java.lang.Object

org.springframework.util.ObjectUtils

public abstract class ObjectUtils extends Object

Miscellaneous object utility methods.

Mainly for internal use within the framework.

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

Since:

19.03.2004

Author:

Juergen Hoeller, Keith Donald, Rod Johnson, Rob Harrop, Chris Beams, Sam Brannen

See Also:

Constructor Summary

Constructors

Constructor

Description

ObjectUtils()
Method Summary

Modifier and Type

Method

Description

static <A, O extends A> A[]

addObjectToArray(A @Nullable [] array, @Nullable 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 <A, O extends A> @Nullable A[]

addObjectToArray(A @Nullable [] array, @Nullable O obj, int position)

Add the given object to the given array at the specified position, 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 Enum.valueOf(Class, String).

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

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

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

static boolean

containsElement(@Nullable Object @Nullable [] array, @Nullable Object element)

Check whether the given array contains the given element.

static String

getDisplayString(@Nullable 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 String

identityToString(@Nullable Object obj)

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

static boolean

isArray(@Nullable 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<?> @Nullable ... declaredExceptions)

Check whether the given exception is compatible with the specified exception types, as declared in a throws clause.

static boolean

isEmpty(@Nullable Object obj)

Determine whether the given object is empty.

static boolean

isEmpty(@Nullable Object @Nullable [] array)

Determine whether the given array is empty: i.e.

static String

nullSafeClassName(@Nullable Object obj)

Determine the class name for the given object.

static String

nullSafeConciseToString(@Nullable Object obj)

Generate a null-safe, concise string representation of the supplied object as described below.

static boolean

nullSafeEquals(@Nullable Object o1, @Nullable Object o2)

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

static int

nullSafeHash(@Nullable Object @Nullable ... elements)

Return a hash code for the given elements, delegating to nullSafeHashCode(Object) for each element.

static int

nullSafeHashCode(boolean @Nullable [] array)

Deprecated.
as of 6.1 in favor of Arrays.hashCode(boolean[])

static int

nullSafeHashCode(byte @Nullable [] array)

Deprecated.
as of 6.1 in favor of Arrays.hashCode(byte[])

static int

nullSafeHashCode(char @Nullable [] array)

Deprecated.
as of 6.1 in favor of Arrays.hashCode(char[])

static int

nullSafeHashCode(double @Nullable [] array)

Deprecated.
as of 6.1 in favor of Arrays.hashCode(double[])

static int

nullSafeHashCode(float @Nullable [] array)

Deprecated.
as of 6.1 in favor of Arrays.hashCode(float[])

static int

nullSafeHashCode(int @Nullable [] array)

Deprecated.
as of 6.1 in favor of Arrays.hashCode(int[])

static int

nullSafeHashCode(long @Nullable [] array)

Deprecated.
as of 6.1 in favor of Arrays.hashCode(long[])

static int

nullSafeHashCode(short @Nullable [] array)

Deprecated.
as of 6.1 in favor of Arrays.hashCode(short[])

static int

nullSafeHashCode(@Nullable Object obj)

Return a hash code for the given object, typically the value of Object.hashCode().

static int

nullSafeHashCode(Object @Nullable [] array)

Deprecated.
as of 6.1 in favor of Arrays.hashCode(Object[])

static String

nullSafeToString(boolean @Nullable [] array)

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

static String

nullSafeToString(byte @Nullable [] array)

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

static String

nullSafeToString(char @Nullable [] array)

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

static String

nullSafeToString(double @Nullable [] array)

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

static String

nullSafeToString(float @Nullable [] array)

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

static String

nullSafeToString(int @Nullable [] array)

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

static String

nullSafeToString(long @Nullable [] array)

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

static String

nullSafeToString(short @Nullable [] array)

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

static String

nullSafeToString(@Nullable Object obj)

Return a String representation of the specified Object.

static String

nullSafeToString(@Nullable Object @Nullable [] array)

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

static Object[]

toObjectArray(@Nullable Object source)

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

static @Nullable Object

unwrapOptional(@Nullable Object obj)

Unwrap the given object which is potentially a Optional.

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
- isCheckedException
  public static boolean isCheckedException(Throwable ex)
  
  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:
  
  Exception
  
  RuntimeException
  
  Error
- isCompatibleWithThrowsClause
  
  public static boolean isCompatibleWithThrowsClause(Throwable ex, Class<?> @Nullable ... declaredExceptions)
  
  Check whether the given exception is compatible with the specified exception types, as declared in a throws clause.
  
  Parameters:
  
  ex - the exception to check
  
  declaredExceptions - the exception types declared in the throws clause
  
  Returns:
  
  whether the given exception is compatible
- isArray
  
  @Contract("null -> false") public static boolean isArray(@Nullable Object obj)
  
  Determine whether the given object is an array: either an Object array or a primitive array.
  
  Parameters:
  
  obj - the object to check
- isEmpty
  @Contract("null -> true") public static boolean isEmpty(@Nullable Object @Nullable [] array)
  
  Determine whether the given array is empty: i.e. null or of zero length.
  
  Parameters:
  
  array - the array to check
  
  See Also:
  
  isEmpty(Object)
- isEmpty
  @Contract("null -> true") public static boolean isEmpty(@Nullable Object obj)
  
  Determine whether the given object is empty.
  This method supports the following object types.
  
  Optional: considered empty if not Optional.isPresent()
  
  Array: considered empty if its length is zero
  
  CharSequence: considered empty if its length is zero
  
  Collection: delegates to Collection.isEmpty()
  
  Map: delegates to Map.isEmpty()
  
  If the given object is non-null and not one of the aforementioned supported types, this method returns false.
  
  Parameters:
  
  obj - the object to check
  
  Returns:
  
  true if the object is null or empty
  
  Since:
  
  4.2
  
  See Also:
  
  Optional.isPresent()
  
  isEmpty(Object[])
  
  StringUtils.hasLength(CharSequence)
  
  CollectionUtils.isEmpty(java.util.Collection)
  
  CollectionUtils.isEmpty(java.util.Map)
- unwrapOptional
  
  @Contract("null -> null") public static @Nullable Object unwrapOptional(@Nullable Object obj)
  
  Unwrap the given object which is potentially a Optional.
  
  Parameters:
  
  obj - the candidate object
  
  Returns:
  
  either the value held within the Optional, null if the Optional is empty, or simply the given object as-is
  
  Since:
  
  5.0
- containsElement
  
  @Contract("null, _ -> false") public static boolean containsElement(@Nullable Object @Nullable [] array, @Nullable Object element)
  
  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
- containsConstant
  
  public 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.
  
  Parameters:
  
  enumValues - the enum values to check, typically obtained via 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
- containsConstant
  
  public static boolean containsConstant(Enum<?>[] enumValues, String constant, boolean caseSensitive)
  
  Check whether the given array of enum constants contains a constant with the given name.
  
  Parameters:
  
  enumValues - the enum values to check, typically obtained via 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
- caseInsensitiveValueOf
  
  public static <E extends Enum<?>> E caseInsensitiveValueOf(E[] enumValues, String constant)
  
  Case insensitive alternative to Enum.valueOf(Class, String).
  
  Type Parameters:
  
  E - the concrete Enum type
  
  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.
- addObjectToArray
  
  public static <A, O extends A> A[] addObjectToArray(A @Nullable [] array, @Nullable O obj)
  
  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)
- addObjectToArray
  
  public static <A, O extends A> @Nullable A[] addObjectToArray(A @Nullable [] array, @Nullable O obj, int position)
  
  Add the given object to the given array at the specified position, returning a new array consisting of the input array contents plus the given object.
  
  Parameters:
  
  array - the array to add to (can be null)
  
  obj - the object to append
  
  position - the position at which to add the object
  
  Returns:
  
  the new array (of the same component type; never null)
  
  Since:
  
  6.0
- toObjectArray
  
  public static Object[] toObjectArray(@Nullable Object source)
  
  Convert the given array (which may be a primitive array) to an object array (if necessary, to an array of primitive wrapper objects).
  A null source value or empty primitive array 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
- nullSafeEquals
  @Contract("null, null -> true; null, _ -> false; _, null -> false") public static boolean nullSafeEquals(@Nullable Object o1, @Nullable Object o2)
  
  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
  
  See Also:
  
  Object.equals(Object)
  
  Arrays.equals(long[], long[])
- nullSafeHash
  
  public static int nullSafeHash(@Nullable Object @Nullable ... elements)
  
  Return a hash code for the given elements, delegating to nullSafeHashCode(Object) for each element. Contrary to Objects.hash(Object...), this method can handle an element that is an array.
  
  Parameters:
  
  elements - the elements to be hashed
  
  Returns:
  
  a hash value of the elements
  
  Since:
  
  6.1
- nullSafeHashCode
  public static int nullSafeHashCode(@Nullable Object obj)
  
  Return a hash code for the given object, typically the value of Object.hashCode(). If the object is an array, this method will delegate to one of the Arrays.hashCode methods. If the object is null, this method returns 0.
  
  See Also:
  
  Object.hashCode()
  
  Arrays
- nullSafeHashCode
  
  @Deprecated(since="6.1") public static int nullSafeHashCode(Object @Nullable [] array)
  
  Deprecated.
  as of 6.1 in favor of Arrays.hashCode(Object[])
  
  Return a hash code based on the contents of the specified array. If array is null, this method returns 0.
- nullSafeHashCode
  
  @Deprecated(since="6.1") public static int nullSafeHashCode(boolean @Nullable [] array)
  
  Deprecated.
  as of 6.1 in favor of Arrays.hashCode(boolean[])
  
  Return a hash code based on the contents of the specified array. If array is null, this method returns 0.
- nullSafeHashCode
  
  @Deprecated(since="6.1") public static int nullSafeHashCode(byte @Nullable [] array)
  
  Deprecated.
  as of 6.1 in favor of Arrays.hashCode(byte[])
  
  Return a hash code based on the contents of the specified array. If array is null, this method returns 0.
- nullSafeHashCode
  
  @Deprecated(since="6.1") public static int nullSafeHashCode(char @Nullable [] array)
  
  Deprecated.
  as of 6.1 in favor of Arrays.hashCode(char[])
  
  Return a hash code based on the contents of the specified array. If array is null, this method returns 0.
- nullSafeHashCode
  
  @Deprecated(since="6.1") public static int nullSafeHashCode(double @Nullable [] array)
  
  Deprecated.
  as of 6.1 in favor of Arrays.hashCode(double[])
  
  Return a hash code based on the contents of the specified array. If array is null, this method returns 0.
- nullSafeHashCode
  
  @Deprecated(since="6.1") public static int nullSafeHashCode(float @Nullable [] array)
  
  Deprecated.
  as of 6.1 in favor of Arrays.hashCode(float[])
  
  Return a hash code based on the contents of the specified array. If array is null, this method returns 0.
- nullSafeHashCode
  
  @Deprecated(since="6.1") public static int nullSafeHashCode(int @Nullable [] array)
  
  Deprecated.
  as of 6.1 in favor of Arrays.hashCode(int[])
  
  Return a hash code based on the contents of the specified array. If array is null, this method returns 0.
- nullSafeHashCode
  
  @Deprecated(since="6.1") public static int nullSafeHashCode(long @Nullable [] array)
  
  Deprecated.
  as of 6.1 in favor of Arrays.hashCode(long[])
  
  Return a hash code based on the contents of the specified array. If array is null, this method returns 0.
- nullSafeHashCode
  
  @Deprecated(since="6.1") public static int nullSafeHashCode(short @Nullable [] array)
  
  Deprecated.
  as of 6.1 in favor of Arrays.hashCode(short[])
  
  Return a hash code based on the contents of the specified array. If array is null, this method returns 0.
- identityToString
  
  public static String identityToString(@Nullable Object obj)
  
  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
- getIdentityHexString
  
  public static String getIdentityHexString(Object obj)
  
  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
- getDisplayString
  public static String getDisplayString(@Nullable Object obj)
  
  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
  
  See Also:
  
  nullSafeToString(Object)
- nullSafeClassName
  
  public static String nullSafeClassName(@Nullable Object obj)
  
  Determine the class name for the given object.
  Returns a "null" String if obj is null.
  
  Parameters:
  
  obj - the object to introspect (may be null)
  
  Returns:
  
  the corresponding class name
- nullSafeToString
  public static String nullSafeToString(@Nullable Object obj)
  
  Return a String representation of the specified Object.
  Builds a String representation of the contents in case of an array. Returns a "null" String if obj is null.
  
  Parameters:
  
  obj - the object to build a String representation for
  
  Returns:
  
  a String representation of obj
  
  See Also:
  
  nullSafeConciseToString(Object)
- nullSafeToString
  
  public static String nullSafeToString(@Nullable Object @Nullable [] array)
  
  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 a "null" String if array is null.
  
  Parameters:
  
  array - the array to build a String representation for
  
  Returns:
  
  a String representation of array
- nullSafeToString
  
  public static String nullSafeToString(boolean @Nullable [] array)
  
  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 a "null" String if array is null.
  
  Parameters:
  
  array - the array to build a String representation for
  
  Returns:
  
  a String representation of array
- nullSafeToString
  
  public static String nullSafeToString(byte @Nullable [] array)
  
  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 a "null" String if array is null.
  
  Parameters:
  
  array - the array to build a String representation for
  
  Returns:
  
  a String representation of array
- nullSafeToString
  
  public static String nullSafeToString(char @Nullable [] array)
  
  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 a "null" String if array is null.
  
  Parameters:
  
  array - the array to build a String representation for
  
  Returns:
  
  a String representation of array
- nullSafeToString
  
  public static String nullSafeToString(double @Nullable [] array)
  
  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 a "null" String if array is null.
  
  Parameters:
  
  array - the array to build a String representation for
  
  Returns:
  
  a String representation of array
- nullSafeToString
  
  public static String nullSafeToString(float @Nullable [] array)
  
  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 a "null" String if array is null.
  
  Parameters:
  
  array - the array to build a String representation for
  
  Returns:
  
  a String representation of array
- nullSafeToString
  
  public static String nullSafeToString(int @Nullable [] array)
  
  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 a "null" String if array is null.
  
  Parameters:
  
  array - the array to build a String representation for
  
  Returns:
  
  a String representation of array
- nullSafeToString
  
  public static String nullSafeToString(long @Nullable [] array)
  
  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 a "null" String if array is null.
  
  Parameters:
  
  array - the array to build a String representation for
  
  Returns:
  
  a String representation of array
- nullSafeToString
  
  public static String nullSafeToString(short @Nullable [] array)
  
  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 a "null" String if array is null.
  
  Parameters:
  
  array - the array to build a String representation for
  
  Returns:
  
  a String representation of array
- nullSafeConciseToString
  public static String nullSafeConciseToString(@Nullable Object obj)
  
  Generate a null-safe, concise string representation of the supplied object as described below.
  Favor this method over nullSafeToString(Object) when you need the length of the generated string to be limited.
  Returns:
  
  "null" if obj is null
  
  "Optional.empty" if obj is an empty Optional
  
  "Optional[<concise-string>]" if obj is a non-empty Optional, where <concise-string> is the result of invoking this method on the object contained in the Optional
  
  "{}" if obj is an empty array
  
  "{...}" if obj is a Map or a non-empty array
  
  "[...]" if obj is a Collection
  
  Class name if obj is a Class
  
  Charset name if obj is a Charset
  
  TimeZone ID if obj is a TimeZone
  
  Zone ID if obj is a ZoneId
  
  Potentially truncated string if obj is a String or CharSequence
  
  Potentially truncated string if obj is a simple value type whose toString() method returns a non-null value
  
  Otherwise, a string representation of the object's type name concatenated with "@" and a hex string form of the object's identity hash code
  
  In the context of this method, a simple value type is any of the following: primitive wrapper (excluding Void), Enum, Number, Date, Temporal, File, Path, URI, URL, InetAddress, Currency, Locale, UUID, Pattern.
  
  Parameters:
  
  obj - the object to build a string representation for
  
  Returns:
  
  a concise string representation of the supplied object
  
  Since:
  
  5.3.27
  
  See Also:
  
  nullSafeToString(Object)
  
  StringUtils.truncate(CharSequence)
  
  ClassUtils.isSimpleValueType(Class)

Class ObjectUtils

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Details

ObjectUtils

Method Details

isCheckedException

isCompatibleWithThrowsClause

isArray

isEmpty

isEmpty

unwrapOptional

containsElement

containsConstant

containsConstant

caseInsensitiveValueOf

addObjectToArray

addObjectToArray

toObjectArray

nullSafeEquals

nullSafeHash

nullSafeHashCode

nullSafeHashCode

nullSafeHashCode

nullSafeHashCode

nullSafeHashCode

nullSafeHashCode

nullSafeHashCode

nullSafeHashCode

nullSafeHashCode

nullSafeHashCode

identityToString

getIdentityHexString

getDisplayString

nullSafeClassName

nullSafeToString

nullSafeToString

nullSafeToString

nullSafeToString

nullSafeToString

nullSafeToString

nullSafeToString

nullSafeToString

nullSafeToString

nullSafeToString

nullSafeConciseToString