Clean Code

public void testMissingDouble() throws Exception {
Args args = new Args("x##", new String[]{"-x"});
assertFalse(args.isValid());
assertEquals(0, args.cardinality());
assertFalse(args.has('x'));
assertEquals(0.0, args.getDouble('x'), 0.01);
assertEquals("Could not find double parameter for -x.", 
args.errorMessage());
}
This passes as expected. We wrote it simply for completeness. 
The exception code is pretty ugly and doesn’t really belong in the 
Args
class. We are
also throwing out 
ParseException
, which doesn’t really belong to us. So let’s merge all the
exceptions into a single 
ArgsException
class and move it into its own module.
public class ArgsException extends Exception {
private char errorArgumentId = '\0';
private String errorParameter = "TILT";
private ErrorCode errorCode = ErrorCode.OK;
public ArgsException() {}
public ArgsException(String message) {super(message);}
public enum ErrorCode {
OK, MISSING_STRING, MISSING_INTEGER, INVALID_INTEGER, UNEXPECTED_ARGUMENT, 
MISSING_DOUBLE, INVALID_DOUBLE}
}
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240
Chapter 14: Successive Refinement
public class Args {
...
private char errorArgumentId = '\0';
private String errorParameter = "TILT";
private 
ArgsException
.ErrorCode errorCode = 
ArgsException
.ErrorCode.OK;
private List argsList;
public Args(String schema, String[] args) throws 
ArgsException
{
this.schema = schema;
argsList = Arrays.asList(args);
valid = parse();
}
private boolean parse() throws ArgsException {
if (schema.length() == 0 && argsList.size() == 0)
return true;
parseSchema();
try {
parseArguments();
} catch (