/**
* Get the field type of a Field instance.
*
* @param field the field instance we want the type for.
* @return the type of the {@code field} in question.
*/
private static FieldType fieldTypeOf(Field field, Flag flag) {
if (field.getType().isAssignableFrom(Long.TYPE)
|| field.getType().isAssignableFrom(Long.class)) {
return FieldType.LONG;
}
if (field.getType().isAssignableFrom(Boolean.TYPE)
|| field.getType().isAssignableFrom(Boolean.class)) {
return FieldType.BOOLEAN;
}
if (field.getType().isAssignableFrom(String.class)) {
return FieldType.STRING;
}
if (field.getType().isAssignableFrom(Integer.TYPE)
|| field.getType().isAssignableFrom(Integer.class)) {
return FieldType.INTEGER;
}
if (flag.options() != NoOption.class && field.getType().isAssignableFrom(flag.options())) {
return FieldType.ENUM;
}
return FieldType.UNKNOWN;
}
private Flags loadOpts(Object o, boolean instanced) {
final Field[] declaredFields;
Class<?> c = null;
if (instanced) {
declaredFields = o.getClass().getDeclaredFields();
} else {
c = ((Class<?>) o);
declaredFields = c.getDeclaredFields();
}
for (Field field : declaredFields) {
Flag flag = field.getAnnotation(Flag.class);
// Check if we found a flag annotation for this field.
if (null == flag) {
continue;
}
// Flag fields must be static if you are initializing the flags through a Class instance.
if (!instanced && !Modifier.isStatic(field.getModifiers())) {
throw new IllegalArgumentException(
"Field "
+ field.toGenericString()
+ " is not static. Flag fields "
+ "must be static when initializing through a Class instance.");
}
String name = flag.name();
String description = flag.description();
// Determine the type of field
FieldType type = fieldTypeOf(field, flag);
switch (type) {
case INTEGER:
OptionSpec<Integer> intOption;
if (flag.required()) {
intOption =
optionParser.accepts(name, description).withRequiredArg().ofType(Integer.class);
} else {
intOption =
optionParser.accepts(name, description).withOptionalArg().ofType(Integer.class);
}
if (instanced) {
addInstancedOption(type, flag, field, intOption, o);
} else {
addOption(type, flag, field, intOption, c);
}
break;
case STRING:
OptionSpec<String> stringOption;
if (flag.required()) {
stringOption =
optionParser.accepts(name, description).withRequiredArg().ofType(String.class);
} else {
stringOption =
optionParser.accepts(name, description).withOptionalArg().ofType(String.class);
}
if (instanced) {
addInstancedOption(type, flag, field, stringOption, o);
} else {
addOption(type, flag, field, stringOption, c);
}
break;
case BOOLEAN:
OptionSpec<Boolean> booleanOption;
if (flag.required()) {
booleanOption =
optionParser.accepts(name, description).withOptionalArg().ofType(Boolean.class);
} else {
booleanOption =
optionParser.accepts(name, description).withOptionalArg().ofType(Boolean.class);
}
if (instanced) {
addInstancedOption(type, flag, field, booleanOption, o);
} else {
addOption(type, flag, field, booleanOption, c);
}
break;
case LONG:
OptionSpec<Long> longOption;
if (flag.required()) {
longOption =
optionParser.accepts(name, description).withRequiredArg().ofType(Long.class);
} else {
longOption =
optionParser.accepts(name, description).withOptionalArg().ofType(Long.class);
}
if (instanced) {
addInstancedOption(type, flag, field, longOption, o);
} else {
addOption(type, flag, field, longOption, c);
}
break;
case ENUM:
Class<? extends Enum<?>> enumClass = flag.options();
Object[] enumConstants = enumClass.getEnumConstants();
if (enumConstants == null) {
throw new IllegalArgumentException(
"Field " + field.toGenericString() + " is not an enum type.");
}
for (Object object : enumConstants) {
addEnumOption(enumClass, object.toString());
}
OptionSpec<?> enumOption;
if (flag.required()) {
enumOption =
optionParser.accepts(name, description).withRequiredArg().ofType(enumClass);
} else {
enumOption =
optionParser.accepts(name, description).withOptionalArg().ofType(enumClass);
}
if (instanced) {
addInstancedOption(type, flag, field, enumOption, o);
} else {
addOption(type, flag, field, enumOption, c);
}
break;
case UNKNOWN:
default:
throw new IllegalArgumentException(
"Field " + field.toGenericString() + " is not of a supported type.");
}
}
return this;
}