Client and backend. This class is shared: the same code is compiled into your app and into your server, so everything on this page works in both.

public final class Objects

Object
Objects

This is a compatibility class which supports the java.util.Objects API. On platforms that don’t support this class (e.g. Android) the build server will automatically remap all uses of java.util.Objects to use this implementation instead.

This class consists of static utility methods for operating on objects. These utilities include null-safe or null-tolerant methods for computing the hash code of an object, returning a string for an object, and comparing two objects.

Methods

`public static boolean equals(Object a, Object b)`	Returns true if the arguments are equal to each other and false otherwise.
`public static int hashCode(Object o)`	Returns the hash code of a non-null argument and 0 for a null argument.
`public static` `String toString(Object o)`
`public static` `String toString(Object o, String nullDefault)`
`public static <T> int compare(T a, T b,` `Comparator<? super T> c)`
`public static <T> T requireNonNull(T obj)`
`public static <T> T requireNonNull(T obj,` `String message)`
`public static boolean nonNull(Object obj)`
`public static boolean deepEquals(Object a, Object b)`
`public static int hash(Object... values)`
`public static boolean isNull(Object obj)`	Whether `obj` is null.
`public static <T> T requireNonNull(T obj,` `Supplier<String> messageSupplier)`	`obj`, or a NullPointerException whose message `messageSupplier` makes, only when it is needed.
`public static <T> T requireNonNullElse(T obj, T defaultObj)`	`obj`, or `defaultObj` when `obj` is null.
`public static <T> T requireNonNullElseGet(T obj,` `Supplier<? extends T> supplier)`	`obj`, or what `supplier` gives when `obj` is null.
`public static int checkIndex(int index, int length)`	`index`, if it lies in `[0, length)`.
`public static long checkIndex(long index, long length)`	`index`, if it lies in `[0, length)`.
`public static int checkFromToIndex(int fromIndex, int toIndex, int length)`	`fromIndex`, if `[fromIndex, toIndex)` lies in `[0, length)`.
`public static long checkFromToIndex(long fromIndex, long toIndex, long length)`	`fromIndex`, if `[fromIndex, toIndex)` lies in `[0, length)`.
`public static int checkFromIndexSize(int fromIndex, int size, int length)`	`fromIndex`, if `[fromIndex, fromIndex + size)` lies in `[0, length)`.
`public static long checkFromIndexSize(long fromIndex, long size, long length)`	`fromIndex`, if `[fromIndex, fromIndex + size)` lies in `[0, length)`.
`public static` `String toIdentityString(Object o)`	What `Object.toString` would answer for `o`, even when its class overrides it.

Inherited methods

From Object

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

Method details

equals

public static boolean equals(Object a, Object b)

Returns true if the arguments are equal to each other and false otherwise. Consequently, if both arguments are null, true is returned and if exactly one argument is null, false is returned. Otherwise, equality is determined by using the equals method of the first argument.

hashCode

public static int hashCode(Object o)

Returns the hash code of a non-null argument and 0 for a null argument.

toString

public static String toString(Object o)

toString

public static String toString(Object o, String nullDefault)

compare

public static <T> int compare(T a, T b, Comparator<? super T> c)

requireNonNull

public static <T> T requireNonNull(T obj)

requireNonNull

public static <T> T requireNonNull(T obj, String message)

nonNull

public static boolean nonNull(Object obj)

deepEquals

public static boolean deepEquals(Object a, Object b)

hash

public static int hash(Object... values)

isNull

public static boolean isNull(Object obj)

Whether obj is null.

requireNonNull

public static <T> T requireNonNull(T obj, Supplier<String> messageSupplier)

obj, or a NullPointerException whose message messageSupplier makes, only when it is needed.

requireNonNullElse

public static <T> T requireNonNullElse(T obj, T defaultObj)

obj, or defaultObj when obj is null.

Throws

NullPointerException: if both are null

requireNonNullElseGet

public static <T> T requireNonNullElseGet(T obj, Supplier<? extends T> supplier)

obj, or what supplier gives when obj is null.

Throws

NullPointerException: if obj is null and the supplier is null or gives null

checkIndex

public static int checkIndex(int index, int length)

index, if it lies in [0, length).

Throws

IndexOutOfBoundsException: otherwise

checkIndex

public static long checkIndex(long index, long length)

index, if it lies in [0, length).

checkFromToIndex

public static int checkFromToIndex(int fromIndex, int toIndex, int length)

fromIndex, if [fromIndex, toIndex) lies in [0, length).

checkFromToIndex

public static long checkFromToIndex(long fromIndex, long toIndex, long length)

fromIndex, if [fromIndex, toIndex) lies in [0, length).

checkFromIndexSize

public static int checkFromIndexSize(int fromIndex, int size, int length)

fromIndex, if [fromIndex, fromIndex + size) lies in [0, length).

checkFromIndexSize

public static long checkFromIndexSize(long fromIndex, long size, long length)

fromIndex, if [fromIndex, fromIndex + size) lies in [0, length).

toIdentityString

public static String toIdentityString(Object o)

What Object.toString would answer for o, even when its class overrides it.