程序包 com.walker.infrastructure.utils

类 ObjectUtils

java.lang.Object

com.walker.infrastructure.utils.ObjectUtils

public abstract 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.

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

从以下版本开始:

19.03.2004 // * @see org.apache.commons.lang.ObjectUtils

作者:

Juergen Hoeller, Keith Donald, Rod Johnson, Rob Harrop

构造器概要

构造器

构造器	说明
ObjectUtils()

方法概要

修饰符和类型	方法	说明
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 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)	Return the same value as Boolean.hashCode().
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	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(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(short[] 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(Object[] 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(short[] 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(Object[] 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).

从类继承的方法 java.lang.Object

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

构造器详细资料

ObjectUtils

public ObjectUtils()

方法详细资料

isCheckedException

public static boolean isCheckedException(Throwable ex)

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

参数:

ex - the throwable to check

返回:

whether the throwable is a checked exception

另请参阅:

• 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.

参数:

ex - the exception to checked

declaredExceptions - the exceptions declared in the throws clause

返回:

whether the given exception is compatible

isArray

public static boolean isArray(Object obj)

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

参数:

obj - the object to check

isEmpty

public static boolean isEmpty(Object[] array)

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

参数:

array - the array to check

containsElement

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

Check whether the given array contains the given element.

参数:

array - the array to check (may be null, in which case the return value will always be false)

element - the element to check for

返回:

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.

参数:

array - the array to append to (can be null)

obj - the Object to append

返回:

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.

参数:

source - the (potentially primitive) array

返回:

the corresponding object array (never null)

抛出:

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.

参数:

o1 - first Object to compare

o2 - second Object to compare

返回:

whether the given objects are equal

另请参阅:

• 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.

另请参阅:

• 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. If array is null, this method returns 0.

nullSafeHashCode

public static int nullSafeHashCode(boolean[] array)

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

nullSafeHashCode

public static int nullSafeHashCode(byte[] array)

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

nullSafeHashCode

public static int nullSafeHashCode(char[] array)

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

nullSafeHashCode

public static int nullSafeHashCode(double[] array)

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

nullSafeHashCode

public static int nullSafeHashCode(float[] array)

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

nullSafeHashCode

public static int nullSafeHashCode(int[] array)

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

nullSafeHashCode

public static int nullSafeHashCode(long[] array)

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

nullSafeHashCode

public static int nullSafeHashCode(short[] array)

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

hashCode

public static int hashCode(boolean bool)

Return the same value as Boolean.hashCode().

另请参阅:

• Boolean.hashCode()

hashCode

public static int hashCode(double dbl)

Return the same value as Double.hashCode().

另请参阅:

• Double.hashCode()

hashCode

public static int hashCode(float flt)

Return the same value as Float.hashCode().

另请参阅:

• Float.hashCode()

hashCode

public static int hashCode(long lng)

Return the same value as Long.hashCode().

另请参阅:

• Long.hashCode()

identityToString

public static String identityToString(Object obj)

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

参数:

obj - the object (may be null)

返回:

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.

参数:

obj - the object

返回:

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.

参数:

obj - the object to build a display String for

返回:

a display String representation of obj

另请参阅:

• nullSafeToString(Object)

nullSafeClassName

public static String nullSafeClassName(Object obj)

Determine the class name for the given object.

Returns "null" if obj is null.

参数:

obj - the object to introspect (may be null)

返回:

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.

参数:

obj - the object to build a String representation for

返回:

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.

参数:

array - the array to build a String representation for

返回:

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.

参数:

array - the array to build a String representation for

返回:

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.

参数:

array - the array to build a String representation for

返回:

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.

参数:

array - the array to build a String representation for

返回:

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.

参数:

array - the array to build a String representation for

返回:

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.

参数:

array - the array to build a String representation for

返回:

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.

参数:

array - the array to build a String representation for

返回:

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.

参数:

array - the array to build a String representation for

返回:

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.

参数:

array - the array to build a String representation for

返回:

a String representation of array