FieldParseInfo is now an abstract class, with a concrete subclass for each IsoType. This greatly improves the parsing speed.

git-svn-id: https://j8583.svn.sourceforge.net/svnroot/j8583/j8583@66 db60a039-f72e-0410-b1d2-baa000846441

src/main/java/com/solab/iso8583/parse/NumericParseInfo.java

@@ -0,0 +1,44 @@
+package com.solab.iso8583.parse;
+
+import java.math.BigInteger;
+import java.text.ParseException;
+
+import com.solab.iso8583.CustomField;
+import com.solab.iso8583.IsoType;
+import com.solab.iso8583.IsoValue;
+
+/** This class is used to parse NUMERIC fields.
+ * 
+ * @author Enrique Zamudio
+ */
+public class NumericParseInfo extends AlphaNumericFieldParseInfo {
+
+	public NumericParseInfo(int len) {
+		super(IsoType.NUMERIC, len);
+	}
+
+	public <T extends Object> IsoValue<?> parseBinary(byte[] buf, int pos, CustomField<T> custom) throws ParseException {
+		//A long covers up to 18 digits
+		if (length < 19) {
+			long l = 0;
+			long power = 1L;
+			for (int i = pos + (length / 2) + (length % 2) - 1; i >= pos; i--) {
+				l += (buf[i] & 0x0f) * power;
+				power *= 10L;
+				l += ((buf[i] & 0xf0) >> 4) * power;
+				power *= 10L;
+			}
+			return new IsoValue<Number>(IsoType.NUMERIC, l, length, null);
+		} else {
+			//Use a BigInteger
+			char[] digits = new char[length];
+			int start = 0;
+			for (int i = pos; i < pos + (length / 2) + (length % 2); i++) {
+				digits[start++] = (char)(((buf[i] & 0xf0) >> 4) + 48);
+				digits[start++] = (char)((buf[i] & 0x0f) + 48);
+			}
+			return new IsoValue<Number>(IsoType.NUMERIC, new BigInteger(new String(digits)), length, null);
+		}
+	}
+
+}