com.annimon.stream

Class Objects

java.lang.Object

com.annimon.stream.Objects

public final class Objects
extends java.lang.Object

Common operations with Object.

Method Summary

Modifier and Type	Method and Description
static <T> int	compare(T a, T b, java.util.Comparator<? super T> c) Compares two objects with provided comparator.
static int	compareInt(int x, int y) Compares two int values.
static int	compareLong(long x, long y) Compares two long values.
static boolean	deepEquals(java.lang.Object a, java.lang.Object b) Checks deep equality of two objects.
static boolean	equals(java.lang.Object a, java.lang.Object b) Checks equality of two objects.
static int	hash(java.lang.Object... values) Returns the hash code for objects.
static int	hashCode(java.lang.Object o) Returns the hash code of object.
static boolean	isNull(java.lang.Object obj) Checks that object reference is null.
static boolean	nonNull(java.lang.Object obj) Checks that object reference is not null.
static <T> T	requireNonNull(T obj) Checks that object reference is not null.
static <T> T	requireNonNull(T obj, java.lang.String message) Checks that object reference is not null.
static <T> T	requireNonNull(T obj, Supplier<java.lang.String> messageSupplier) Checks that object reference is not null.
static <T> java.util.Collection<T>	requireNonNullElements(java.util.Collection<T> collection) Checks that collection and its elements are non-null.
static <T> T	requireNonNullElse(T obj, T defaultObj) Returns the first object if it is non-null, returns the non-null second object otherwise.
static <T> T	requireNonNullElseGet(T obj, Supplier<? extends T> supplier) Returns the first object if it is non-null, returns the non-null supplier's result otherwise.
static java.lang.String	toString(java.lang.Object o, java.lang.String nullDefault) Returns result of calling toString on object or nullDefault if object is null.

Methods inherited from class java.lang.Object

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

Method Detail

equals

@Contract(pure=true)
public static boolean equals(@Nullable
                                                  java.lang.Object a,
                                                  @Nullable
                                                  java.lang.Object b)

Checks equality of two objects.

Parameters:

a - an object

b - an object

Returns:

true if objects are equals, false otherwise

deepEquals

@Contract(pure=true)
public static boolean deepEquals(@Nullable
                                                      java.lang.Object a,
                                                      @Nullable
                                                      java.lang.Object b)

Checks deep equality of two objects.

Parameters:

a - an object

b - an object

Returns:

true if objects are deeply equals, false otherwise

Since:

1.2.0

See Also:

Arrays.deepEquals(Object[], Object[]), equals(Object, Object)

hashCode

@Contract(pure=true)
public static int hashCode(@Nullable
                                                java.lang.Object o)

Returns the hash code of object.

Parameters:

o - an object

Returns:

the hash code

hash

@Contract(pure=true)
public static int hash(@Nullable
                                            java.lang.Object... values)

Returns the hash code for objects.

Parameters:

values - the values

Returns:

the hash code

toString

@NotNull
 @Contract(value="null, _ -> param2")
public static java.lang.String toString(@Nullable
                                                                                       java.lang.Object o,
                                                                                       @NotNull
                                                                                       java.lang.String nullDefault)

Returns result of calling toString on object or nullDefault if object is null.

Parameters:

o - an object

nullDefault - a string to return if object is null

Returns:

a result of calling toString on object or nullDefault if object is null.

compare

@Contract(pure=true)
public static <T> int compare(@Nullable
                                                   T a,
                                                   @Nullable
                                                   T b,
                                                   @NotNull
                                                   java.util.Comparator<? super T> c)

Compares two objects with provided comparator.

Type Parameters:

T - the type of the arguments

Parameters:

a - an object

b - an object

c - the comparator

Returns:

comparing result

compareInt

@Contract(pure=true)
public static int compareInt(int x,
                                                  int y)

Compares two int values.

Parameters:

x - the first int value

y - the second int value

Returns:

comparing result

Since:

1.1.6

compareLong

@Contract(pure=true)
public static int compareLong(long x,
                                                   long y)

Compares two long values.

Parameters:

x - the first long value

y - the second long value

Returns:

comparing result

Since:

1.1.6

requireNonNull

@NotNull
 @Contract(value="null -> fail; !null -> param1",
          pure=true)
public static <T> T requireNonNull(@Nullable
                                                                                                                   T obj)

Checks that object reference is not null.

Type Parameters:

T - the type of the object

Parameters:

obj - an object

Returns:

a source object if it is not null

Throws:

java.lang.NullPointerException - if object is null

See Also:

requireNonNull(java.lang.Object, java.lang.String)

requireNonNull

@NotNull
 @Contract(value="null, _ -> fail; !null, _ -> param1",
          pure=true)
public static <T> T requireNonNull(@Nullable
                                                                                                                         T obj,
                                                                                                                         @NotNull
                                                                                                                         java.lang.String message)

Checks that object reference is not null.

Type Parameters:

T - the type of the object

Parameters:

obj - an object

message - a message to be used as exception details

Returns:

a source object if it is not null

Throws:

java.lang.NullPointerException - if object is null

See Also:

requireNonNull(java.lang.Object)

requireNonNull

@NotNull
 @Contract(value="null, _ -> fail; !null, _ -> param1")
public static <T> T requireNonNull(@Nullable
                                                                                                    T obj,
                                                                                                    @NotNull
                                                                                                    Supplier<java.lang.String> messageSupplier)

Checks that object reference is not null.

Type Parameters:

T - the type of the object

Parameters:

obj - an object

messageSupplier - a supplier of the detail message for NullPointerException.

Returns:

a source object if it is not null

Throws:

java.lang.NullPointerException - if object is null

Since:

1.2.0

See Also:

requireNonNull(java.lang.Object)

requireNonNullElse

@NotNull
 @Contract(value="!null, _ -> param1; null, !null -> param2; null, null -> fail",
          pure=true)
public static <T> T requireNonNullElse(@Nullable
                                                                                                                                                       T obj,
                                                                                                                                                       @NotNull
                                                                                                                                                       T defaultObj)

Returns the first object if it is non-null, returns the non-null second object otherwise.

Type Parameters:

T - the type of the objects

Parameters:

obj - an object

defaultObj - a non-null object to return if the first object is null

Returns:

the first object if it is non-null, the non-null second object otherwise.

Since:

1.2.0

requireNonNullElseGet

@NotNull
 @Contract(value="!null, _ -> param1; null, null -> fail")
public static <T> T requireNonNullElseGet(@Nullable
                                                                                                              T obj,
                                                                                                              @NotNull
                                                                                                              Supplier<? extends T> supplier)

Returns the first object if it is non-null, returns the non-null supplier's result otherwise.

Type Parameters:

T - the type of the first object and return type

Parameters:

obj - an object

supplier - a supplier to return non-null object if first object is null

Returns:

the first object if it is non-null, the non-null supplier's result otherwise

Since:

1.2.0

requireNonNullElements

@NotNull
 @Contract(value="null -> fail; !null -> param1")
public static <T> java.util.Collection<T> requireNonNullElements(@NotNull
                                                                                                                            java.util.Collection<T> collection)

Checks that collection and its elements are non-null.

Type Parameters:

T - the type of the objects in the collection

Parameters:

collection - a collection to be checked for non-null elements

Returns:

a collection

Throws:

java.lang.NullPointerException - if collection or its elements are null

Since:

1.2.0

isNull

@Contract(value="null -> true; !null -> false",
          pure=true)
public static boolean isNull(@Nullable
                                                                                                  java.lang.Object obj)

Checks that object reference is null.

Parameters:

obj - an object

Returns:

true if the object reference is null, false otherwise

Since:

1.2.0

See Also:

Predicate

nonNull

@Contract(value="null -> false; !null -> true",
          pure=true)
public static boolean nonNull(@Nullable
                                                                                                   java.lang.Object obj)

Checks that object reference is not null.

Parameters:

obj - an object

Returns:

false if the object reference is null, true otherwise

Since:

1.2.0

See Also:

Predicate, Predicate.Util#notNull()