Added new IsoTypes: BINARY, LLBIN and LLLBIN. Similar to ALPHA, LLVAR and LLLVAR but they handle binary values that get translated to byte arrays, directly if using binary coding, or hex-encoded if using ASCII.

git-svn-id: https://j8583.svn.sourceforge.net/svnroot/j8583/j8583@63 db60a039-f72e-0410-b1d2-baa000846441

src/main/java/com/solab/iso8583/util/HexCodec.java

@@ -0,0 +1,63 @@
+package com.solab.iso8583.util;
+
+/** Utility class to perform HEX encoding/decoding of values. */
+public class HexCodec {
+
+	static final char[] HEX = new char[]{ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
+
+	public static String hexEncode(byte[] buffer) {
+		if (buffer.length == 0) {
+			return "";
+		}
+		int holder = 0;
+		char[] chars = new char[buffer.length * 2];
+		for (int i = 0; i < buffer.length; i++) {
+			holder = (buffer[i] & 0xf0) >> 4;
+			chars[i * 2] = HEX[holder];
+			holder = buffer[i] & 0x0f;
+			chars[(i * 2) + 1] = HEX[holder];
+		}
+		return new String(chars);
+	}
+
+	public static byte[] hexDecode(String hex) {
+		//A null string returns an empty array
+		if (hex == null || hex.length() == 0) {
+			return new byte[0];
+		} else if (hex.length() < 3) {
+			return new byte[]{ (byte)(Integer.parseInt(hex, 16) & 0xff) };
+		}
+		//Adjust accordingly for odd-length strings
+		int count = hex.length();
+		int nibble = 0;
+		if (count % 2 != 0) {
+			count++;
+			nibble = 1;
+		}
+		byte[] buf = new byte[count / 2];
+		char c = 0;
+		int holder = 0;
+		int pos = 0;
+		for (int i = 0; i < buf.length; i++) {
+		    for (int z = 0; z < 2; z++) {
+		        c = hex.charAt(pos++);
+		        if (c >= 'A' && c <= 'F') {
+		            c -= 55;
+		        } else if (c >= '0' && c <= '9') {
+		            c -= 48;
+		        } else if (c >= 'a' && c <= 'f') {
+		            c -= 87;
+		        }
+		        if (nibble == 0) {
+		            holder = c << 4;
+		        } else {
+		            holder |= c;
+		            buf[i] = (byte)holder;
+		        }
+		        nibble = 1 - nibble;
+		    }
+		}
+		return buf;
+	}
+
+}