Question

java中如何实现BCD码字符串与16进制字符串的互转

如何实现16进制字符串转化成BCD码字符串？BCD码字符串转化成16进制的字符串？

Answer 1

nt main(void)
4{
5 unsigned char array[4] = {"0x0","0x0","0x02","0xe7"};
6 unsigned long num;
7 num = 0;
8 for(int i=0; i<sizeof(array); i++)
9 {
10 num<<=8;
11 num |= array[i];
12 }
13 printf("num = %d",num);
14 return 0;
15
16}

二进制,字节数组,字符,十六进制,BCD编码转换
* 把16进制字符串转换成字节数组
* @param hex
* @return
*/
public static byte[] hexStringToByte(String hex) {
int len = (hex.length() / 2);
byte[] result = new byte[len];
char[] achar = hex.toCharArray();
for (int i = 0; i < len; i++) {
int pos = i * 2;
result[i] = (byte) (toByte(achar[pos]) << 4 | toByte(achar[pos + 1]));
}
return result;
}

private static byte toByte(char c) {
byte b = (byte) "0123456789ABCDEF".indexOf(c);
return b;
}

public static final String bytesToHexString(byte[] bArray) {
StringBuffer sb = new StringBuffer(bArray.length);
String sTemp;
for (int i = 0; i < bArray.length; i++) {
sTemp = Integer.toHexString(0xFF & bArray[i]);
if (sTemp.length() < 2)
sb.append(0);
sb.append(sTemp.toUpperCase());
}
return sb.toString();
}

public static final Object bytesToObject(byte[] bytes) throws IOException, ClassNotFoundException {
ByteArrayInputStream in = new ByteArrayInputStream(bytes);
ObjectInputStream oi = new ObjectInputStream(in);
Object o = oi.readObject();
oi.close();
return o;
}

public static final byte[] objectToBytes(Serializable s) throws IOException {
ByteArrayOutputStream out = new ByteArrayOutputStream();
ObjectOutputStream ot = new ObjectOutputStream(out);
ot.writeObject(s);
ot.flush();
ot.close();
return out.toByteArray();
}

public static final String objectToHexString(Serializable s) throws IOException{
return bytesToHexString(objectToBytes(s));
}

public static final Object hexStringToObject(String hex) throws IOException, ClassNotFoundException{
return bytesToObject(hexStringToByte(hex));
}

public static String bcd2Str(byte[] bytes){
StringBuffer temp=new StringBuffer(bytes.length*2);

for(int i=0;i<bytes.length;i++){
temp.append((byte)((bytes[i]& 0xf0)>>>4));
temp.append((byte)(bytes[i]& 0x0f));
}
return temp.toString().substring(0,1).equalsIgnoreCase("0")?temp.toString().substring(1):temp.toString();
}

public static byte[] str2Bcd(String asc) {
int len = asc.length();
int mod = len % 2;

if (mod != 0) {
asc = "0" + asc;
len = asc.length();
}

byte abt[] = new byte[len];
if (len >= 2) {
len = len / 2;
}

byte bbt[] = new byte[len];
abt = asc.getBytes();
int j, k;

for (int p = 0; p < asc.length()/2; p++) {
if ( (abt[2 * p] >= '0') && (abt[2 * p] <= '9')) {
j = abt[2 * p] - '0';
} else if ( (abt[2 * p] >= 'a') && (abt[2 * p] <= 'z')) {
j = abt[2 * p] - 'a' + 0x0a;
} else {
j = abt[2 * p] - 'A' + 0x0a;
}

if ( (abt[2 * p + 1] >= '0') && (abt[2 * p + 1] <= '9')) {
k = abt[2 * p + 1] - '0';
} else if ( (abt[2 * p + 1] >= 'a') && (abt[2 * p + 1] <= 'z')) {
k = abt[2 * p + 1] - 'a' + 0x0a;
}else {
k = abt[2 * p + 1] - 'A' + 0x0a;
}

int a = (j << 4) + k;
byte b = (byte) a;
bbt[p] = b;
}
return bbt;
}

public static String BCD2ASC(byte[] bytes) {
StringBuffer temp = new StringBuffer(bytes.length * 2);

for (int i = 0; i < bytes.length; i++) {
int h = ((bytes[i] & 0xf0) >>> 4);
int l = (bytes[i] & 0x0f);
temp.append(BToA[h]).append( BToA[l]);
}
return temp.toString() ;
}

public static String MD5EncodeToHex(String origin) {
return bytesToHexString(MD5Encode(origin));
}

public static byte[] MD5Encode(String origin){
return MD5Encode(origin.getBytes());
}

public static byte[] MD5Encode(byte[] bytes){
MessageDigest md=null;
try {
md = MessageDigest.getInstance("MD5");
return md.digest(bytes);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
return new byte[0];
}

}
//关于byte: signed byte 把 0x00 ~ 0xff 映射成范围 0~127和 -128~-1 两段,比较简单的办法用 (b+256)%256的办法令其值回到0~255，或者用&0xff并赋给一个int