org.springframework.shell.support.util
Class ObjectUtils

java.lang.Object
  org.springframework.shell.support.util.ObjectUtils

public final class ObjectUtils
extends Object

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

See Also:

org.apache.commons.lang.ObjectUtils

Method Summary

static Object[]	addObjectToArray(Object[] array, Object obj) Append the given Object to the given array, returning a new array consisting of the input array contents plus the given Object.
static boolean	containsElement(Object[] array, Object element) Check whether the given array contains the given element.
static <T> T	defaultIfNull(T object, T defaultValue) Returns the given object if not null, otherwise the given default value
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(boolean bool) Returns the hash code of the given boolean value.
static int	hashCode(double dbl) Return the same value as Double.hashCode().
static int	hashCode(float flt) Return the same value as Float.hashCode().
static int	hashCode(long lng) Return the same value as Long.hashCode().
static String	identityToString(Object obj) Return a String representation of an object's overall identity.
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) Return whether the given array is empty: that is, null or of zero length.
static String	nullSafeClassName(Object obj) Determine the class name for the given object.
static <T> int	nullSafeComparison(Comparable<T> one, T other) Compares the two given objects, with null equivalent to null and null "less than" any non-null instance.
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(boolean... array) Return a hash code based on the contents of the specified array.
static int	nullSafeHashCode(byte... 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 int	nullSafeHashCode(double... 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(int... 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... 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 Object.hashCode().
static int	nullSafeHashCode(short... array) Return a hash code based on 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(char... 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(float... 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(long... 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(Object obj) Return a String representation of the specified Object.
static String	nullSafeToString(short... array) Return a String representation of the contents of the specified array.
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).
static String	toString(Object object, String defaultValue) Returns the String representation of the given object, or if it's null, the given default string

Methods inherited from class java.lang.Object

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

Method Detail

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<?>... declaredExceptions)

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

isEmpty

public static boolean isEmpty(Object[] array)

Return whether the given array is empty: that is, null or of zero length.

Parameters:

array - the array to check

Returns:

whether the given array is empty

containsElement

public static boolean containsElement(Object[] array,
                                      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

addObjectToArray

public static Object[] addObjectToArray(Object[] array,
                                        Object 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)

toObjectArray

public 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).

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

nullSafeEquals

public 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.

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:

Arrays.equals(long[], long[])

nullSafeHashCode

public static int nullSafeHashCode(Object obj)

Return as hash code for the given object; typically the value of Object.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.

See Also:

nullSafeHashCode(Object[]), nullSafeHashCode(boolean[]), nullSafeHashCode(byte[]), nullSafeHashCode(char[]), nullSafeHashCode(double[]), nullSafeHashCode(float[]), nullSafeHashCode(int[]), nullSafeHashCode(long[]), nullSafeHashCode(short[])

nullSafeHashCode

public static int nullSafeHashCode(Object... array)

Return a hash code based on the contents of the specified array.

Parameters:

array - the array from whose elements to calculate the hash code (can be null)

Returns:

0 if the array is null

nullSafeHashCode

public static int nullSafeHashCode(boolean... array)

Return a hash code based on the contents of the specified array.

Parameters:

array - can be null

Returns:

0 if array is null

nullSafeHashCode

public static int nullSafeHashCode(byte... array)

Return a hash code based on the contents of the specified array.

Parameters:

array - can be null

Returns:

0 if array is null

nullSafeHashCode

public static int nullSafeHashCode(char... array)

Return a hash code based on the contents of the specified array.

Parameters:

array - can be null

Returns:

0 if array is null

nullSafeHashCode

public static int nullSafeHashCode(double... array)

Return a hash code based on the contents of the specified array.

Parameters:

array - can be null

Returns:

0 if array is null

nullSafeHashCode

public static int nullSafeHashCode(float... array)

Return a hash code based on the contents of the specified array.

Parameters:

array - can be null

Returns:

0 if array is null

nullSafeHashCode

public static int nullSafeHashCode(int... array)

Return a hash code based on the contents of the specified array.

Parameters:

array - can be null

Returns:

0 if array is null

nullSafeHashCode

public static int nullSafeHashCode(long... array)

Return a hash code based on the contents of the specified array.

Parameters:

array - can be null

Returns:

0 if array is null

nullSafeHashCode

public static int nullSafeHashCode(short... array)

Return a hash code based on the contents of the specified array.

Parameters:

array - can be null

Returns:

0 if array is null

hashCode

public static int hashCode(boolean bool)

Returns the hash code of the given boolean value.

Parameters:

bool - the boolean for which to return the hash code

Returns:

see Boolean.hashCode()

hashCode

public static int hashCode(double dbl)

Return the same value as Double.hashCode().

See Also:

Double.hashCode()

hashCode

public static int hashCode(float flt)

Return the same value as Float.hashCode().

See Also:

Float.hashCode()

hashCode

public static int hashCode(long lng)

Return the same value as Long.hashCode().

See Also:

Long.hashCode()

identityToString

public static String identityToString(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(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(Object obj)

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

nullSafeToString

public static String nullSafeToString(Object obj)

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

nullSafeToString

public static String nullSafeToString(Object... 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 "null" 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... 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 "null" 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... 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 "null" 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... 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 "null" 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... 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 "null" 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... 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 "null" 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... 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 "null" 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... 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 "null" 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... 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 "null" if array is null.

Parameters:

array - the array to build a String representation for

Returns:

a String representation of array

nullSafeComparison

public static <T> int nullSafeComparison(Comparable<T> one,
                                         T other)

Compares the two given objects, with null equivalent to null and null "less than" any non-null instance. Two non-null instances are compared using the first one's Comparable.compareTo(Object) method.

Type Parameters:

T - the type of objects being compared

Parameters:

one - the first object being compared (can be null)

other - the second object being compared (can be null)

Returns:

see Comparable.compareTo(Object)

Since:

1.2.0

toString

public static String toString(Object object,
                              String defaultValue)

Returns the String representation of the given object, or if it's null, the given default string

Parameters:

object - the object to represent as a String (can be null)

defaultValue - the value to return if the given object is null (can itself be blank)

Returns:

see above

Since:

1.2.0

defaultIfNull

public static <T> T defaultIfNull(T object,
                                  T defaultValue)

Returns the given object if not null, otherwise the given default value

Type Parameters:

T - the type of object being defaulted

Parameters:

object - the object to check (can be null)

defaultValue - the default value (can be null)

Returns:

null iff both values are null

Since:

1.2.0