public String toUsageString() {
StringBuilder sb = new StringBuilder();
for (Argument a : parameters.values()) {
sb.append(a.toUsageString("\t"));
}
return sb.toString();
}
/*
verifies that each of our registered parameters has a value, either given or default
throws an exeption otherwise
*/
private void verify() throws Exception {
for (Argument parameter : parameters.values()) {
if (parameter.getValue() == null && parameter.getDefaultValue() == null) {
throw new Exception(
String.format("Argument '%s' is required. Please see usage.", parameter.name));
}
}
}
public Object getValue(String argumentName) {
Object value = null;
argumentName = argumentName.toLowerCase();
if (parameters.containsKey(argumentName)) {
Argument argument = parameters.get(argumentName);
value = argument.getValue();
if (value == null) {
String defaultValue = argument.getDefaultValue();
try {
value = argument.getHandler().tryArgument(defaultValue);
} catch (Exception e) {
}
}
}
return value;
}
/*
Tries each handler for the given parameter and returns a success boolean
*/
private boolean parseKV(String key, String value) throws Exception {
boolean success = false;
// must have a registered handler; see registerArgumentHandler()
if (!parameters.containsKey(key)) {
throw new Exception(key + " is not a valid argument");
}
Argument arg = parameters.get(key);
// don't allow dupes
if (arg.getValue() != null) {
throw new Exception("Duplicate arguments: " + key);
}
try {
// handler returns null if it can't handle the argument
// it can throw an exception if the argument is an unacceptable value
Object param = arg.getHandler().tryArgument(value);
if (param != null) {
arg.setValue(param);
success = true;
}
} catch (Exception e) {
throw new Exception("Bad argument value for '" + key + "': " + e.getMessage());
}
return success;
}
/*
Register a new Argument handler for a desired parameter
*/
public void registerArgument(Argument argument) {
parameters.put(argument.getName().toLowerCase(), argument);
}