org.apache.juneau.internal

Class ObjectUtils

java.lang.Object

org.apache.juneau.internal.ObjectUtils

public final class ObjectUtils
extends Object

Utility class for efficiently converting objects between types.

If the value isn't an instance of the specified type, then converts the value if possible.

The following conversions are valid:

Convert to type	Valid input value types	Notes
A class that is the normal type of a registered PojoSwap.	A value whose class matches the transformed type of that registered PojoSwap.
A class that is the transformed type of a registered PojoSwap.	A value whose class matches the normal type of that registered PojoSwap.
Number (e.g. Integer, Short, Float,...) Number.TYPE (e.g. Integer.TYPE, Short.TYPE, Float.TYPE,...)	Number, String, null	For primitive TYPES, null returns the JVM default value for that type.
Map (e.g. Map, HashMap, TreeMap, ObjectMap)	Map	If Map is not constructible, a ObjectMap is created.
Collection (e.g. List, LinkedList, HashSet, ObjectList)	Collection<Object> Object[]	If Collection is not constructible, a ObjectList is created.
X[] (array of any type X)	List<X>
X[][] (multi-dimensional arrays)	List<List<X>> List<X[]> List[]<X>
Enum	String
Bean	Map
String	Anything	Arrays are converted to JSON arrays
Anything with one of the following methods: public static T fromString(String) public static T valueOf(String) public T(String)	String

Constructor Summary

Constructors

Constructor and Description
ObjectUtils()

Method Summary

Modifier and Type	Method and Description
static boolean	equals(Object o1, Object o2) Returns true if the specified objects are equal.
static <T> T	firstNonNull(T[] t) Returns the first non-null value in the specified array
static boolean	isEmpty(Object o) Returns true if the specified object is empty.
static Boolean	toBoolean(Object o) Converts an object to a Boolean.
static Integer	toInteger(Object o) Converts an object to an Integer.
static <T> T	toMemberType(Object outer, Object value, Class<T> type) Converts the specified object to the specified type.
static Number	toNumber(Object o) Converts an object to a Number.
static <T> T	toType(Object value, Class<T> type) Converts the specified object to the specified type.
static <T> T	toType(Object value, Class<T> type, Type... args) Converts the specified object to the specified type.

Methods inherited from class java.lang.Object

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

Constructor Detail

ObjectUtils

public ObjectUtils()

Method Detail

toType

public static <T> T toType(Object value,
                           Class<T> type)

Converts the specified object to the specified type.

Type Parameters:

T - The class type to convert the value to.

Parameters:

value - The value to convert.

type - The class type to convert the value to.

Returns:

The converted value.

Throws:

InvalidDataConversionException - If the specified value cannot be converted to the specified type.

toType

public static <T> T toType(Object value,
                           Class<T> type,
                           Type... args)

Converts the specified object to the specified type.

Type Parameters:

T - The class type to convert the value to.

Parameters:

value - The value to convert.

type - The class type to convert the value to.

args - The type arguments.

Returns:

The converted value.

Throws:

InvalidDataConversionException - If the specified value cannot be converted to the specified type.

toMemberType

public static <T> T toMemberType(Object outer,
                                 Object value,
                                 Class<T> type)

Converts the specified object to the specified type.

Type Parameters:

T - The class type to convert the value to.

Parameters:

outer - If class is a member class, this is the instance of the containing class. Should be null if not a member class.

value - The value to convert.

type - The class type to convert the value to.

Returns:

The converted value.

Throws:

InvalidDataConversionException - If the specified value cannot be converted to the specified type.

equals

public static boolean equals(Object o1,
                             Object o2)

Returns true if the specified objects are equal.

Gracefully handles nulls.

Parameters:

o1 - Object #1

o2 - Object #2

Returns:

true if the objects are equal or both null.

isEmpty

public static boolean isEmpty(Object o)

Returns true if the specified object is empty.

Return true if the value is any of the following:

• null
• An empty Collection
• An empty Map
• An empty array
• An empty CharSequence
• An empty String when serialized to a string using Object.toString().

Parameters:

o - The object to test.

Returns:

true if the specified object is empty.

firstNonNull

public static <T> T firstNonNull(T[] t)

Returns the first non-null value in the specified array

Parameters:

t -

Returns:

The first non-null value, or null if the array is null or empty or contains only null values.

toBoolean

public static Boolean toBoolean(Object o)

Converts an object to a Boolean.

Parameters:

o - The object to convert.

Returns:

The converted object.

toInteger

public static Integer toInteger(Object o)

Converts an object to an Integer.

Parameters:

o - The object to convert.

Returns:

The converted object.

toNumber

public static Number toNumber(Object o)

Converts an object to a Number.

Parameters:

o - The object to convert.

Returns:

The converted object.