Class ObjectUtils
Object.
This class tries to handle null input gracefully.
An exception will generally not be thrown for a null input.
Each method documents its behavior in more detail.
#ThreadSafe#
- Since:
- 1.0
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionstatic classClass used as a null placeholder wherenullhas another meaning. -
Field Summary
FieldsModifier and TypeFieldDescriptionstatic final ObjectUtils.NullSingleton used as anullplaceholder wherenullhas another meaning. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionstatic booleanallNotNull(Object... values) Tests if all values in the array are notnulls.static booleanTests if all values in the given array arenull.static booleananyNotNull(Object... values) Tests if any value in the given array is notnull.static booleanTests if any value in the given array isnull.static <T> Tclone(T obj) Clones an object.static <T> TcloneIfPossible(T obj) Clones an object if possible.static <T extends Comparable<? super T>>
intcompare(T c1, T c2) Null safe comparison of Comparables.static <T extends Comparable<? super T>>
intcompare(T c1, T c2, boolean nullGreater) Null safe comparison of Comparables.static booleanCONST(boolean v) Returns the provided value unchanged.static byteCONST(byte v) Returns the provided value unchanged.static charCONST(char v) Returns the provided value unchanged.static doubleCONST(double v) Returns the provided value unchanged.static floatCONST(float v) Returns the provided value unchanged.static intCONST(int v) Returns the provided value unchanged.static longCONST(long v) Returns the provided value unchanged.static shortCONST(short v) Returns the provided value unchanged.static <T> TCONST(T v) Returns the provided value unchanged.static byteCONST_BYTE(int v) Returns the provided value unchanged.static shortCONST_SHORT(int v) Returns the provided value unchanged.static <T> TdefaultIfNull(T object, T defaultValue) Returns a default value if the object passed isnull.static booleanDeprecated.this method has been replaced byjava.util.Objects.equals(Object, Object)in Java 7 and will be removed from future releases.static <T> TfirstNonNull(T... values) Returns the first value in the array which is notnull.static <T> Class<T>getClass(T object) Delegates toObject.getClass()using generics.static <T> TgetFirstNonNull(Supplier<T>... suppliers) Executes the given suppliers in order and returns the first return value where a value other thannullis returned.static <T> TReturns the givenobjectis it is non-null, otherwise returns the Supplier'sSupplier.get()value.static intDeprecated.this method has been replaced byjava.util.Objects.hashCode(Object)in Java 7 and will be removed in future releasesstatic StringhashCodeHex(Object object) Returns the hexadecimal hash code for the given object perObjects.hashCode(Object).static inthashCodeMulti(Object... objects) Deprecated.this method has been replaced byjava.util.Objects.hash(Object...)in Java 7 and will be removed in future releases.static StringidentityHashCodeHex(Object object) Returns the hexadecimal hash code for the given object perSystem.identityHashCode(Object).static voididentityToString(Appendable appendable, Object object) Appends the toString that would be produced byObjectif a class did not override toString itself.static StringidentityToString(Object object) Gets the toString that would be produced byObjectif a class did not override toString itself.static voididentityToString(StringBuffer buffer, Object object) Appends the toString that would be produced byObjectif a class did not override toString itself.static voididentityToString(StringBuilder builder, Object object) Appends the toString that would be produced byObjectif a class did not override toString itself.static voididentityToString(StrBuilder builder, Object object) Deprecated.as of 3.6, because StrBuilder was moved to commons-text, use one of the otheridentityToStringmethods insteadstatic booleanTests whether the given object is an Object array or a primitive array in a null-safe manner.static booleanTests if an Object is empty or null.static booleanisNotEmpty(Object object) Tests if an Object is not empty and not null.static <T extends Comparable<? super T>>
Tmax(T... values) Null safe comparison of Comparables.static <T> Tmedian(Comparator<T> comparator, T... items) Find the "best guess" middle value among comparables.static <T extends Comparable<? super T>>
Tmedian(T... items) Find the "best guess" middle value among comparables.static <T extends Comparable<? super T>>
Tmin(T... values) Null safe comparison of Comparables.static <T> Tmode(T... items) Find the most frequently occurring item.static booleanCompares two objects for inequality, where either one or both objects may benull.static <T> TrequireNonEmpty(T obj) Checks that the specified object reference is notnullor empty perisEmpty(Object).static <T> TrequireNonEmpty(T obj, String message) Checks that the specified object reference is notnullor empty perisEmpty(Object).static StringDeprecated.this method has been replaced byjava.util.Objects.toString(Object)in Java 7 and will be removed in future releases.static StringDeprecated.this method has been replaced byjava.util.Objects.toString(Object, String)in Java 7 and will be removed in future releases.static Stringstatic <T> Stringstatic voidCallsObject.wait(long, int)for the given Duration.
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Field Details
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NULL
Singleton used as anullplaceholder wherenullhas another meaning.For example, in a
HashMaptheHashMap.get(Object)method returnsnullif theMapcontainsnullor if there is no matching key. Thenullplaceholder can be used to distinguish between these two cases.Another example is
Hashtable, wherenullcannot be stored.This instance is Serializable.
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Constructor Details
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ObjectUtils
Deprecated.TODO Make private in 4.0.ObjectUtilsinstances should NOT be constructed in standard programming. Instead, the static methods on the class should be used, such asObjectUtils.defaultIfNull("a","b");.This constructor is public to permit tools that require a JavaBean instance to operate.
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Method Details
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allNotNull
Tests if all values in the array are notnulls.If any value is
nullor the array isnullthenfalseis returned. If all elements in array are notnullor the array is empty (contains no elements)trueis returned.ObjectUtils.allNotNull(*) = true ObjectUtils.allNotNull(*, *) = true ObjectUtils.allNotNull(null) = false ObjectUtils.allNotNull(null, null) = false ObjectUtils.allNotNull(null, *) = false ObjectUtils.allNotNull(*, null) = false ObjectUtils.allNotNull(*, *, null, *) = false
- Parameters:
values- the values to test, may benullor empty- Returns:
falseif there is at least onenullvalue in the array or the array isnull,trueif all values in the array are notnulls or array contains no elements.- Since:
- 3.5
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allNull
Tests if all values in the given array arenull.If all the values are
nullor the array isnullor empty, thentrueis returned, otherwisefalseis returned.ObjectUtils.allNull(*) = false ObjectUtils.allNull(*, null) = false ObjectUtils.allNull(null, *) = false ObjectUtils.allNull(null, null, *, *) = false ObjectUtils.allNull(null) = true ObjectUtils.allNull(null, null) = true
- Parameters:
values- the values to test, may benullor empty- Returns:
trueif all values in the array arenulls,falseif there is at least one non-null value in the array.- Since:
- 3.11
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anyNotNull
Tests if any value in the given array is notnull.If all the values are
nullor the array isnullor empty thenfalseis returned. Otherwisetrueis returned.ObjectUtils.anyNotNull(*) = true ObjectUtils.anyNotNull(*, null) = true ObjectUtils.anyNotNull(null, *) = true ObjectUtils.anyNotNull(null, null, *, *) = true ObjectUtils.anyNotNull(null) = false ObjectUtils.anyNotNull(null, null) = false
- Parameters:
values- the values to test, may benullor empty- Returns:
trueif there is at least one non-null value in the array,falseif all values in the array arenulls. If the array isnullor emptyfalseis also returned.- Since:
- 3.5
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anyNull
Tests if any value in the given array isnull.If any of the values are
nullor the array isnull, thentrueis returned, otherwisefalseis returned.ObjectUtils.anyNull(*) = false ObjectUtils.anyNull(*, *) = false ObjectUtils.anyNull(null) = true ObjectUtils.anyNull(null, null) = true ObjectUtils.anyNull(null, *) = true ObjectUtils.anyNull(*, null) = true ObjectUtils.anyNull(*, *, null, *) = true
- Parameters:
values- the values to test, may benullor empty- Returns:
trueif there is at least onenullvalue in the array,falseif all the values are non-null. If the array isnullor empty,trueis also returned.- Since:
- 3.11
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clone
Clones an object.- Type Parameters:
T- the type of the object- Parameters:
obj- the object to clone, null returns null- Returns:
- the clone if the object implements
Cloneableotherwisenull - Throws:
CloneFailedException- if the object is cloneable and the clone operation fails- Since:
- 3.0
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cloneIfPossible
Clones an object if possible.This method is similar to
clone(Object), but will return the provided instance as the return value instead ofnullif the instance is not cloneable. This is more convenient if the caller uses different implementations (e.g. of a service) and some of the implementations do not allow concurrent processing or have state. In such cases the implementation can simply provide a proper clone implementation and the caller's code does not have to change.- Type Parameters:
T- the type of the object- Parameters:
obj- the object to clone, null returns null- Returns:
- the clone if the object implements
Cloneableotherwise the object itself - Throws:
CloneFailedException- if the object is cloneable and the clone operation fails- Since:
- 3.0
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compare
Null safe comparison of Comparables.nullis assumed to be less than a non-nullvalue.TODO Move to ComparableUtils.
- Type Parameters:
T- type of the values processed by this method- Parameters:
c1- the first comparable, may be nullc2- the second comparable, may be null- Returns:
- a negative value if c1 < c2, zero if c1 = c2 and a positive value if c1 > c2
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compare
Null safe comparison of Comparables.TODO Move to ComparableUtils.
- Type Parameters:
T- type of the values processed by this method- Parameters:
c1- the first comparable, may be nullc2- the second comparable, may be nullnullGreater- if truenullis considered greater than a non-nullvalue or if falsenullis considered less than a Non-nullvalue- Returns:
- a negative value if c1 < c2, zero if c1 = c2 and a positive value if c1 > c2
- See Also:
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CONST
Returns the provided value unchanged. This can prevent javac from inlining a constant field, e.g.,public final static boolean MAGIC_FLAG = ObjectUtils.CONST(true);This way any jars that refer to this field do not have to recompile themselves if the field's value changes at some future date.- Parameters:
v- the boolean value to return- Returns:
- the boolean v, unchanged
- Since:
- 3.2
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CONST
Returns the provided value unchanged. This can prevent javac from inlining a constant field, e.g.,public final static byte MAGIC_BYTE = ObjectUtils.CONST((byte) 127);This way any jars that refer to this field do not have to recompile themselves if the field's value changes at some future date.- Parameters:
v- the byte value to return- Returns:
- the byte v, unchanged
- Since:
- 3.2
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CONST
Returns the provided value unchanged. This can prevent javac from inlining a constant field, e.g.,public final static char MAGIC_CHAR = ObjectUtils.CONST('a');This way any jars that refer to this field do not have to recompile themselves if the field's value changes at some future date.- Parameters:
v- the char value to return- Returns:
- the char v, unchanged
- Since:
- 3.2
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CONST
Returns the provided value unchanged. This can prevent javac from inlining a constant field, e.g.,public final static double MAGIC_DOUBLE = ObjectUtils.CONST(1.0);This way any jars that refer to this field do not have to recompile themselves if the field's value changes at some future date.- Parameters:
v- the double value to return- Returns:
- the double v, unchanged
- Since:
- 3.2
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CONST
Returns the provided value unchanged. This can prevent javac from inlining a constant field, e.g.,public final static float MAGIC_FLOAT = ObjectUtils.CONST(1.0f);This way any jars that refer to this field do not have to recompile themselves if the field's value changes at some future date.- Parameters:
v- the float value to return- Returns:
- the float v, unchanged
- Since:
- 3.2
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CONST
Returns the provided value unchanged. This can prevent javac from inlining a constant field, e.g.,public final static int MAGIC_INT = ObjectUtils.CONST(123);This way any jars that refer to this field do not have to recompile themselves if the field's value changes at some future date.- Parameters:
v- the int value to return- Returns:
- the int v, unchanged
- Since:
- 3.2
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CONST
Returns the provided value unchanged. This can prevent javac from inlining a constant field, e.g.,public final static long MAGIC_LONG = ObjectUtils.CONST(123L);This way any jars that refer to this field do not have to recompile themselves if the field's value changes at some future date.- Parameters:
v- the long value to return- Returns:
- the long v, unchanged
- Since:
- 3.2
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CONST
Returns the provided value unchanged. This can prevent javac from inlining a constant field, e.g.,public final static short MAGIC_SHORT = ObjectUtils.CONST((short) 123);This way any jars that refer to this field do not have to recompile themselves if the field's value changes at some future date.- Parameters:
v- the short value to return- Returns:
- the short v, unchanged
- Since:
- 3.2
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CONST
Returns the provided value unchanged. This can prevent javac from inlining a constant field, e.g.,public final static String MAGIC_STRING = ObjectUtils.CONST("abc");This way any jars that refer to this field do not have to recompile themselves if the field's value changes at some future date.- Type Parameters:
T- the Object type- Parameters:
v- the genericized Object value to return (typically a String).- Returns:
- the genericized Object v, unchanged (typically a String).
- Since:
- 3.2
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CONST_BYTE
Returns the provided value unchanged. This can prevent javac from inlining a constant field, e.g.,public final static byte MAGIC_BYTE = ObjectUtils.CONST_BYTE(127);This way any jars that refer to this field do not have to recompile themselves if the field's value changes at some future date.- Parameters:
v- the byte literal (as an int) value to return- Returns:
- the byte v, unchanged
- Throws:
IllegalArgumentException- if the value passed to v is larger than a byte, that is, smaller than -128 or larger than 127.- Since:
- 3.2
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CONST_SHORT
Returns the provided value unchanged. This can prevent javac from inlining a constant field, e.g.,public final static short MAGIC_SHORT = ObjectUtils.CONST_SHORT(127);This way any jars that refer to this field do not have to recompile themselves if the field's value changes at some future date.- Parameters:
v- the short literal (as an int) value to return- Returns:
- the byte v, unchanged
- Throws:
IllegalArgumentException- if the value passed to v is larger than a short, that is, smaller than -32768 or larger than 32767.- Since:
- 3.2
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defaultIfNull
Returns a default value if the object passed isnull.ObjectUtils.defaultIfNull(null, null) = null ObjectUtils.defaultIfNull(null, "") = "" ObjectUtils.defaultIfNull(null, "zz") = "zz" ObjectUtils.defaultIfNull("abc", *) = "abc" ObjectUtils.defaultIfNull(Boolean.TRUE, *) = Boolean.TRUE- Type Parameters:
T- the type of the object- Parameters:
object- theObjectto test, may benulldefaultValue- the default value to return, may benull- Returns:
objectif it is notnull, defaultValue otherwise TODO Rename to getIfNull in 4.0
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equals
Deprecated.this method has been replaced byjava.util.Objects.equals(Object, Object)in Java 7 and will be removed from future releases.Compares two objects for equality, where either one or both objects may benull.ObjectUtils.equals(null, null) = true ObjectUtils.equals(null, "") = false ObjectUtils.equals("", null) = false ObjectUtils.equals("", "") = true ObjectUtils.equals(Boolean.TRUE, null) = false ObjectUtils.equals(Boolean.TRUE, "true") = false ObjectUtils.equals(Boolean.TRUE, Boolean.TRUE) = true ObjectUtils.equals(Boolean.TRUE, Boolean.FALSE) = false- Parameters:
object1- the first object, may benullobject2- the second object, may benull- Returns:
trueif the values of both objects are the same
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firstNonNull
Returns the first value in the array which is notnull. If all the values arenullor the array isnullor empty thennullis returned.ObjectUtils.firstNonNull(null, null) = null ObjectUtils.firstNonNull(null, "") = "" ObjectUtils.firstNonNull(null, null, "") = "" ObjectUtils.firstNonNull(null, "zz") = "zz" ObjectUtils.firstNonNull("abc", *) = "abc" ObjectUtils.firstNonNull(null, "xyz", *) = "xyz" ObjectUtils.firstNonNull(Boolean.TRUE, *) = Boolean.TRUE ObjectUtils.firstNonNull() = null- Type Parameters:
T- the component type of the array- Parameters:
values- the values to test, may benullor empty- Returns:
- the first value from
valueswhich is notnull, ornullif there are no non-null values - Since:
- 3.0
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getClass
Delegates toObject.getClass()using generics.- Type Parameters:
T- The argument type or null.- Parameters:
object- The argument.- Returns:
- The argument's Class or null.
- Since:
- 3.13.0
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getFirstNonNull
Executes the given suppliers in order and returns the first return value where a value other thannullis returned. Once a non-nullvalue is obtained, all following suppliers are not executed anymore. If all the return values arenullor no suppliers are provided thennullis returned.ObjectUtils.firstNonNullLazy(null, () -> null) = null ObjectUtils.firstNonNullLazy(() -> null, () -> "") = "" ObjectUtils.firstNonNullLazy(() -> "", () -> throw new IllegalStateException()) = "" ObjectUtils.firstNonNullLazy(() -> null, () -> "zz) = "zz" ObjectUtils.firstNonNullLazy() = null
- Type Parameters:
T- the type of the return values- Parameters:
suppliers- the suppliers returning the values to test.nullvalues are ignored. Suppliers may returnnullor a value of typeT- Returns:
- the first return value from
supplierswhich is notnull, ornullif there are no non-null values - Since:
- 3.10
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getIfNull
Returns the givenobjectis it is non-null, otherwise returns the Supplier'sSupplier.get()value.The caller responsible for thread-safety and exception handling of default value supplier.
ObjectUtils.getIfNull(null, () -> null) = null ObjectUtils.getIfNull(null, null) = null ObjectUtils.getIfNull(null, () -> "") = "" ObjectUtils.getIfNull(null, () -> "zz") = "zz" ObjectUtils.getIfNull("abc", *) = "abc" ObjectUtils.getIfNull(Boolean.TRUE, *) = Boolean.TRUE- Type Parameters:
T- the type of the object- Parameters:
object- theObjectto test, may benulldefaultSupplier- the default value to return, may benull- Returns:
objectif it is notnull,defaultValueSupplier.get()otherwise- Since:
- 3.10
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hashCode
Deprecated.this method has been replaced byjava.util.Objects.hashCode(Object)in Java 7 and will be removed in future releasesGets the hash code of an object returning zero when the object isnull.ObjectUtils.hashCode(null) = 0 ObjectUtils.hashCode(obj) = obj.hashCode()
- Parameters:
obj- the object to obtain the hash code of, may benull- Returns:
- the hash code of the object, or zero if null
- Since:
- 2.1
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hashCodeHex
Returns the hexadecimal hash code for the given object perObjects.hashCode(Object).Short hand for
Integer.toHexString(Objects.hashCode(object)).- Parameters:
object- object for which the hashCode is to be calculated- Returns:
- Hash code in hexadecimal format.
- Since:
- 3.13.0
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hashCodeMulti
Deprecated.this method has been replaced byjava.util.Objects.hash(Object...)in Java 7 and will be removed in future releases.Gets the hash code for multiple objects.This allows a hash code to be rapidly calculated for a number of objects. The hash code for a single object is the not same as
hashCode(Object). The hash code for multiple objects is the same as that calculated by anArrayListcontaining the specified objects.ObjectUtils.hashCodeMulti() = 1 ObjectUtils.hashCodeMulti((Object[]) null) = 1 ObjectUtils.hashCodeMulti(a) = 31 + a.hashCode() ObjectUtils.hashCodeMulti(a,b) = (31 + a.hashCode()) * 31 + b.hashCode() ObjectUtils.hashCodeMulti(a,b,c) = ((31 + a.hashCode()) * 31 + b.hashCode()) * 31 + c.hashCode()
- Parameters:
objects- the objects to obtain the hash code of, may benull- Returns:
- the hash code of the objects, or zero if null
- Since:
- 3.0
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identityHashCodeHex
Returns the hexadecimal hash code for the given object perSystem.identityHashCode(Object).Short hand for
Integer.toHexString(System.identityHashCode(object)).- Parameters:
object- object for which the hashCode is to be calculated- Returns:
- Hash code in hexadecimal format.
- Since:
- 3.13.0
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identityToString
Appends the toString that would be produced byObjectif a class did not override toString itself.nullwill throw a NullPointerException for either of the two parameters.ObjectUtils.identityToString(appendable, "") = appendable.append("java.lang.String@1e23") ObjectUtils.identityToString(appendable, Boolean.TRUE) = appendable.append("java.lang.Boolean@7fa") ObjectUtils.identityToString(appendable, Boolean.TRUE) = appendable.append("java.lang.Boolean@7fa")- Parameters:
appendable- the appendable to append toobject- the object to create a toString for- Throws:
IOException- if an I/O error occurs.- Since:
- 3.2
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identityToString
Gets the toString that would be produced byObjectif a class did not override toString itself.nullwill returnnull.ObjectUtils.identityToString(null) = null ObjectUtils.identityToString("") = "java.lang.String@1e23" ObjectUtils.identityToString(Boolean.TRUE) = "java.lang.Boolean@7fa"- Parameters:
object- the object to create a toString for, may benull- Returns:
- the default toString text, or
nullifnullpassed in
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identityToString
Deprecated.as of 3.6, because StrBuilder was moved to commons-text, use one of the otheridentityToStringmethods insteadAppends the toString that would be produced byObjectif a class did not override toString itself.nullwill throw a NullPointerException for either of the two parameters.ObjectUtils.identityToString(builder, "") = builder.append("java.lang.String@1e23") ObjectUtils.identityToString(builder, Boolean.TRUE) = builder.append("java.lang.Boolean@7fa") ObjectUtils.identityToString(builder, Boolean.TRUE) = builder.append("java.lang.Boolean@7fa")- Parameters:
builder- the builder to append toobject- the object to create a toString for- Since:
- 3.2
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identityToString
Appends the toString that would be produced byObjectif a class did not override toString itself.nullwill throw a NullPointerException for either of the two parameters.ObjectUtils.identityToString(buf, "") = buf.append("java.lang.String@1e23") ObjectUtils.identityToString(buf, Boolean.TRUE) = buf.append("java.lang.Boolean@7fa") ObjectUtils.identityToString(buf, Boolean.TRUE) = buf.append("java.lang.Boolean@7fa")- Parameters:
buffer- the buffer to append toobject- the object to create a toString for- Since:
- 2.4
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identityToString
Appends the toString that would be produced byObjectif a class did not override toString itself.nullwill throw a NullPointerException for either of the two parameters.ObjectUtils.identityToString(builder, "") = builder.append("java.lang.String@1e23") ObjectUtils.identityToString(builder, Boolean.TRUE) = builder.append("java.lang.Boolean@7fa") ObjectUtils.identityToString(builder, Boolean.TRUE) = builder.append("java.lang.Boolean@7fa")- Parameters:
builder- the builder to append toobject- the object to create a toString for- Since:
- 3.2
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isArray
Tests whether the given object is an Object array or a primitive array in a null-safe manner.A
nullobjectObject will returnfalse.ObjectUtils.isArray(null) = false ObjectUtils.isArray("") = false ObjectUtils.isArray("ab") = false ObjectUtils.isArray(new int[]{}) = true ObjectUtils.isArray(new int[]{1,2,3}) = true ObjectUtils.isArray(1234) = false- Parameters:
object- the object to check, may benull- Returns:
trueif the object is anarray,falseotherwise- Since:
- 3.13.0
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isEmpty
Tests if an Object is empty or null. The following types are supported:CharSequence: Considered empty if its length is zero.Array: Considered empty if its length is zero.Collection: Considered empty if it has zero elements.Map: Considered empty if it has zero key-value mappings.Optional: Considered empty ifOptional.isPresent()returns false, regardless of the "emptiness" of the contents.
ObjectUtils.isEmpty(null) = true ObjectUtils.isEmpty("") = true ObjectUtils.isEmpty("ab") = false ObjectUtils.isEmpty(new int[]{}) = true ObjectUtils.isEmpty(new int[]{1,2,3}) = false ObjectUtils.isEmpty(1234) = false ObjectUtils.isEmpty(1234) = false ObjectUtils.isEmpty(Optional.of("")) = false ObjectUtils.isEmpty(Optional.empty()) = true- Parameters:
object- theObjectto test, may benull- Returns:
trueif the object has a supported type and is empty or null,falseotherwise- Since:
- 3.9
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isNotEmpty
Tests if an Object is not empty and not null. The following types are supported:CharSequence: Considered empty if its length is zero.Array: Considered empty if its length is zero.Collection: Considered empty if it has zero elements.Map: Considered empty if it has zero key-value mappings.Optional: Considered empty ifOptional.isPresent()returns false, regardless of the "emptiness" of the contents.
ObjectUtils.isNotEmpty(null) = false ObjectUtils.isNotEmpty("") = false ObjectUtils.isNotEmpty("ab") = true ObjectUtils.isNotEmpty(new int[]{}) = false ObjectUtils.isNotEmpty(new int[]{1,2,3}) = true ObjectUtils.isNotEmpty(1234) = true ObjectUtils.isNotEmpty(Optional.of("")) = true ObjectUtils.isNotEmpty(Optional.empty()) = false- Parameters:
object- theObjectto test, may benull- Returns:
trueif the object has an unsupported type or is not empty and not null,falseotherwise- Since:
- 3.9
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max
Null safe comparison of Comparables.TODO Move to ComparableUtils.
- Type Parameters:
T- type of the values processed by this method- Parameters:
values- the set of comparable values, may be null- Returns:
- If any objects are non-null and unequal, the greater object.
- If all objects are non-null and equal, the first.
- If any of the comparables are null, the greater of the non-null objects.
- If all the comparables are null, null is returned.
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median
Find the "best guess" middle value among comparables. If there is an even number of total values, the lower of the two middle values will be returned.- Type Parameters:
T- type of values processed by this method- Parameters:
comparator- to use for comparisonsitems- to compare- Returns:
- T at middle position
- Throws:
NullPointerException- if items or comparator isnullIllegalArgumentException- if items is empty or containsnullvalues- Since:
- 3.0.1
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median
Find the "best guess" middle value among comparables. If there is an even number of total values, the lower of the two middle values will be returned.- Type Parameters:
T- type of values processed by this method- Parameters:
items- to compare- Returns:
- T at middle position
- Throws:
NullPointerException- if items isnullIllegalArgumentException- if items is empty or containsnullvalues- Since:
- 3.0.1
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min
Null safe comparison of Comparables.TODO Move to ComparableUtils.
- Type Parameters:
T- type of the values processed by this method- Parameters:
values- the set of comparable values, may be null- Returns:
- If any objects are non-null and unequal, the lesser object.
- If all objects are non-null and equal, the first.
- If any of the comparables are null, the lesser of the non-null objects.
- If all the comparables are null, null is returned.
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mode
Find the most frequently occurring item.- Type Parameters:
T- type of values processed by this method- Parameters:
items- to check- Returns:
- most populous T,
nullif non-unique or no items supplied - Since:
- 3.0.1
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notEqual
Compares two objects for inequality, where either one or both objects may benull.ObjectUtils.notEqual(null, null) = false ObjectUtils.notEqual(null, "") = true ObjectUtils.notEqual("", null) = true ObjectUtils.notEqual("", "") = false ObjectUtils.notEqual(Boolean.TRUE, null) = true ObjectUtils.notEqual(Boolean.TRUE, "true") = true ObjectUtils.notEqual(Boolean.TRUE, Boolean.TRUE) = false ObjectUtils.notEqual(Boolean.TRUE, Boolean.FALSE) = true- Parameters:
object1- the first object, may benullobject2- the second object, may benull- Returns:
falseif the values of both objects are the same
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requireNonEmpty
Checks that the specified object reference is notnullor empty perisEmpty(Object). Use this method for validation, for example:public Foo(Bar bar) { this.bar = Objects.requireNonEmpty(bar); }- Type Parameters:
T- the type of the reference.- Parameters:
obj- the object reference to check for nullity.- Returns:
objif notnull.- Throws:
NullPointerException- ifobjisnull.IllegalArgumentException- ifobjis empty perisEmpty(Object).- Since:
- 3.12.0
- See Also:
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requireNonEmpty
Checks that the specified object reference is notnullor empty perisEmpty(Object). Use this method for validation, for example:public Foo(Bar bar) { this.bar = Objects.requireNonEmpty(bar, "bar"); }- Type Parameters:
T- the type of the reference.- Parameters:
obj- the object reference to check for nullity.message- the exception message.- Returns:
objif notnull.- Throws:
NullPointerException- ifobjisnull.IllegalArgumentException- ifobjis empty perisEmpty(Object).- Since:
- 3.12.0
- See Also:
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toString
Deprecated.this method has been replaced byjava.util.Objects.toString(Object)in Java 7 and will be removed in future releases. Note however that said method will return "null" for null references, while this method returns an empty String. To preserve behavior usejava.util.Objects.toString(myObject, "")Gets thetoStringof anObjectreturning an empty string ("") ifnullinput.ObjectUtils.toString(null) = "" ObjectUtils.toString("") = "" ObjectUtils.toString("bat") = "bat" ObjectUtils.toString(Boolean.TRUE) = "true"- Parameters:
obj- the Object totoString, may be null- Returns:
- the passed in Object's toString, or
""ifnullinput - Since:
- 2.0
- See Also:
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toString
Deprecated.this method has been replaced byjava.util.Objects.toString(Object, String)in Java 7 and will be removed in future releases.Gets thetoStringof anObjectreturning a specified text ifnullinput.ObjectUtils.toString(null, null) = null ObjectUtils.toString(null, "null") = "null" ObjectUtils.toString("", "null") = "" ObjectUtils.toString("bat", "null") = "bat" ObjectUtils.toString(Boolean.TRUE, "null") = "true"- Parameters:
obj- the Object totoString, may be nullnullStr- the String to return ifnullinput, may be null- Returns:
- the passed in Object's toString, or
nullStrifnullinput - Since:
- 2.0
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toString
Gets thetoStringof anSupplier'sSupplier.get()returning a specified text ifnullinput.ObjectUtils.toString(() -> obj, () -> expensive())
ObjectUtils.toString(() -> null, () -> expensive()) = result of expensive() ObjectUtils.toString(() -> null, () -> expensive()) = result of expensive() ObjectUtils.toString(() -> "", () -> expensive()) = "" ObjectUtils.toString(() -> "bat", () -> expensive()) = "bat" ObjectUtils.toString(() -> Boolean.TRUE, () -> expensive()) = "true"
- Parameters:
obj- the Object totoString, may be nullsupplier- the Supplier of String used onnullinput, may be null- Returns:
- the passed in Object's toString, or
nullStrifnullinput - Since:
- 3.14.0
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toString
Gets thetoStringof anObjectreturning a specified text ifnullinput.ObjectUtils.toString(obj, () -> expensive())
ObjectUtils.toString(null, () -> expensive()) = result of expensive() ObjectUtils.toString(null, () -> expensive()) = result of expensive() ObjectUtils.toString("", () -> expensive()) = "" ObjectUtils.toString("bat", () -> expensive()) = "bat" ObjectUtils.toString(Boolean.TRUE, () -> expensive()) = "true"- Type Parameters:
T- the obj type (used to provide better source compatibility in 3.14.0).- Parameters:
obj- the Object totoString, may be nullsupplier- the Supplier of String used onnullinput, may be null- Returns:
- the passed in Object's toString, or
nullStrifnullinput - Since:
- 3.11
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wait
CallsObject.wait(long, int)for the given Duration.- Parameters:
obj- The receiver of the wait call.duration- How long to wait.- Throws:
IllegalArgumentException- if the timeout duration is negative.IllegalMonitorStateException- if the current thread is not the owner of theobj's monitor.InterruptedException- if any thread interrupted the current thread before or while the current thread was waiting for a notification. The interrupted status of the current thread is cleared when this exception is thrown.- Since:
- 3.12.0
- See Also:
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