public abstract class

ObjectUtils

extends Object
java.lang.Object
   ↳ org.springframework.util.ObjectUtils

Class Overview

Miscellaneous object utility methods.

Mainly for internal use within the framework; consider Jakarta's Commons Lang for a more comprehensive suite of object utilities.

Thanks to Alex Ruiz for contributing several enhancements to this class!

See Also
  • org.apache.commons.lang.ObjectUtils

Summary

Public Constructors
ObjectUtils()
Public Methods
static <A, O extends A> A[] addObjectToArray(A[] array, O obj)
Append the given object to the given array, returning a new array consisting of the input array contents plus the given object.
static <E extends Enum<?>> E caseInsensitiveValueOf(E[] enumValues, String constant)
Case insensitive alternative to valueOf(Class, String).
static boolean containsConstant(Enum[]<?> enumValues, String constant, boolean caseSensitive)
Check whether the given array of enum constants contains a constant with the given name.
static boolean containsConstant(Enum[]<?> enumValues, String constant)
Check whether the given array of enum constants contains a constant with the given name, ignoring case when determining a match.
static boolean containsElement(Object[] array, Object element)
Check whether the given array contains the given element.
static String getDisplayString(Object obj)
Return a content-based String representation if obj is not null; otherwise returns an empty String.
static String getIdentityHexString(Object obj)
Return a hex String form of an object's identity hash code.
static int hashCode(long lng)
Return the same value as hashCode().
static int hashCode(boolean bool)
Return the same value as hashCode().
static int hashCode(double dbl)
Return the same value as hashCode().
static int hashCode(float flt)
Return the same value as hashCode().
static String identityToString(Object obj)
Return a String representation of an object's overall identity.
static boolean isArray(Object obj)
Determine whether the given object is an array: either an Object array or a primitive array.
static boolean isCheckedException(Throwable ex)
Return whether the given throwable is a checked exception: that is, neither a RuntimeException nor an Error.
static boolean isCompatibleWithThrowsClause(Throwable ex, Class[] declaredExceptions)
Check whether the given exception is compatible with the exceptions declared in a throws clause.
static boolean isEmpty(Object[] array)
Determine whether the given array is empty: i.e.
static String nullSafeClassName(Object obj)
Determine the class name for the given object.
static boolean nullSafeEquals(Object o1, Object o2)
Determine if the given objects are equal, returning true if both are null or false if only one is null.
static int nullSafeHashCode(byte[] array)
Return a hash code based on the contents of the specified array.
static int nullSafeHashCode(long[] array)
Return a hash code based on the contents of the specified array.
static int nullSafeHashCode(Object obj)
Return as hash code for the given object; typically the value of hashCode().
static int nullSafeHashCode(int[] array)
Return a hash code based on the contents of the specified array.
static int nullSafeHashCode(float[] array)
Return a hash code based on the contents of the specified array.
static int nullSafeHashCode(boolean[] array)
Return a hash code based on the contents of the specified array.
static int nullSafeHashCode(double[] array)
Return a hash code based on the contents of the specified array.
static int nullSafeHashCode(short[] array)
Return a hash code based on the contents of the specified array.
static int nullSafeHashCode(Object[] array)
Return a hash code based on the contents of the specified array.
static int nullSafeHashCode(char[] array)
Return a hash code based on the contents of the specified array.
static String nullSafeToString(char[] array)
Return a String representation of the contents of the specified array.
static String nullSafeToString(int[] array)
Return a String representation of the contents of the specified array.
static String nullSafeToString(boolean[] array)
Return a String representation of the contents of the specified array.
static String nullSafeToString(byte[] array)
Return a String representation of the contents of the specified array.
static String nullSafeToString(Object[] array)
Return a String representation of the contents of the specified array.
static String nullSafeToString(long[] array)
Return a String representation of the contents of the specified array.
static String nullSafeToString(double[] array)
Return a String representation of the contents of the specified array.
static String nullSafeToString(short[] array)
Return a String representation of the contents of the specified array.
static String nullSafeToString(float[] array)
Return a String representation of the contents of the specified array.
static String nullSafeToString(Object obj)
Return a String representation of the specified Object.
static Object[] toObjectArray(Object source)
Convert the given array (which may be a primitive array) to an object array (if necessary of primitive wrapper objects).
[Expand]
Inherited Methods
From class java.lang.Object

Public Constructors

public ObjectUtils ()

Also: SpringCore

Public Methods

public static A[] addObjectToArray (A[] array, O obj)

Also: SpringCore

Append the given object to the given array, returning a new array consisting of the input array contents plus the given object.

Parameters
array the array to append to (can be null)
obj the object to append
Returns
  • the new array (of the same component type; never null)

public static E caseInsensitiveValueOf (E[] enumValues, String constant)

Also: SpringCore

Case insensitive alternative to valueOf(Class, String).

Parameters
enumValues the array of all Enum constants in question, usually per Enum.values()
constant the constant to get the enum value of
Throws
IllegalArgumentException if the given constant is not found in the given array of enum values. Use containsConstant(Enum[], String) as a guard to avoid this exception.

public static boolean containsConstant (Enum[]<?> enumValues, String constant, boolean caseSensitive)

Also: SpringCore

Check whether the given array of enum constants contains a constant with the given name.

Parameters
enumValues the enum values to check, typically the product of a call to MyEnum.values()
constant the constant name to find (must not be null or empty string)
caseSensitive whether case is significant in determining a match
Returns
  • whether the constant has been found in the given array

public static boolean containsConstant (Enum[]<?> enumValues, String constant)

Also: SpringCore

Check whether the given array of enum constants contains a constant with the given name, ignoring case when determining a match.

Parameters
enumValues the enum values to check, typically the product of a call to MyEnum.values()
constant the constant name to find (must not be null or empty string)
Returns
  • whether the constant has been found in the given array

public static boolean containsElement (Object[] array, Object element)

Also: SpringCore

Check whether the given array contains the given element.

Parameters
array the array to check (may be null, in which case the return value will always be false)
element the element to check for
Returns
  • whether the element has been found in the given array

public static String getDisplayString (Object obj)

Also: SpringCore

Return a content-based String representation if obj is not null; otherwise returns an empty String.

Differs from nullSafeToString(Object) in that it returns an empty String rather than "null" for a null value.

Parameters
obj the object to build a display String for
Returns
  • a display String representation of obj

public static String getIdentityHexString (Object obj)

Also: SpringCore

Return a hex String form of an object's identity hash code.

Parameters
obj the object
Returns
  • the object's identity code in hex notation

public static int hashCode (long lng)

Also: SpringCore

Return the same value as hashCode().

See Also

public static int hashCode (boolean bool)

Also: SpringCore

Return the same value as hashCode().

See Also

public static int hashCode (double dbl)

Also: SpringCore

Return the same value as hashCode().

See Also

public static int hashCode (float flt)

Also: SpringCore

Return the same value as hashCode().

See Also

public static String identityToString (Object obj)

Also: SpringCore

Return a String representation of an object's overall identity.

Parameters
obj the object (may be null)
Returns
  • the object's identity as String representation, or an empty String if the object was null

public static boolean isArray (Object obj)

Also: SpringCore

Determine whether the given object is an array: either an Object array or a primitive array.

Parameters
obj the object to check

public static boolean isCheckedException (Throwable ex)

Also: SpringCore

Return whether the given throwable is a checked exception: that is, neither a RuntimeException nor an Error.

Parameters
ex the throwable to check
Returns
  • whether the throwable is a checked exception
See Also

public static boolean isCompatibleWithThrowsClause (Throwable ex, Class[] declaredExceptions)

Also: SpringCore

Check whether the given exception is compatible with the exceptions declared in a throws clause.

Parameters
ex the exception to checked
declaredExceptions the exceptions declared in the throws clause
Returns
  • whether the given exception is compatible

public static boolean isEmpty (Object[] array)

Also: SpringCore

Determine whether the given array is empty: i.e. null or of zero length.

Parameters
array the array to check

public static String nullSafeClassName (Object obj)

Also: SpringCore

Determine the class name for the given object.

Returns "null" if obj is null.

Parameters
obj the object to introspect (may be null)
Returns
  • the corresponding class name

public static boolean nullSafeEquals (Object o1, Object o2)

Also: SpringCore

Determine if the given objects are equal, returning true if both are null or false if only one is null.

Compares arrays with Arrays.equals, performing an equality check based on the array elements rather than the array reference.

Parameters
o1 first Object to compare
o2 second Object to compare
Returns
  • whether the given objects are equal

public static int nullSafeHashCode (byte[] array)

Also: SpringCore

Return a hash code based on the contents of the specified array. If array is null, this method returns 0.

public static int nullSafeHashCode (long[] array)

Also: SpringCore

Return a hash code based on the contents of the specified array. If array is null, this method returns 0.

public static int nullSafeHashCode (Object obj)

Also: SpringCore

Return as hash code for the given object; typically the value of hashCode(). If the object is an array, this method will delegate to any of the nullSafeHashCode methods for arrays in this class. If the object is null, this method returns 0.

public static int nullSafeHashCode (int[] array)

Also: SpringCore

Return a hash code based on the contents of the specified array. If array is null, this method returns 0.

public static int nullSafeHashCode (float[] array)

Also: SpringCore

Return a hash code based on the contents of the specified array. If array is null, this method returns 0.

public static int nullSafeHashCode (boolean[] array)

Also: SpringCore

Return a hash code based on the contents of the specified array. If array is null, this method returns 0.

public static int nullSafeHashCode (double[] array)

Also: SpringCore

Return a hash code based on the contents of the specified array. If array is null, this method returns 0.

public static int nullSafeHashCode (short[] array)

Also: SpringCore

Return a hash code based on the contents of the specified array. If array is null, this method returns 0.

public static int nullSafeHashCode (Object[] array)

Also: SpringCore

Return a hash code based on the contents of the specified array. If array is null, this method returns 0.

public static int nullSafeHashCode (char[] array)

Also: SpringCore

Return a hash code based on the contents of the specified array. If array is null, this method returns 0.

public static String nullSafeToString (char[] array)

Also: SpringCore

Return a String representation of the contents of the specified array.

The String representation consists of a list of the array's elements, enclosed in curly braces ("{}"). Adjacent elements are separated by the characters ", " (a comma followed by a space). Returns "null" if array is null.

Parameters
array the array to build a String representation for
Returns
  • a String representation of array

public static String nullSafeToString (int[] array)

Also: SpringCore

Return a String representation of the contents of the specified array.

The String representation consists of a list of the array's elements, enclosed in curly braces ("{}"). Adjacent elements are separated by the characters ", " (a comma followed by a space). Returns "null" if array is null.

Parameters
array the array to build a String representation for
Returns
  • a String representation of array

public static String nullSafeToString (boolean[] array)

Also: SpringCore

Return a String representation of the contents of the specified array.

The String representation consists of a list of the array's elements, enclosed in curly braces ("{}"). Adjacent elements are separated by the characters ", " (a comma followed by a space). Returns "null" if array is null.

Parameters
array the array to build a String representation for
Returns
  • a String representation of array

public static String nullSafeToString (byte[] array)

Also: SpringCore

Return a String representation of the contents of the specified array.

The String representation consists of a list of the array's elements, enclosed in curly braces ("{}"). Adjacent elements are separated by the characters ", " (a comma followed by a space). Returns "null" if array is null.

Parameters
array the array to build a String representation for
Returns
  • a String representation of array

public static String nullSafeToString (Object[] array)

Also: SpringCore

Return a String representation of the contents of the specified array.

The String representation consists of a list of the array's elements, enclosed in curly braces ("{}"). Adjacent elements are separated by the characters ", " (a comma followed by a space). Returns "null" if array is null.

Parameters
array the array to build a String representation for
Returns
  • a String representation of array

public static String nullSafeToString (long[] array)

Also: SpringCore

Return a String representation of the contents of the specified array.

The String representation consists of a list of the array's elements, enclosed in curly braces ("{}"). Adjacent elements are separated by the characters ", " (a comma followed by a space). Returns "null" if array is null.

Parameters
array the array to build a String representation for
Returns
  • a String representation of array

public static String nullSafeToString (double[] array)

Also: SpringCore

Return a String representation of the contents of the specified array.

The String representation consists of a list of the array's elements, enclosed in curly braces ("{}"). Adjacent elements are separated by the characters ", " (a comma followed by a space). Returns "null" if array is null.

Parameters
array the array to build a String representation for
Returns
  • a String representation of array

public static String nullSafeToString (short[] array)

Also: SpringCore

Return a String representation of the contents of the specified array.

The String representation consists of a list of the array's elements, enclosed in curly braces ("{}"). Adjacent elements are separated by the characters ", " (a comma followed by a space). Returns "null" if array is null.

Parameters
array the array to build a String representation for
Returns
  • a String representation of array

public static String nullSafeToString (float[] array)

Also: SpringCore

Return a String representation of the contents of the specified array.

The String representation consists of a list of the array's elements, enclosed in curly braces ("{}"). Adjacent elements are separated by the characters ", " (a comma followed by a space). Returns "null" if array is null.

Parameters
array the array to build a String representation for
Returns
  • a String representation of array

public static String nullSafeToString (Object obj)

Also: SpringCore

Return a String representation of the specified Object.

Builds a String representation of the contents in case of an array. Returns "null" if obj is null.

Parameters
obj the object to build a String representation for
Returns
  • a String representation of obj

public static Object[] toObjectArray (Object source)

Also: SpringCore

Convert the given array (which may be a primitive array) to an object array (if necessary of primitive wrapper objects).

A null source value will be converted to an empty Object array.

Parameters
source the (potentially primitive) array
Returns
  • the corresponding object array (never null)
Throws
IllegalArgumentException if the parameter is not an array