Interface ClassTransform

All Superinterfaces:

ClassFileTransform<ClassTransform, ClassElement, ClassBuilder>

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public non-sealed interface ClassTransform
extends ClassFileTransform<ClassTransform, ClassElement, ClassBuilder>

A transformation on streams of ClassElement.

Refer to ClassFileTransform for general guidance and caution around the use of transforms for structures in the class file format.

Since:

24

See Also:

• ClassModel
• ClassFile.transformClass(ClassModel, ClassTransform)

Field Summary

Fields

Modifier and Type	Field	Description
static final ClassTransform	ACCEPT_ALL	A class transform that passes all elements to the builder.

Method Summary

Modifier and Type	Method	Description
default ClassTransform	andThen(ClassTransform t)	Chain this transform with another; elements presented to the builder of this transform will become the input to the next transform.
static ClassTransform	dropping(Predicate<ClassElement> filter)	Creates a class transform that passes each element through to the builder, except for those that the supplied Predicate returns true for.
static ClassTransform	endHandler(Consumer<ClassBuilder> finisher)	Creates a class transform that passes each element through to the builder, and calls the specified function when transformation is complete.
static ClassTransform	ofStateful(Supplier<ClassTransform> supplier)	Creates a stateful class transform from a Supplier.
static ClassTransform	transformingFields(FieldTransform xform)	Creates a class transform that transforms FieldModel elements with the supplied field transform, passing other elements through to the builder.
static ClassTransform	transformingMethodBodies(CodeTransform xform)	Creates a class transform that transforms the CodeAttribute (method body) of MethodModel elements with the supplied code transform, passing other elements through to the builder.
static ClassTransform	transformingMethodBodies(Predicate<MethodModel> filter, CodeTransform xform)	Creates a class transform that transforms the CodeAttribute (method body) of MethodModel elements with the supplied code transform for methods that the supplied Predicate returns true for, passing other elements through to the builder.
static ClassTransform	transformingMethods(MethodTransform xform)	Creates a class transform that transforms MethodModel elements with the supplied method transform, passing other elements through to the builder.
static ClassTransform	transformingMethods(Predicate<MethodModel> filter, MethodTransform xform)	Creates a class transform that transforms MethodModel elements with the supplied method transform for methods that the supplied Predicate returns true for, passing other elements through to the builder.

Methods declared in interface ClassFileTransform

accept, atEnd, atStart

Modifier and Type	Method	Description
void	accept(ClassBuilder builder, ClassElement element)	Transform an element by taking the appropriate actions on the builder.
default void	atEnd(ClassBuilder builder)	Take any final action during transformation of a classfile entity.
default void	atStart(ClassBuilder builder)	Take any preliminary action during transformation of a classfile entity.

Field Details

ACCEPT_ALL

static final ClassTransform ACCEPT_ALL

A class transform that passes all elements to the builder.

Method Details

ofStateful

static ClassTransform ofStateful(Supplier<ClassTransform> supplier)

Creates a stateful class transform from a Supplier. The supplier will be invoked for each transformation.

Parameters:

supplier - a Supplier that produces a fresh transform object for each traversal

Returns:

the stateful class transform

endHandler

static ClassTransform endHandler(Consumer<ClassBuilder> finisher)

Creates a class transform that passes each element through to the builder, and calls the specified function when transformation is complete.

Parameters:

finisher - the function to call when transformation is complete

Returns:

the class transform

dropping

static ClassTransform dropping(Predicate<ClassElement> filter)

Creates a class transform that passes each element through to the builder, except for those that the supplied Predicate returns true for.

Parameters:

filter - the predicate that determines which elements to drop

Returns:

the class transform

transformingMethods

static ClassTransform transformingMethods(Predicate<MethodModel> filter,
 MethodTransform xform)

Creates a class transform that transforms MethodModel elements with the supplied method transform for methods that the supplied Predicate returns true for, passing other elements through to the builder.

Parameters:

filter - a predicate that determines which methods to transform

xform - the method transform

Returns:

the class transform

transformingMethods

static ClassTransform transformingMethods(MethodTransform xform)

Creates a class transform that transforms MethodModel elements with the supplied method transform, passing other elements through to the builder.

Parameters:

xform - the method transform

Returns:

the class transform

transformingMethodBodies

static ClassTransform transformingMethodBodies(Predicate<MethodModel> filter,
 CodeTransform xform)

Creates a class transform that transforms the CodeAttribute (method body) of MethodModel elements with the supplied code transform for methods that the supplied Predicate returns true for, passing other elements through to the builder.

Parameters:

filter - a predicate that determines which methods to transform

xform - the code transform

Returns:

the class transform

transformingMethodBodies

static ClassTransform transformingMethodBodies(CodeTransform xform)

Creates a class transform that transforms the CodeAttribute (method body) of MethodModel elements with the supplied code transform, passing other elements through to the builder.

Parameters:

xform - the code transform

Returns:

the class transform

transformingFields

static ClassTransform transformingFields(FieldTransform xform)

Creates a class transform that transforms FieldModel elements with the supplied field transform, passing other elements through to the builder.

Parameters:

xform - the field transform

Returns:

the class transform

andThen

default ClassTransform andThen(ClassTransform t)

Description copied from interface: ClassFileTransform

Chain this transform with another; elements presented to the builder of this transform will become the input to the next transform.

This method is implemented by the Class-File API. Users usually don't have sufficient access to Class-File API functionalities to override this method correctly for generic downstream transforms.

Specified by:

andThen in interface ClassFileTransform<ClassTransform, ClassElement, ClassBuilder>

Implementation Requirements:

The default implementation returns this class transform chained with another class transform from the argument. Chaining of two transforms requires to involve a chained builder serving as a target builder for this transform and also as a source of elements for the downstream transform.

Parameters:

t - the downstream transform

Returns:

the chained transform