Class GosuObjectUtil
This class is directly derived from org.apache.commons.lang.ObjectUtils and is intended to avoid dependencies on that project.
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionstatic class
Class used as a null placeholder wherenull
has another meaning. -
Field Summary
FieldsModifier and TypeFieldDescriptionstatic final GosuObjectUtil.Null
Singleton used as anull
placeholder wherenull
has another meaning. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionstatic StringBuffer
appendIdentityToString
(StringBuffer buffer, Object object) Deprecated.The design of this method is bad - see LANG-360.static int
arrayHashCode
(Object array) Return the hash code for an arraystatic Object
defaultIfNull
(Object object, Object defaultValue) Returns a default value if the object passed isnull
.static boolean
Compares two objects for equality, where either one or both objects may benull
.static int
Gets the hash code of an object returning zero when the object isnull
.static String
identityToString
(Object object) Gets the toString that would be produced byObject
if a class did not override toString itself.static void
identityToString
(StringBuffer buffer, Object object) Appends the toString that would be produced byObject
if a class did not override toString itself.static boolean
static Object
max
(Comparable c1, Comparable c2) Null safe comparison of Comparables.static Object
min
(Comparable c1, Comparable c2) Null safe comparison of Comparables.static String
Gets thetoString
of anObject
returning an empty string ("") ifnull
input.static String
Gets thetoString
of anObject
returning a specified text ifnull
input.
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Field Details
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NULL
Singleton used as a
null
placeholder wherenull
has another meaning.For example, in a
HashMap
theHashMap.get(java.lang.Object)
method returnsnull
if theMap
containsnull
or if there is no matching key. TheNull
placeholder can be used to distinguish between these two cases.Another example is
Hashtable
, wherenull
cannot be stored.This instance is Serializable.
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Constructor Details
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GosuObjectUtil
public GosuObjectUtil()
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Method Details
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defaultIfNull
Returns a default value if the object passed is
null
.ObjectUtils.defaultIfNull(null, null) = null ObjectUtils.defaultIfNull(null, "") = "" ObjectUtils.defaultIfNull(null, "zz") = "zz" ObjectUtils.defaultIfNull("abc", *) = "abc" ObjectUtils.defaultIfNull(Boolean.TRUE, *) = Boolean.TRUE
- Parameters:
object
- theObject
to test, may benull
defaultValue
- the default value to return, may benull
- Returns:
object
if it is notnull
, defaultValue otherwise
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equals
Compares two objects for equality, where either one or both objects may be
null
.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 benull
object2
- the second object, may benull
- Returns:
true
if the values of both objects are the same
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hashCode
Gets the hash code of an object returning zero when the object is
null
.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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identityToString
Gets the toString that would be produced by
Object
if a class did not override toString itself.null
will 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
null
ifnull
passed in
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isJavaReferenceArray
- Returns:
- true if the given object is a pure java object array, false otherwise
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identityToString
Appends the toString that would be produced by
Object
if a class did not override toString itself.null
will 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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appendIdentityToString
Deprecated.The design of this method is bad - see LANG-360. Instead, use identityToString(StringBuffer, Object).Appends the toString that would be produced by
Object
if a class did not override toString itself.null
will returnnull
.ObjectUtils.appendIdentityToString(*, null) = null ObjectUtils.appendIdentityToString(null, "") = "java.lang.String@1e23" ObjectUtils.appendIdentityToString(null, Boolean.TRUE) = "java.lang.Boolean@7fa" ObjectUtils.appendIdentityToString(buf, Boolean.TRUE) = buf.append("java.lang.Boolean@7fa")
- Parameters:
buffer
- the buffer to append to, may benull
object
- the object to create a toString for, may benull
- Returns:
- the default toString text, or
null
ifnull
passed in - Since:
- 2.0
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toString
Gets the
toString
of anObject
returning an empty string ("") ifnull
input.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 nullStr if
null
input - Since:
- 2.0
- See Also:
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toString
Gets the
toString
of anObject
returning a specified text ifnull
input.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 ifnull
input, may be null- Returns:
- the passed in Object's toString, or nullStr if
null
input - Since:
- 2.0
- See Also:
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min
Null safe comparison of Comparables.- Parameters:
c1
- the first comparable, may be nullc2
- the second comparable, may be null- Returns:
- If both objects are non-null and unequal, the lesser object.
- If both objects are non-null and equal, c1.
- If one of the comparables is null, the non-null object.
- If both the comparables are null, null is returned.
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max
Null safe comparison of Comparables.- Parameters:
c1
- the first comparable, may be nullc2
- the second comparable, may be null- Returns:
- If both objects are non-null and unequal, the greater object.
- If both objects are non-null and equal, c1.
- If one of the comparables is null, the non-null object.
- If both the comparables are null, null is returned.
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arrayHashCode
Return the hash code for an array- Parameters:
array
- the array to compute the hash code.
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