Package org.aksw.commons.util.obj

Class ObjectUtils

java.lang.Object

org.aksw.commons.util.obj.ObjectUtils

public class ObjectUtils
extends Object

Constructor Summary

Constructors

Constructor	Description
ObjectUtils()

Method Summary

Modifier and Type	Method	Description
static boolean	canCastAs(Class<?> clazz, Object o)	Check if the given object can be assigned to given class.
static <T> T	castAs(Class<T> clazz, Object o)
static <T> T	castAsOrNull(Class<T> clazz, Object o)
static <T> T	coalesce(Supplier<T>... ts)	Supplier-based coalesce function as described in https://benjiweber.co.uk/blog/2013/12/08/null-coalescing-in-java-8/ Example usage: coalesce(obj::getName, obj::getId, () -> obj.hasFoo() ? obj.foo().toString() : "bar")
static Class<?>	getClass(Object object)	Return an object's class - returns null for a null argument
static <T> T	mergeNonNull(T a, T b, BinaryOperator<T> merger)	If both arguments are non-null then invoke the merger with them and return its result.
static <T> T	mergeNonNull(T a, T b, BinaryOperator<T> combiner, Supplier<T> nullCase)	Similar to mergeNonNull(Object, Object, BinaryOperator) but with an additional supplier if both arguments are null.
static <T> T	requireNullOrEqual(T a, T b)	A consistency check utility.
static String	toStringWithIdentityHashCode(Object obj)	For a given object derive a string of the form className@identityHashCode
static String	toStringWithIdentityHashCode(Object obj, String nullDefault)	For a given object derive a string of the form className@identityHashCode
static <T> Optional<T>	tryCastAs(Class<T> clazz, Object o)

Methods inherited from class java.lang.Object

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

Constructor Details

ObjectUtils

public ObjectUtils()

Method Details

getClass

public static Class<?> getClass(Object object)

Return an object's class - returns null for a null argument

toStringWithIdentityHashCode

public static String toStringWithIdentityHashCode(Object obj)

For a given object derive a string of the form className@identityHashCode

toStringWithIdentityHashCode

public static String toStringWithIdentityHashCode(Object obj,
 String nullDefault)

For a given object derive a string of the form className@identityHashCode

canCastAs

public static boolean canCastAs(Class<?> clazz,
 Object o)

Check if the given object can be assigned to given class. Also works for primitive types, e.g. int can be assigned to Long.

tryCastAs

public static <T> Optional<T> tryCastAs(Class<T> clazz,
 Object o)

castAs

public static <T> T castAs(Class<T> clazz,
 Object o)

castAsOrNull

public static <T> T castAsOrNull(Class<T> clazz,
 Object o)

mergeNonNull

public static <T> T mergeNonNull(T a,
 T b,
 BinaryOperator<T> merger)

If both arguments are non-null then invoke the merger with them and return its result. If both arguments are null return null; Otherwise return the non-null argument.

mergeNonNull

public static <T> T mergeNonNull(T a,
 T b,
 BinaryOperator<T> combiner,
 Supplier<T> nullCase)

Similar to mergeNonNull(Object, Object, BinaryOperator) but with an additional supplier if both arguments are null.

coalesce

@SafeVarargs
public static <T> T coalesce(Supplier<T>... ts)

Supplier-based coalesce function as described in https://benjiweber.co.uk/blog/2013/12/08/null-coalescing-in-java-8/
Example usage: coalesce(obj::getName, obj::getId, () -> obj.hasFoo() ? obj.foo().toString() : "bar")

Type Parameters:

T -

Parameters:

ts -

Returns:

requireNullOrEqual

public static <T> T requireNullOrEqual(T a,
 T b)

A consistency check utility. If both given values are non-null then they must be equal otherwise an exception is raised. Returns the first non-null value (if present) otherwise null.