类 AbstractObjectUtils


  • public abstract class AbstractObjectUtils
    extends java.lang.Object
    Copy from https://github.com/spring-projects/spring-framework.git, with less modifications Miscellaneous object utility methods.

    Mainly for internal use within the framework.

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

    从以下版本开始:
    19.03.2004
    作者:
    Juergen Hoeller, Keith Donald, Rod Johnson, Rob Harrop, Chris Beams, Sam Brannen
    • 方法概要

      所有方法 静态方法 具体方法 已过时的方法 
      修饰符和类型 方法 说明
      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.
      private static boolean arrayEquals​(java.lang.Object o1, java.lang.Object o2)
      Compare the given arrays with Arrays.equals, performing an equality check based on the array elements rather than the array reference.
      static <E extends java.lang.Enum<?>>
      E
      caseInsensitiveValueOf​(E[] enumValues, java.lang.String constant)
      Case insensitive alternative to Enum.valueOf(Class, String).
      static boolean containsConstant​(java.lang.Enum<?>[] enumValues, java.lang.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​(java.lang.Enum<?>[] enumValues, java.lang.String constant, boolean caseSensitive)
      Check whether the given array of enum constants contains a constant with the given name.
      static boolean containsElement​(java.lang.Object[] array, java.lang.Object element)
      Check whether the given array contains the given element.
      static java.lang.String getDisplayString​(java.lang.Object obj)
      Return a content-based String representation if obj is not null; otherwise returns an empty String.
      static java.lang.String getIdentityHexString​(java.lang.Object obj)
      Return a hex String form of an object's identity hash code.
      static int hashCode​(boolean bool)
      已过时。
      as of Spring Framework 5.0, in favor of the native JDK 8 variant
      static int hashCode​(double dbl)
      已过时。
      as of Spring Framework 5.0, in favor of the native JDK 8 variant
      static int hashCode​(float flt)
      已过时。
      as of Spring Framework 5.0, in favor of the native JDK 8 variant
      static int hashCode​(long lng)
      已过时。
      as of Spring Framework 5.0, in favor of the native JDK 8 variant
      static java.lang.String identityToString​(java.lang.Object obj)
      Return a String representation of an object's overall identity.
      static boolean isArray​(java.lang.Object obj)
      Determine whether the given object is an array: either an Object array or a primitive array.
      static boolean isCheckedException​(java.lang.Throwable ex)
      Return whether the given throwable is a checked exception: that is, neither a RuntimeException nor an Error.
      static boolean isCompatibleWithThrowsClause​(java.lang.Throwable ex, java.lang.Class<?>... declaredExceptions)
      Check whether the given exception is compatible with the specified exception types, as declared in a throws clause.
      static boolean isEmpty​(java.lang.Object obj)
      Determine whether the given object is empty.
      static boolean isEmpty​(java.lang.Object[] array)
      Determine whether the given array is empty: i.e.
      static java.lang.String nullSafeClassName​(java.lang.Object obj)
      Determine the class name for the given object.
      static boolean nullSafeEquals​(java.lang.Object o1, java.lang.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​(java.lang.Object obj)
      Return as hash code for the given object; typically the value of Object#hashCode()}.
      static int nullSafeHashCode​(java.lang.Object[] array)
      Return a hash code based on the contents of the specified array.
      static java.lang.String nullSafeToString​(boolean[] array)
      Return a String representation of the contents of the specified array.
      static java.lang.String nullSafeToString​(byte[] array)
      Return a String representation of the contents of the specified array.
      static java.lang.String nullSafeToString​(char[] array)
      Return a String representation of the contents of the specified array.
      static java.lang.String nullSafeToString​(double[] array)
      Return a String representation of the contents of the specified array.
      static java.lang.String nullSafeToString​(float[] array)
      Return a String representation of the contents of the specified array.
      static java.lang.String nullSafeToString​(int[] array)
      Return a String representation of the contents of the specified array.
      static java.lang.String nullSafeToString​(long[] array)
      Return a String representation of the contents of the specified array.
      static java.lang.String nullSafeToString​(short[] array)
      Return a String representation of the contents of the specified array.
      static java.lang.String nullSafeToString​(java.lang.Object obj)
      Return a String representation of the specified Object.
      static java.lang.String nullSafeToString​(java.lang.Object[] array)
      Return a String representation of the contents of the specified array.
      static java.lang.Object[] toObjectArray​(java.lang.Object source)
      Convert the given array (which may be a primitive array) to an object array (if necessary of primitive wrapper objects).
      static java.lang.Object unwrapOptional​(java.lang.Object obj)
      Unwrap the given object which is potentially a Optional.
      • 从类继承的方法 java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • 字段详细资料

      • INITIAL_HASH

        private static final int INITIAL_HASH
        另请参阅:
        常量字段值
      • MULTIPLIER

        private static final int MULTIPLIER
        另请参阅:
        常量字段值
      • EMPTY_STRING

        private static final java.lang.String EMPTY_STRING
        另请参阅:
        常量字段值
      • NULL_STRING

        private static final java.lang.String NULL_STRING
        另请参阅:
        常量字段值
      • ARRAY_START

        private static final java.lang.String ARRAY_START
        另请参阅:
        常量字段值
      • ARRAY_END

        private static final java.lang.String ARRAY_END
        另请参阅:
        常量字段值
      • EMPTY_ARRAY

        private static final java.lang.String EMPTY_ARRAY
        另请参阅:
        常量字段值
      • ARRAY_ELEMENT_SEPARATOR

        private static final java.lang.String ARRAY_ELEMENT_SEPARATOR
        另请参阅:
        常量字段值
      • EMPTY_OBJECT_ARRAY

        private static final java.lang.Object[] EMPTY_OBJECT_ARRAY
    • 构造器详细资料

      • AbstractObjectUtils

        public AbstractObjectUtils()
    • 方法详细资料

      • isCheckedException

        public static boolean isCheckedException​(java.lang.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​(java.lang.Throwable ex,
                                                           java.lang.Class<?>... declaredExceptions)
        Check whether the given exception is compatible with the specified exception types, as declared in a throws clause.
        参数:
        ex - the exception to check
        declaredExceptions - the exception types declared in the throws clause
        返回:
        whether the given exception is compatible
      • isArray

        public static boolean isArray​(java.lang.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​(java.lang.Object[] array)
        Determine whether the given array is empty: i.e. null or of zero length.
        参数:
        array - the array to check
        另请参阅:
        isEmpty(Object)
      • isEmpty

        public static boolean isEmpty​(java.lang.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

        If the given object is non-null and not one of the aforementioned supported types, this method returns false.

        参数:
        obj - the object to check
        返回:
        true if the object is null or empty
        从以下版本开始:
        4.2
        另请参阅:
        Optional.isPresent(), isEmpty(Object[])
      • unwrapOptional

        public static java.lang.Object unwrapOptional​(java.lang.Object obj)
        Unwrap the given object which is potentially a Optional.
        参数:
        obj - the candidate object
        返回:
        either the value held within the Optional, null if the Optional is empty, or simply the given object as-is
        从以下版本开始:
        5.0
      • containsElement

        public static boolean containsElement​(java.lang.Object[] array,
                                              java.lang.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
      • containsConstant

        public static boolean containsConstant​(java.lang.Enum<?>[] enumValues,
                                               java.lang.String constant)
        Check whether the given array of enum constants contains a constant with the given name, ignoring case when determining a match.
        参数:
        enumValues - the enum values to check, typically obtained via MyEnum.values()
        constant - the constant name to find (must not be null or empty string)
        返回:
        whether the constant has been found in the given array
      • containsConstant

        public static boolean containsConstant​(java.lang.Enum<?>[] enumValues,
                                               java.lang.String constant,
                                               boolean caseSensitive)
        Check whether the given array of enum constants contains a constant with the given name.
        参数:
        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
        返回:
        whether the constant has been found in the given array
      • caseInsensitiveValueOf

        public static <E extends java.lang.Enum<?>> E caseInsensitiveValueOf​(E[] enumValues,
                                                                             java.lang.String constant)
        Case insensitive alternative to Enum.valueOf(Class, String).
        类型参数:
        E - the concrete Enum type
        参数:
        enumValues - the array of all Enum constants in question, usually per Enum.values()
        constant - the constant to get the enum value of
        抛出:
        java.lang.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[] 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.
        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 java.lang.Object[] toObjectArray​(java.lang.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:
        java.lang.IllegalArgumentException - if the parameter is not an array
      • nullSafeEquals

        public static boolean nullSafeEquals​(java.lang.Object o1,
                                             java.lang.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:
        Object.equals(Object), Arrays.equals(long[], long[])
      • arrayEquals

        private static boolean arrayEquals​(java.lang.Object o1,
                                           java.lang.Object o2)
        Compare the given arrays with Arrays.equals, performing an equality check based on the array elements rather than the array reference.
        参数:
        o1 - first array to compare
        o2 - second array to compare
        返回:
        whether the given objects are equal
        另请参阅:
        nullSafeEquals(Object, Object), Arrays.equals(long[], long[])
      • nullSafeHashCode

        public static int nullSafeHashCode​(java.lang.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

        @Deprecated
        public static int hashCode​(boolean bool)
        已过时。
        as of Spring Framework 5.0, in favor of the native JDK 8 variant
        Return the same value as Boolean.hashCode(boolean)}.
      • hashCode

        @Deprecated
        public static int hashCode​(double dbl)
        已过时。
        as of Spring Framework 5.0, in favor of the native JDK 8 variant
        Return the same value as Double.hashCode(double)}.
      • hashCode

        @Deprecated
        public static int hashCode​(float flt)
        已过时。
        as of Spring Framework 5.0, in favor of the native JDK 8 variant
        Return the same value as Float.hashCode(float)}.
      • hashCode

        @Deprecated
        public static int hashCode​(long lng)
        已过时。
        as of Spring Framework 5.0, in favor of the native JDK 8 variant
        Return the same value as Long.hashCode(long)}.
      • identityToString

        public static java.lang.String identityToString​(java.lang.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 java.lang.String getIdentityHexString​(java.lang.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 java.lang.String getDisplayString​(java.lang.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 java.lang.String nullSafeClassName​(java.lang.Object obj)
        Determine the class name for the given object.

        Returns a "null" String if obj is null.

        参数:
        obj - the object to introspect (may be null)
        返回:
        the corresponding class name
      • nullSafeToString

        public static java.lang.String nullSafeToString​(java.lang.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.

        参数:
        obj - the object to build a String representation for
        返回:
        a String representation of obj
      • nullSafeToString

        public static java.lang.String nullSafeToString​(java.lang.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 a "null" String 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 java.lang.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 a "null" String 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 java.lang.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 a "null" String 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 java.lang.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 a "null" String 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 java.lang.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 a "null" String 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 java.lang.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 a "null" String 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 java.lang.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 a "null" String 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 java.lang.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 a "null" String 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 java.lang.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 a "null" String if array is null.

        参数:
        array - the array to build a String representation for
        返回:
        a String representation of array