org.yarnandtail.andhow.valuetype

Class FlagType

java.lang.Object

org.yarnandtail.andhow.valuetype.BaseValueType<Boolean>

org.yarnandtail.andhow.valuetype.FlagType

All Implemented Interfaces:

ValueType<Boolean>

public class FlagType
extends BaseValueType<Boolean>

Metadata and parsing for a Boolean type which is never null, similar to a 'nix flag behavior.

This would be used to parse a command line argument that is true by its presence, e.g.:
java MyClass launch
If launch is an AndHow property using the FlagType (i.e. FlagProp), launch will be considered true just by its presence.

This class is threadsafe and uses a singleton pattern to prevent multiple instances since all users can safely use the same instance.

Field Summary

Fields inherited from class org.yarnandtail.andhow.valuetype.BaseValueType

clazzType

Method Summary

Modifier and Type	Method and Description
Boolean	cast(Object o) Attempt to cast the passed object to the generic type T.
static FlagType	get() Deprecated. since 0.4.1. Use instance() instead
static FlagType	instance()
Boolean	parse(String sourceValue) Attempts to parse the passed String into the destinationType.

Methods inherited from class org.yarnandtail.andhow.valuetype.BaseValueType

getDestinationType, isParsable, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

get

@Deprecated
public static FlagType get()

Deprecated. since 0.4.1. Use instance() instead

Returns:

An instance of the FlagType()

instance

public static FlagType instance()

Returns:

An instance of the FlagType()

parse

public Boolean parse(String sourceValue)
              throws IllegalArgumentException

Description copied from interface: ValueType

Attempts to parse the passed String into the destinationType. All trimming (removing whitespace from around a value) should be assumed to already have happened for the incoming sourceValue by a Trimmer. Implementations should be careful to ONLY throw a ParsingException - Integers and other types may throw other unchecked exceptions when trying to convert values, which should be handled in this method and rethrown as a ParsingException. This method and toString(T) should be reversible: The object generated here should be toString-able to a String equal to the one passed this method.

Returns:

null if null, or a value of type T

Throws:

IllegalArgumentException

cast

public Boolean cast(Object o)
             throws RuntimeException

Description copied from interface: ValueType

Attempt to cast the passed object to the generic type T. AndHow uses this internally to cast values known to already be of type T, but were stored in a generic way. If used for unknown types that are not castable to T, it will throw a RuntimeException, though this should never happen unless used by application code.

Returns:

Throws:

RuntimeException