/**
* find a option by its type in a scheme. This involves iterating through the list of options. The
* main reason for doing it this way is to avoid being dependent on the order in which the options
* are coded in the xml, which is not explicitly constrained.
*/
private Option findOption(Level level, String optionKey) {
Option option = null;
for (Enumeration e = level.enumerateOption(); e.hasMoreElements(); ) {
Option opt = (Option) e.nextElement();
if (opt.getOptionKey().equals(optionKey)) {
option = opt;
break;
}
}
if (option == null)
throw new Error("Couldn't find option for " + optionKey + " in level " + level);
return option;
}
/** convert from a particular scheme / level */
private String convertLevel(
Scheme tdtscheme,
Level tdtlevel,
String input,
Map<String, String> inputParameters,
LevelTypeList outboundlevel) {
String outboundstring;
Map<String, String> extraparams =
// new NoisyMap
(new HashMap<String, String>(inputParameters));
// get the scheme's option key, which is the name of a
// parameter whose value is matched to the option key of the
// level.
String optionkey = tdtscheme.getOptionKey();
String optionValue = extraparams.get(optionkey);
// the name of a parameter which allows the appropriate option
// to be selected
// now consider the various options within the scheme and
// level for each option element inside the level, check
// whether the pattern attribute matches as a regular
// expression
String matchingOptionKey = null;
Option matchingOption = null;
Matcher prefixMatcher = null;
for (Enumeration e = tdtlevel.enumerateOption(); e.hasMoreElements(); ) {
Option opt = (Option) e.nextElement();
if (optionValue == null || optionValue.equals(opt.getOptionKey())) {
// possible match
Matcher matcher = Pattern.compile(opt.getPattern()).matcher(input);
if (matcher.matches()) {
if (prefixMatcher != null) throw new TDTException("Multiple patterns matched");
prefixMatcher = matcher;
matchingOptionKey = opt.getOptionKey();
matchingOption = opt;
}
}
}
if (prefixMatcher == null) throw new TDTException("No patterns matched");
optionValue = matchingOptionKey;
for (Enumeration e = matchingOption.enumerateField(); e.hasMoreElements(); ) {
Field field = (Field) e.nextElement();
int seq = field.getSeq();
String strfieldname = field.getName();
int fieldlength = field.getLength();
String strfieldvalue = prefixMatcher.group(seq);
// System.out.println(" processing field " + strfieldname + " = '" + strfieldvalue + "'");
if (field.getCompaction() == null) {
// if compaction is null, treat field as an integer
if (field.getCharacterSet() != null) { // if the character set is specified
Matcher charsetmatcher =
Pattern.compile("^" + field.getCharacterSet() + "$").matcher(strfieldvalue);
if (!charsetmatcher.matches()) {
throw new TDTException(
"field "
+ strfieldname
+ " ("
+ strfieldvalue
+ ") does not conform to the allowed character set ("
+ field.getCharacterSet()
+ ") ");
}
}
BigInteger bigvalue = null;
if (tdtlevel.getType() == LevelTypeList.BINARY) { // if the input was BINARY
bigvalue = new BigInteger(strfieldvalue, 2);
extraparams.put(strfieldname, bigvalue.toString());
} else {
if (field.getDecimalMinimum() != null || field.getDecimalMaximum() != null)
bigvalue = new BigInteger(strfieldvalue);
extraparams.put(strfieldname, strfieldvalue);
}
if (field.getDecimalMinimum() != null) { // if the decimal minimum is specified
BigInteger bigmin = new BigInteger(field.getDecimalMinimum());
if (bigvalue.compareTo(bigmin)
== -1) { // throw an exception if the field value is less than the decimal minimum
throw new TDTException(
"field "
+ strfieldname
+ " ("
+ bigvalue
+ ") is less than DecimalMinimum ("
+ field.getDecimalMinimum()
+ ") allowed");
}
}
if (field.getDecimalMaximum() != null) { // if the decimal maximum is specified
BigInteger bigmax = new BigInteger(field.getDecimalMaximum());
if (bigvalue.compareTo(bigmax)
== 1) { // throw an excpetion if the field value is greater than the decimal maximum
throw new TDTException(
"field "
+ strfieldname
+ " ("
+ bigvalue
+ ") is greater than DecimalMaximum ("
+ field.getDecimalMaximum()
+ ") allowed");
}
}
// after extracting the field, it may be necessary to pad it.
padField(extraparams, field);
} else {
// compaction is specified - interpret binary as a string value using a truncated byte per
// character
CompactionMethodList compaction = field.getCompaction();
PadDirectionList padDir = field.getPadDir();
String padchar = field.getPadChar();
String s;
if (compaction == CompactionMethodList.VALUE_5)
// "5-bit"
s = bin2uppercasefive(strfieldvalue);
else if (compaction == CompactionMethodList.VALUE_4)
// 6-bit
s = bin2alphanumsix(strfieldvalue);
else if (compaction == CompactionMethodList.VALUE_3)
// 7-bit
s = bin2asciiseven(strfieldvalue);
else if (compaction == CompactionMethodList.VALUE_2)
// 8-bit
s = bin2bytestring(strfieldvalue);
else throw new Error("unsupported compaction method " + compaction);
extraparams.put(strfieldname, stripPadChar(s, padDir, padchar));
}
} // for each field;
/**
* the EXTRACT rules are performed after parsing the input, in order to determine additional
* fields that are to be derived from the fields obtained by the pattern match process
*/
int seq = 0;
for (Enumeration e = tdtlevel.enumerateRule(); e.hasMoreElements(); ) {
Rule tdtrule = (Rule) e.nextElement();
if (tdtrule.getType() == ModeList.EXTRACT) {
assert seq < tdtrule.getSeq() : "Rule out of sequence order";
seq = tdtrule.getSeq();
processRules(extraparams, tdtrule);
}
}
/**
* Now we need to consider the corresponding output level and output option. The scheme must
* remain the same, as must the value of optionkey (to select the corresponding option element
* nested within the required outbound level)
*/
Level tdtoutlevel = findLevel(tdtscheme, outboundlevel);
Option tdtoutoption = findOption(tdtoutlevel, optionValue);
/**
* the FORMAT rules are performed before formatting the output, in order to determine additional
* fields that are required for preparation of the outbound format
*/
seq = 0;
for (Enumeration e = tdtoutlevel.enumerateRule(); e.hasMoreElements(); ) {
Rule tdtrule = (Rule) e.nextElement();
if (tdtrule.getType() == ModeList.FORMAT) {
assert seq < tdtrule.getSeq() : "Rule out of sequence order";
seq = tdtrule.getSeq();
processRules(extraparams, tdtrule);
}
}
/**
* Now we need to ensure that all fields required for the outbound grammar are suitably padded
* etc. processPadding takes care of firstly padding the non-binary fields if padChar and
* padDir, length are specified then (if necessary) converting to binary and padding the binary
* representation to the left with zeros if the bit string is has fewer bits than the bitLength
* attribute specifies. N.B. TDTv1.1 will be more specific about bit-level padding rather than
* assuming that it is always to the left with the zero bit.
*/
// System.out.println(" prior to processPadding, " + extraparams);
for (Enumeration e = tdtoutoption.enumerateField(); e.hasMoreElements(); ) {
Field field = (Field) e.nextElement();
// processPadding(extraparams, field, outboundlevel, tdtoutoption);
padField(extraparams, field);
if (outboundlevel == LevelTypeList.BINARY) binaryPadding(extraparams, field);
}
/**
* Construct the output from the specified grammar (in ABNF format) together with the field
* values stored in inputparams
*/
outboundstring = buildGrammar(tdtoutoption.getGrammar(), extraparams);
// System.out.println("final extraparams = " + extraparams);
// System.out.println("returned " + outboundstring);
return outboundstring;
}