OpenJDK 27 · sun.reflect.ReflectionFactory · APIdia, the JavaDoc alternative

Modifier and Type	Field and Description
private static final ReflectionFactory	delegate
private static final ReflectionFactory	soleInstance

Access	Constructor and Description
private	ReflectionFactory()

Method Summary

Modifier and Type	Method and Description
public final MethodHandle	Returns: a direct MethodHandle for the synthetic `readObject` method or `null` if the class falls in a disallowed category defaultReadObjectForSerialization(Class<?> a Serializable class cl) Generate and return a direct MethodHandle which implements the general default behavior for serializable class's `readObject`.
public final MethodHandle	Returns: a direct MethodHandle for the synthetic `writeObject` method or `null` if the class falls in a disallowed category defaultWriteObjectForSerialization(Class<?> a Serializable class cl) Generate and return a direct MethodHandle which implements the general default behavior for serializable class's `writeObject`.
public static ReflectionFactory	Returns: the ReflectionFactory getReflectionFactory() Provides the caller with the capability to instantiate reflective objects.
public final boolean	Returns: `true` if the class has a static initializer, otherwise `false` hasStaticInitializerForSerialization(Class<?> a serializable class cl) Returns true if the class has a static initializer.
public final Constructor<?>	Returns: A no-arg constructor for the class; returns `null` if the class does not implement `java.io.Externalizable` newConstructorForExternalization(Class<?> the class to instantiate cl) Returns an accessible no-arg constructor for an externalizable class to be initialized using a public no-argument constructor.
public Constructor<?>	Returns: an accessible constructor newConstructorForSerialization(Class<?> the class to instantiate cl, Constructor<?> the constructor to call constructorToCall) Returns an accessible constructor capable of creating instances of the given class, initialized by the given constructor.
public final Constructor<?>	Returns: a no-arg constructor for the class or `null` if the class or supertypes do not have a suitable no-arg constructor newConstructorForSerialization(Class<?> the class to instantiate cl) Returns an accessible no-arg constructor for a class.
public final OptionalDataException	Returns: a new OptionalDataException newOptionalDataExceptionForSerialization(boolean the value of `eof` in the created OptionalDataException bool) Returns a new OptionalDataException with `eof` set to `true` or `false`.
public final MethodHandle	Returns: a direct MethodHandle for the `readObject` method of the class or `null` if the class does not have a `readObject` method readObjectForSerialization(Class<?> a Serializable class cl) Returns a direct MethodHandle for the `readObject` method on a Serializable class.
public final MethodHandle	Returns: a direct MethodHandle for the `readObjectNoData` method of the class or `null` if the class does not have a `readObjectNoData` method readObjectNoDataForSerialization(Class<?> a Serializable class cl) Returns a direct MethodHandle for the `readObjectNoData` method on a Serializable class.
public final MethodHandle	Returns: a direct MethodHandle for the `readResolve` method of the class or `null` if the class does not have a `readResolve` method readResolveForSerialization(Class<?> the Serializable class cl) Returns a direct MethodHandle for the `readResolve` method on a serializable class.
public final ObjectStreamField[]	Returns: the declared `serialPersistentFields` from a serializable class, or `null` if none is declared, the field is declared but not valid, or the class is not a valid serializable class serialPersistentFields(Class<?> a Serializable class cl) Returns the declared `serialPersistentFields` from a serializable class, or `null` if none is declared, the field is declared but not valid, or the class is not a valid serializable class.
public final MethodHandle	Returns: a direct MethodHandle for the `writeObject` method of the class or `null` if the class does not have a `writeObject` method writeObjectForSerialization(Class<?> a Serializable class cl) Returns a direct MethodHandle for the `writeObject` method on a Serializable class.
public final MethodHandle	Returns: a direct MethodHandle for the `writeReplace` method of the class or `null` if the class does not have a `writeReplace` method writeReplaceForSerialization(Class<?> the Serializable class cl) Returns a direct MethodHandle for the `writeReplace` method on a serializable class.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

delegate	back to summary
private static final ReflectionFactory delegate

soleInstance	back to summary
private static final ReflectionFactory soleInstance

ReflectionFactory	back to summary
private ReflectionFactory()

Method Detail

defaultReadObjectForSerialization back to summary

defaultReadObjectForSerialization	back to summary
public final MethodHandle defaultReadObjectForSerialization(Class<?> cl) Generate and return a direct MethodHandle which implements the general default behavior for serializable class's `readObject`. The generated method behaves in accordance with the Java Serialization specification's rules for that method. The generated method will invoke `ObjectInputStream#readFields()` to acquire the stream field values. The serialization fields of the class will then be populated from the stream values. Only fields which are eligible for default serialization will be populated. This includes only fields which are not `transient` and not `static` (even if the field is `final` or `private`). Requesting a default serialization method for a class in a disallowed category is not supported; `null` will be returned for such classes. The disallowed categories include (but are not limited to): Classes which do not implement `Serializable` Classes which implement `Externalizable` Classes which are specially handled by the Java Serialization specification, including record classes, enum constant classes, `Class`, `String`, array classes, reflection proxy classes, and hidden classes Classes which declare a valid `serialPersistentFields` value Any special types which may possibly be added to the JDK or the Java language in the future which in turn might require special handling by the provisions of the corresponding future version of the Java Serialization specification The generated method will accept the instance as its first argument and the `ObjectInputStream` as its second argument. The return type of the method is `void`. Parameters cl:Class<?> a Serializable class Returns:MethodHandle a direct MethodHandle for the synthetic `readObject` method or `null` if the class falls in a disallowed category Since 24

public final MethodHandle defaultReadObjectForSerialization(Class<?> cl)

Generate and return a direct MethodHandle which implements the general default behavior for serializable class's readObject. The generated method behaves in accordance with the Java Serialization specification's rules for that method.

The generated method will invoke ObjectInputStream#readFields() to acquire the stream field values. The serialization fields of the class will then be populated from the stream values.

Only fields which are eligible for default serialization will be populated. This includes only fields which are not transient and not static (even if the field is final or private).

Requesting a default serialization method for a class in a disallowed category is not supported; null will be returned for such classes. The disallowed categories include (but are not limited to):

Classes which do not implement Serializable
Classes which implement Externalizable
Classes which are specially handled by the Java Serialization specification, including record classes, enum constant classes, Class, String, array classes, reflection proxy classes, and hidden classes
Classes which declare a valid serialPersistentFields value
Any special types which may possibly be added to the JDK or the Java language in the future which in turn might require special handling by the provisions of the corresponding future version of the Java Serialization specification

The generated method will accept the instance as its first argument and the ObjectInputStream as its second argument. The return type of the method is void.

Parameters

cl:Class<?>: a Serializable class

Returns:MethodHandle

a direct MethodHandle for the synthetic readObject method or null if the class falls in a disallowed category

Since

defaultWriteObjectForSerialization back to summary

defaultWriteObjectForSerialization	back to summary
public final MethodHandle defaultWriteObjectForSerialization(Class<?> cl) Generate and return a direct MethodHandle which implements the general default behavior for serializable class's `writeObject`. The generated method behaves in accordance with the Java Serialization specification's rules for that method. The generated method will invoke `ObjectOutputStream#putFields` to acquire the buffer for the stream field values. The buffer will be populated from the serialization fields of the class. The buffer will then be flushed to the stream using the `ObjectOutputStream#writeFields()` method. Only fields which are eligible for default serialization will be written to the buffer. This includes only fields which are not `transient` and not `static` (even if the field is `final` or `private`). Requesting a default serialization method for a class in a disallowed category is not supported; `null` will be returned for such classes. The disallowed categories include (but are not limited to): Classes which do not implement `Serializable` Classes which implement `Externalizable` Classes which are specially handled by the Java Serialization specification, including record classes, enum constant classes, `Class`, `String`, array classes, reflection proxy classes, and hidden classes Classes which declare a valid `serialPersistentFields` value Any special types which may possibly be added to the JDK or the Java language in the future which in turn might require special handling by the provisions of the corresponding future version of the Java Serialization specification The generated method will accept the instance as its first argument and the `ObjectOutputStream` as its second argument. The return type of the method is `void`. Parameters cl:Class<?> a Serializable class Returns:MethodHandle a direct MethodHandle for the synthetic `writeObject` method or `null` if the class falls in a disallowed category Since 24

public final MethodHandle defaultWriteObjectForSerialization(Class<?> cl)

Generate and return a direct MethodHandle which implements the general default behavior for serializable class's writeObject. The generated method behaves in accordance with the Java Serialization specification's rules for that method.

The generated method will invoke ObjectOutputStream#putFields to acquire the buffer for the stream field values. The buffer will be populated from the serialization fields of the class. The buffer will then be flushed to the stream using the ObjectOutputStream#writeFields() method.

Only fields which are eligible for default serialization will be written to the buffer. This includes only fields which are not transient and not static (even if the field is final or private).

Requesting a default serialization method for a class in a disallowed category is not supported; null will be returned for such classes. The disallowed categories include (but are not limited to):

Classes which do not implement Serializable
Classes which implement Externalizable
Classes which are specially handled by the Java Serialization specification, including record classes, enum constant classes, Class, String, array classes, reflection proxy classes, and hidden classes
Classes which declare a valid serialPersistentFields value
Any special types which may possibly be added to the JDK or the Java language in the future which in turn might require special handling by the provisions of the corresponding future version of the Java Serialization specification

The generated method will accept the instance as its first argument and the ObjectOutputStream as its second argument. The return type of the method is void.

Parameters

cl:Class<?>: a Serializable class

Returns:MethodHandle

a direct MethodHandle for the synthetic writeObject method or null if the class falls in a disallowed category

Since

getReflectionFactory back to summary

getReflectionFactory	back to summary
public static ReflectionFactory getReflectionFactory() Provides the caller with the capability to instantiate reflective objects. The returned `ReflectionFactory` object should be carefully guarded by the caller, since it can be used to read and write private data and invoke private methods, as well as to load unverified bytecodes. It must never be passed to untrusted code. Returns:ReflectionFactory the ReflectionFactory

public static ReflectionFactory getReflectionFactory()

Provides the caller with the capability to instantiate reflective objects.

The returned ReflectionFactory object should be carefully guarded by the caller, since it can be used to read and write private data and invoke private methods, as well as to load unverified bytecodes. It must never be passed to untrusted code.

Returns:ReflectionFactory: the ReflectionFactory

hasStaticInitializerForSerialization back to summary

hasStaticInitializerForSerialization	back to summary
public final boolean hasStaticInitializerForSerialization(Class<?> cl) Returns true if the class has a static initializer. The presence of a static initializer is used to compute the serialVersionUID. Parameters cl:Class<?> a serializable class Returns:boolean `true` if the class has a static initializer, otherwise `false`

public final boolean hasStaticInitializerForSerialization(Class<?> cl)

Returns true if the class has a static initializer. The presence of a static initializer is used to compute the serialVersionUID.

Parameters

cl:Class<?>: a serializable class

Returns:boolean

true if the class has a static initializer, otherwise false

newConstructorForExternalization back to summary

newConstructorForExternalization	back to summary
public final Constructor<?> newConstructorForExternalization(Class<?> cl) Returns an accessible no-arg constructor for an externalizable class to be initialized using a public no-argument constructor. Parameters cl:Class<?> the class to instantiate Returns:Constructor<?> A no-arg constructor for the class; returns `null` if the class does not implement `java.io.Externalizable`

public final Constructor<?> newConstructorForExternalization(Class<?> cl)

Returns an accessible no-arg constructor for an externalizable class to be initialized using a public no-argument constructor.

Parameters

cl:Class<?>: the class to instantiate

Returns:Constructor<?>

A no-arg constructor for the class; returns null if the class does not implement java.io.Externalizable

newConstructorForSerialization	back to summary
public Constructor<?> newConstructorForSerialization(Class<?> cl, Constructor<?> constructorToCall) Returns an accessible constructor capable of creating instances of the given class, initialized by the given constructor. Parameters cl:Class<?> the class to instantiate constructorToCall:Constructor<?> the constructor to call Returns:Constructor<?> an accessible constructor

newConstructorForSerialization

back to summary

public Constructor<?> newConstructorForSerialization(Class<?> cl, Constructor<?> constructorToCall)

Returns an accessible constructor capable of creating instances of the given class, initialized by the given constructor.

Parameters

cl:Class<?>: the class to instantiate
constructorToCall:Constructor<?>: the constructor to call

Returns:Constructor<?>

an accessible constructor

newConstructorForSerialization back to summary

newConstructorForSerialization	back to summary
public final Constructor<?> newConstructorForSerialization(Class<?> cl) Returns an accessible no-arg constructor for a class. The no-arg constructor is found searching the class and its supertypes. Parameters cl:Class<?> the class to instantiate Returns:Constructor<?> a no-arg constructor for the class or `null` if the class or supertypes do not have a suitable no-arg constructor

public final Constructor<?> newConstructorForSerialization(Class<?> cl)

Returns an accessible no-arg constructor for a class. The no-arg constructor is found searching the class and its supertypes.

Parameters

cl:Class<?>: the class to instantiate

Returns:Constructor<?>

a no-arg constructor for the class or null if the class or supertypes do not have a suitable no-arg constructor

newOptionalDataExceptionForSerialization back to summary

newOptionalDataExceptionForSerialization	back to summary
public final OptionalDataException newOptionalDataExceptionForSerialization(boolean bool) Returns a new OptionalDataException with `eof` set to `true` or `false`. Parameters bool:boolean the value of `eof` in the created OptionalDataException Returns:OptionalDataException a new OptionalDataException

public final OptionalDataException newOptionalDataExceptionForSerialization(boolean bool)

Returns a new OptionalDataException with eof set to true or false.

Parameters

bool:boolean: the value of eof in the created OptionalDataException

Returns:OptionalDataException

a new OptionalDataException

readObjectForSerialization back to summary

readObjectForSerialization	back to summary
public final MethodHandle readObjectForSerialization(Class<?> cl) Returns a direct MethodHandle for the `readObject` method on a Serializable class. The first argument of `MethodHandle#invoke` is the serializable object and the second argument is the `ObjectInputStream` passed to `readObject`. Parameters cl:Class<?> a Serializable class Returns:MethodHandle a direct MethodHandle for the `readObject` method of the class or `null` if the class does not have a `readObject` method

public final MethodHandle readObjectForSerialization(Class<?> cl)

Returns a direct MethodHandle for the readObject method on a Serializable class. The first argument of MethodHandle#invoke is the serializable object and the second argument is the ObjectInputStream passed to readObject.

Parameters

cl:Class<?>: a Serializable class

Returns:MethodHandle

a direct MethodHandle for the readObject method of the class or null if the class does not have a readObject method

readObjectNoDataForSerialization back to summary

readObjectNoDataForSerialization	back to summary
public final MethodHandle readObjectNoDataForSerialization(Class<?> cl) Returns a direct MethodHandle for the `readObjectNoData` method on a Serializable class. The only argument of `MethodHandle#invoke` is the serializable object, which `readObjectNoData` is called on. No arguments are passed to the `readObjectNoData` method. Parameters cl:Class<?> a Serializable class Returns:MethodHandle a direct MethodHandle for the `readObjectNoData` method of the class or `null` if the class does not have a `readObjectNoData` method

public final MethodHandle readObjectNoDataForSerialization(Class<?> cl)

Returns a direct MethodHandle for the readObjectNoData method on a Serializable class. The only argument of MethodHandle#invoke is the serializable object, which readObjectNoData is called on. No arguments are passed to the readObjectNoData method.

Parameters

cl:Class<?>: a Serializable class

Returns:MethodHandle

a direct MethodHandle for the readObjectNoData method of the class or null if the class does not have a readObjectNoData method

readResolveForSerialization back to summary

readResolveForSerialization	back to summary
public final MethodHandle readResolveForSerialization(Class<?> cl) Returns a direct MethodHandle for the `readResolve` method on a serializable class. The single argument of `MethodHandle#invoke` is the serializable object. Parameters cl:Class<?> the Serializable class Returns:MethodHandle a direct MethodHandle for the `readResolve` method of the class or `null` if the class does not have a `readResolve` method

public final MethodHandle readResolveForSerialization(Class<?> cl)

Returns a direct MethodHandle for the readResolve method on a serializable class. The single argument of MethodHandle#invoke is the serializable object.

Parameters

cl:Class<?>: the Serializable class

Returns:MethodHandle

a direct MethodHandle for the readResolve method of the class or null if the class does not have a readResolve method

serialPersistentFields back to summary

serialPersistentFields	back to summary
public final ObjectStreamField[] serialPersistentFields(Class<?> cl) Returns the declared `serialPersistentFields` from a serializable class, or `null` if none is declared, the field is declared but not valid, or the class is not a valid serializable class. A class is a valid serializable class if it implements `Serializable` but not `Externalizable`. The `serialPersistentFields` field is valid if it meets the type and accessibility restrictions defined by the Java Serialization specification. Parameters cl:Class<?> a Serializable class Returns:ObjectStreamField[] the declared `serialPersistentFields` from a serializable class, or `null` if none is declared, the field is declared but not valid, or the class is not a valid serializable class Since 24

public final ObjectStreamField[] serialPersistentFields(Class<?> cl)

Returns the declared serialPersistentFields from a serializable class, or null if none is declared, the field is declared but not valid, or the class is not a valid serializable class. A class is a valid serializable class if it implements Serializable but not Externalizable. The serialPersistentFields field is valid if it meets the type and accessibility restrictions defined by the Java Serialization specification.

Parameters

cl:Class<?>: a Serializable class

Returns:ObjectStreamField[]

the declared serialPersistentFields from a serializable class, or null if none is declared, the field is declared but not valid, or the class is not a valid serializable class

Since

writeObjectForSerialization back to summary

writeObjectForSerialization	back to summary
public final MethodHandle writeObjectForSerialization(Class<?> cl) Returns a direct MethodHandle for the `writeObject` method on a Serializable class. The first argument of `MethodHandle#invoke` is the serializable object and the second argument is the `ObjectOutputStream` passed to `writeObject`. Parameters cl:Class<?> a Serializable class Returns:MethodHandle a direct MethodHandle for the `writeObject` method of the class or `null` if the class does not have a `writeObject` method

public final MethodHandle writeObjectForSerialization(Class<?> cl)

Returns a direct MethodHandle for the writeObject method on a Serializable class. The first argument of MethodHandle#invoke is the serializable object and the second argument is the ObjectOutputStream passed to writeObject.

Parameters

cl:Class<?>: a Serializable class

Returns:MethodHandle

a direct MethodHandle for the writeObject method of the class or null if the class does not have a writeObject method

writeReplaceForSerialization back to summary

writeReplaceForSerialization	back to summary
public final MethodHandle writeReplaceForSerialization(Class<?> cl) Returns a direct MethodHandle for the `writeReplace` method on a serializable class. The single argument of `MethodHandle#invoke` is the serializable object. Parameters cl:Class<?> the Serializable class Returns:MethodHandle a direct MethodHandle for the `writeReplace` method of the class or `null` if the class does not have a `writeReplace` method

public final MethodHandle writeReplaceForSerialization(Class<?> cl)

Returns a direct MethodHandle for the writeReplace method on a serializable class. The single argument of MethodHandle#invoke is the serializable object.

Parameters

cl:Class<?>: the Serializable class

Returns:MethodHandle

a direct MethodHandle for the writeReplace method of the class or null if the class does not have a writeReplace method

public Class ReflectionFactory

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