TBCD编码&解码

TBCD编码最直观的人看解析的方法：把单字节的低四位和高四位互换，字节之间顺序别变。直接就好了，F就是空，什么都没有。 比如：

TBCD编码：0x31 0x55 0x40 0x20 0x79 0xF9 解码后原始：13 5504 02 97 9

以下是编码、解码代码 // package tbcd; /**

* This sample code demonstrates how a character string can be convered to * a TBCD (Telephony Binary Coded Decimal) string and vice versa. */

public class TBCDUtil {

private static String cTBCDSymbolString = \

private static char[] cTBCDSymbols = cTBCDSymbolString.toCharArray();

public static void main(String[] args) {

if (args.length == 0) return;

byte[] tbcd = parseTBCD(args[0]);

System.out.println(\System.out.println(\ }

/* * This method converts a TBCD string to a character string. */

public static java.lang.StringtoTBCD (byte[] tbcd) {

int size = (tbcd == null ? 0 : tbcd.length);

StringBuffer buffer = new StringBuffer(2*size); for (inti=0; i

int n2 = (octet >> 4) & 0xF; int n1 = octet & 0xF;

if (n1 == 15) {

throw new NumberFormatException(\ }

buffer.append(cTBCDSymbols[n1]); if (n2 == 15) { if (i != size-1)

throw new NumberFormatException(\ } else

buffer.append(cTBCDSymbols[n2]); }

returnbuffer.toString(); }

/* * This method converts a character string to a TBCD string. */ public static byte[] parseTBCD (java.lang.Stringtbcd) { int length = (tbcd == null ? 0:tbcd.length()); int size = (length + 1)/2;

byte[] buffer = new byte[size];

for (inti=0, i1=0, i2=1; i

char c = tbcd.charAt(i1);

int n2 = getTBCDNibble(c, i1); int octet = 0; int n1 = 15; if (i2 < length) {

c = tbcd.charAt(i2);

n1 = getTBCDNibble(c, i2); }

octet = (n1 << 4) + n2;

buffer[i] = (byte)(octet & 0xFF); }

return buffer; }

private static intgetTBCDNibble(char c, int i1) {

int n = Character.digit(c, 10);

if (n < 0 || n > 9) {

switch (c) { case '*':

n = 10; break; case '#':

n = 11; break; case 'a':

n = 12; break; case 'b':

n = 13; break; case 'c':

n = 14; break; default:

throw new NumberFormatException(\ + \ } } return n; }

/* Hex chars */

private static final byte[] HEX_CHAR = new byte[]

{ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' }; /*

* Helper function that dumps an array of bytes in the hexadecimal format. */

public static final String dumpBytes( byte[] buffer ) {

if ( buffer == null ) { return \ }

StringBuffersb = new StringBuffer();

for ( inti = 0; i

sb.append( \( char ) ( HEX_CHAR[buffer[i] & 0x000F] ) ).append( \

}

returnsb.toString(); } }