Objects

checkFromIndexSize

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

Checks if the sub-range from fromIndex (inclusive) to fromIndex + size (exclusive) is within the bounds of range from 0 (inclusive) to length (exclusive).

The sub-range is defined to be out of bounds if any of the following inequalities is true:

• fromIndex < 0
• size < 0
• fromIndex + size > length, taking into account integer overflow
• length < 0, which is implied from the former inequalities

checkFromIndexSize

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

Checks if the sub-range from fromIndex (inclusive) to fromIndex + size (exclusive) is within the bounds of range from 0 (inclusive) to length (exclusive).

The sub-range is defined to be out of bounds if any of the following inequalities is true:

• fromIndex < 0
• size < 0
• fromIndex + size > length, taking into account integer overflow
• length < 0, which is implied from the former inequalities

checkFromToIndex

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

Checks if the sub-range from fromIndex (inclusive) to toIndex (exclusive) is within the bounds of range from 0 (inclusive) to length (exclusive).

The sub-range is defined to be out of bounds if any of the following inequalities is true:

• fromIndex < 0
• fromIndex > toIndex
• toIndex > length
• length < 0, which is implied from the former inequalities

checkFromToIndex

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

Checks if the sub-range from fromIndex (inclusive) to toIndex (exclusive) is within the bounds of range from 0 (inclusive) to length (exclusive).

The sub-range is defined to be out of bounds if any of the following inequalities is true:

• fromIndex < 0
• fromIndex > toIndex
• toIndex > length
• length < 0, which is implied from the former inequalities

checkIndex

public static long checkIndex (long index, 
                long length)

Checks if the index is within the bounds of the range from 0 (inclusive) to length (exclusive).

The index is defined to be out of bounds if any of the following inequalities is true:

• index < 0
• index >= length
• length < 0, which is implied from the former inequalities

checkIndex

public static int checkIndex (int index, 
                int length)

Checks if the index is within the bounds of the range from 0 (inclusive) to length (exclusive).

The index is defined to be out of bounds if any of the following inequalities is true:

• index < 0
• index >= length
• length < 0, which is implied from the former inequalities

compare

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

Returns 0 if the arguments are identical and c.compare(a, b) otherwise. Consequently, if both arguments are null 0 is returned.

Note that if one of the arguments is null, a NullPointerException may or may not be thrown depending on what ordering policy, if any, the Comparator chooses to have for null values.

deepEquals

public static boolean deepEquals (Object a, 
                Object b)

Returns true if the arguments are deeply equal to each other and false otherwise. Two null values are deeply equal. If both arguments are arrays, the algorithm in Arrays.deepEquals is used to determine equality. Otherwise, equality is determined by using the equals method of the first argument.

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. Otherwise, if the first argument is not null, equality is determined by calling the equals method of the first argument with the second argument of this method. Otherwise, false is returned.

hash

public static int hash (Object... values)

Generates a hash code for a sequence of input values. The hash code is generated as if all the input values were placed into an array, and that array were hashed by calling Arrays.hashCode(java.lang.Object[]).

This method is useful for implementing Object.hashCode() on objects containing multiple fields. For example, if an object that has three fields, x, y, and z, one could write:

 @Override public int hashCode() {
     return Objects.hash(x, y, z);
 }
 

hashCode

public static int hashCode (Object o)

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

isNull

public static boolean isNull (Object obj)

Returns true if the provided reference is null otherwise returns false.

nonNull

public static boolean nonNull (Object obj)

Returns true if the provided reference is non-null otherwise returns false.

requireNonNull

public static T requireNonNull (T obj, 
                String message)

Checks that the specified object reference is not null and throws a customized NullPointerException if it is. This method is designed primarily for doing parameter validation in methods and constructors with multiple parameters, as demonstrated below:

 public Foo(Bar bar, Baz baz) {
     this.bar = Objects.requireNonNull(bar, "bar must not be null");
     this.baz = Objects.requireNonNull(baz, "baz must not be null");
 }
 

requireNonNull

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

Checks that the specified object reference is not null and throws a customized NullPointerException if it is.

Unlike the method requireNonNull(java.lang.Object, java.lang.String), this method allows creation of the message to be deferred until after the null check is made. While this may confer a performance advantage in the non-null case, when deciding to call this method care should be taken that the costs of creating the message supplier are less than the cost of just creating the string message directly.

requireNonNull

public static T requireNonNull (T obj)

Checks that the specified object reference is not null. This method is designed primarily for doing parameter validation in methods and constructors, as demonstrated below:

 public Foo(Bar bar) {
     this.bar = Objects.requireNonNull(bar);
 }
 

requireNonNullElse

public static T requireNonNullElse (T obj, 
                T defaultObj)

Returns the first argument if it is non-null and otherwise returns the non-null second argument.

requireNonNullElseGet

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

Returns the first argument if it is non-null and otherwise returns the non-null value of supplier.get().

toString

public static String toString (Object o)

Returns the result of calling toString for a non-null argument and "null" for a null argument.

toString

public static String toString (Object o, 
                String nullDefault)

Returns the result of calling toString on the first argument if the first argument is not null and returns the second argument otherwise.