Package org.apache.lucene.util
Class SetOnce<T>
java.lang.Object
org.apache.lucene.util.SetOnce<T>
- All Implemented Interfaces:
Cloneable
A convenient class which offers a semi-immutable object wrapper
implementation which allows one to set the value of an object exactly once,
and retrieve it many times. If
set(Object)
is called more than once,
SetOnce.AlreadySetException
is thrown and the operation
will fail.-
Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionstatic final class
Thrown whenset(Object)
is called more than once. -
Constructor Summary
ConstructorsConstructorDescriptionSetOnce()
A default constructor which does not set the internal object, and allows setting it by callingset(Object)
.Creates a new instance with the internal object set to the given object. -
Method Summary
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Constructor Details
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SetOnce
public SetOnce()A default constructor which does not set the internal object, and allows setting it by callingset(Object)
. -
SetOnce
Creates a new instance with the internal object set to the given object. Note that any calls toset(Object)
afterwards will result inSetOnce.AlreadySetException
- Throws:
SetOnce.AlreadySetException
- if called more than once- See Also:
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Method Details
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set
Sets the given object. If the object has already been set, an exception is thrown. -
get
Returns the object set byset(Object)
. -
clone
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