Clean Code

length() == 0
)
marshalers.put(elementId, new BooleanArgumentMarshaler());
else if (elementTail.
equals("*")
)
marshalers.put(elementId, new StringArgumentMarshaler());
else if (elementTail.
equals("#")
)
marshalers.put(elementId, new IntegerArgumentMarshaler());

---

238
Chapter 14: Successive Refinement
else if (elementTail.equals("##"))
marshalers.put(elementId, new DoubleArgumentMarshaler());
else
throw new ParseException(String.format(
"Argument: %c has invalid format: %s.", elementId, elementTail), 0);
}
Next, we write the 
DoubleArgumentMarshaler
class.
private class DoubleArgumentMarshaler implements ArgumentMarshaler {
private double doubleValue = 0;
public void set(Iterator currentArgument) throws ArgsException {
String parameter = null;
try {
parameter = currentArgument.next();
doubleValue = Double.parseDouble(parameter);
} catch (NoSuchElementException e) {
errorCode = ErrorCode.MISSING_DOUBLE;
throw new ArgsException();
} catch (NumberFormatException e) {
errorParameter = parameter;
errorCode = ErrorCode.INVALID_DOUBLE;
throw new ArgsException();
}
}
public Object get() {
return doubleValue;
}
}
This forces us to add a new 
ErrorCode
.
private enum ErrorCode {
OK, MISSING_STRING, MISSING_INTEGER, INVALID_INTEGER, UNEXPECTED_ARGUMENT, 
MISSING_DOUBLE, INVALID_DOUBLE
}
And we need a 
getDouble
function.
public double getDouble(char arg) {
Args.ArgumentMarshaler am = marshalers.get(arg);