- java.lang.Object
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- org.apache.lucene.util.AttributeFactory
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- Direct Known Subclasses:
AttributeFactory.DefaultAttributeFactory
,AttributeFactory.StaticImplementationAttributeFactory
public abstract class AttributeFactory extends java.lang.Object
An AttributeFactory creates instances ofAttributeImpl
s.
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Nested Class Summary
Nested Classes Modifier and Type Class Description private static class
AttributeFactory.DefaultAttributeFactory
static class
AttributeFactory.StaticImplementationAttributeFactory<A extends AttributeImpl>
Expert: AttributeFactory returning an instance of the givenclazz
for the attributes it implements.
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Field Summary
Fields Modifier and Type Field Description static AttributeFactory
DEFAULT_ATTRIBUTE_FACTORY
This is the default factory that createsAttributeImpl
s using the class name of the suppliedAttribute
interface class by appendingImpl
to it.private static java.lang.invoke.MethodHandles.Lookup
lookup
private static java.lang.invoke.MethodType
NO_ARG_CTOR
private static java.lang.invoke.MethodType
NO_ARG_RETURNING_ATTRIBUTEIMPL
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Constructor Summary
Constructors Constructor Description AttributeFactory()
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Method Summary
All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description abstract AttributeImpl
createAttributeInstance(java.lang.Class<? extends Attribute> attClass)
Returns anAttributeImpl
for the suppliedAttribute
interface class.(package private) static java.lang.invoke.MethodHandle
findAttributeImplCtor(java.lang.Class<? extends AttributeImpl> clazz)
Returns a correctly typedMethodHandle
for the no-arg ctor of the given class.static <A extends AttributeImpl>
AttributeFactorygetStaticImplementation(AttributeFactory delegate, java.lang.Class<A> clazz)
Returns an AttributeFactory returning an instance of the givenclazz
for the attributes it implements.
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Field Detail
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lookup
private static final java.lang.invoke.MethodHandles.Lookup lookup
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NO_ARG_CTOR
private static final java.lang.invoke.MethodType NO_ARG_CTOR
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NO_ARG_RETURNING_ATTRIBUTEIMPL
private static final java.lang.invoke.MethodType NO_ARG_RETURNING_ATTRIBUTEIMPL
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DEFAULT_ATTRIBUTE_FACTORY
public static final AttributeFactory DEFAULT_ATTRIBUTE_FACTORY
This is the default factory that createsAttributeImpl
s using the class name of the suppliedAttribute
interface class by appendingImpl
to it.
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Method Detail
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createAttributeInstance
public abstract AttributeImpl createAttributeInstance(java.lang.Class<? extends Attribute> attClass) throws java.lang.reflect.UndeclaredThrowableException
Returns anAttributeImpl
for the suppliedAttribute
interface class.- Throws:
java.lang.reflect.UndeclaredThrowableException
- A wrapper runtime exception thrown if the constructor of the attribute class throws a checked exception. Note that attributes should not throw or declare checked exceptions; this may be verified and fail early in the future.
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findAttributeImplCtor
static final java.lang.invoke.MethodHandle findAttributeImplCtor(java.lang.Class<? extends AttributeImpl> clazz)
Returns a correctly typedMethodHandle
for the no-arg ctor of the given class.
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getStaticImplementation
public static <A extends AttributeImpl> AttributeFactory getStaticImplementation(AttributeFactory delegate, java.lang.Class<A> clazz)
Returns an AttributeFactory returning an instance of the givenclazz
for the attributes it implements. The givenclazz
must have a public no-arg constructor. For all other attributes it calls the given delegate factory as fallback. This method can be used to prefer a specificAttributeImpl
which combines multiple attributes over separate classes.Please save instances created by this method in a static final field, because on each call, this does reflection for creating a
MethodHandle
.
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