0X%0Xn", recv_message[j], recv_message[j 1]);
//取得Unicode的值
memset(temp_mesg_gb28181, 0x00, sizeof(temp_mesg_gb28181));
//根据这个值查表取得对应的GB2312的值
gbKey = strUnicode2GB((const unsigned char *)&recv_message[j], temp_mesg_gb28181, 2);
if (gbKey != 0)
{
//here change the byte
//不为0表示搜索到，将高低两个字节调换调成我要的形式
printf("rnafter changing, gb2312 key is: 0x%0X%0Xn", temp_mesg_gb28181[0], temp_mesg_gb28181[1]);
memcpy((recv_message j), &temp_mesg_gb28181[0], 2);
}
byteCount = 3;
break;
}
i = byteCount;
if (byteCount == 1)
{
j ;
}
else
{
j = 2;
}以后失业怕只是时间问题，毕竟这些码农的基础活，AI都能做了，最多也只能干个砖瓦匠糊墙的活了。
呱牛笔记
