Package io.quarkus.gizmo

Class ClassTransformer

java.lang.Object

io.quarkus.gizmo.ClassTransformer

public class ClassTransformer
extends java.lang.Object

Transforms an existing class by wrapping an ASM ClassVisitor. The applyTo(ClassVisitor) method must be called before the wrapped ClassVisitor is visited and the result should be used instead of the original visitor.

In other words, this class acts like a builder. First, the class transformation must be described by calling addInterface(), addMethod(), addField(), modifyMethod(), modifyField(), etc. Then, a ClassVisitor must be created using applyTo(). Afterwards, the ClassTransformer instance should be discarded.

If a modification of a class member and an addition of a class member of the same kind, with the same name and the same descriptor are configured, the modification is performed prior to the addition. (It follows that the modify* methods may not be used to alter members created using the add* methods.) No other ordering guarantees are made.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	ClassTransformer.NamedDescriptor

Field Summary

Fields

Modifier and Type	Field	Description
private java.util.Map<FieldDescriptor,FieldCreatorImpl>	addedFields
private java.util.Set<java.lang.String>	addedInterfaces
private java.util.Map<MethodDescriptor,ClassTransfromerMethodCreatorImpl>	addedMethods
private int	addedModifiers
private java.lang.String	className
private java.util.Map<ClassTransformer.NamedDescriptor,FieldTransformer>	modifiedFields
private java.util.Map<ClassTransformer.NamedDescriptor,MethodTransformer>	modifiedMethods
private java.util.Set<ClassTransformer.NamedDescriptor>	removedFields
private java.util.Set<ClassTransformer.NamedDescriptor>	removedMethods
private int	removedModifiers

Constructor Summary

Constructors

Constructor	Description
ClassTransformer(java.lang.String className)

Method Summary

Modifier and Type	Method	Description
FieldCreator	addField(FieldDescriptor fieldDescriptor)	Returns a FieldCreator to configure a new field that will be added to this class.
FieldCreator	addField(java.lang.String name, java.lang.Object type)	Returns a FieldCreator to configure a new field that will be added to this class.
void	addInterface(java.lang.Object interfaceName)	Adds given interfaceName to the set of interfaces implemented by this class.
MethodCreator	addMethod(MethodDescriptor methodDescriptor)	Returns a MethodCreator to configure a new method that will be added to this class.
MethodCreator	addMethod(java.lang.String name, java.lang.Object returnType, java.lang.Object... parameters)	Returns a MethodCreator to configure a new method that will be added to this class.
void	addModifiers(int modifiers)	Adds given modifiers to the modifiers of this class.
org.objectweb.asm.ClassVisitor	applyTo(org.objectweb.asm.ClassVisitor visitor)	Returns a ClassVisitor that applies the class transformation to given visitor.
(package private) java.lang.String	getClassName()
(package private) boolean	hasAddedMethod(MethodDescriptor methodDescriptor)
FieldTransformer	modifyField(FieldDescriptor field)	Returns a FieldTransformer to configure a transformation of given field.
FieldTransformer	modifyField(java.lang.String name, java.lang.Object type)	Returns a FieldTransformer to configure a transformation of a field with given name and type.
MethodTransformer	modifyMethod(MethodDescriptor method)	Returns a MethodTransformer to configure a transformation of given method.
MethodTransformer	modifyMethod(java.lang.String name, java.lang.Object returnType, java.lang.Object... parameters)	Returns a MethodTransformer to configure a transformation of a method with given name, returnType and parameters.
void	removeField(FieldDescriptor field)	Removes the given field.
void	removeField(java.lang.String name, java.lang.Object type)	Removes the field of the given name and type.
void	removeMethod(MethodDescriptor method)	Removes the given method.
void	removeMethod(java.lang.String name, java.lang.Object returnType, java.lang.Object... parameters)	Removes the method with the given name, return type and parameters.
void	removeModifiers(int modifiers)	Removes given modifiers from the modifiers of this class.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

className

private final java.lang.String className

addedModifiers

private int addedModifiers

removedModifiers

private int removedModifiers

addedInterfaces

private final java.util.Set<java.lang.String> addedInterfaces

addedMethods

private final java.util.Map<MethodDescriptor,ClassTransfromerMethodCreatorImpl> addedMethods

addedFields

private final java.util.Map<FieldDescriptor,FieldCreatorImpl> addedFields

modifiedMethods

private final java.util.Map<ClassTransformer.NamedDescriptor,MethodTransformer> modifiedMethods

modifiedFields

private final java.util.Map<ClassTransformer.NamedDescriptor,FieldTransformer> modifiedFields

removedMethods

private final java.util.Set<ClassTransformer.NamedDescriptor> removedMethods

removedFields

private final java.util.Set<ClassTransformer.NamedDescriptor> removedFields

Constructor Detail

ClassTransformer

public ClassTransformer(java.lang.String className)

Parameters:

className - the name of the transformed class

Method Detail

getClassName

java.lang.String getClassName()

hasAddedMethod

boolean hasAddedMethod(MethodDescriptor methodDescriptor)

addModifiers

public void addModifiers(int modifiers)

Adds given modifiers to the modifiers of this class. It is a responsibility of the caller to make sure the resulting set of modifiers is valid.

Parameters:

modifiers - the modifiers to add to this class

removeModifiers

public void removeModifiers(int modifiers)

Removes given modifiers from the modifiers of this class. It is a responsibility of the caller to make sure the resulting set of modifiers is valid.

Parameters:

modifiers - the modifiers to remove from this class

addInterface

public void addInterface(java.lang.Object interfaceName)

Adds given interfaceName to the set of interfaces implemented by this class. It is a responsibility of the caller to make sure the class in fact implements the interface, typically by adding all the methods with addMethod().

Adding an interface that has already been added is a noop, as well as adding an interface that the original class already implements.

Parameters:

interfaceName - the interface type to add

Throws:

java.lang.IllegalArgumentException - if the interfaceName is not a Class or String

addMethod

public MethodCreator addMethod(MethodDescriptor methodDescriptor)

Returns a MethodCreator to configure a new method that will be added to this class.

The BytecodeCreator.createFunction(Class) method may not be used, as creating new class would be required.

Parameters:

methodDescriptor - descriptor of the new method

Returns:

a new MethodCreator

addMethod

public MethodCreator addMethod(java.lang.String name,
                               java.lang.Object returnType,
                               java.lang.Object... parameters)

Returns a MethodCreator to configure a new method that will be added to this class.

The BytecodeCreator.createFunction(Class) method may not be used, as creating new class would be required.

Parameters:

name - name of the new method

returnType - return type of the new method

parameters - parameter types of the new method

Returns:

a new MethodCreator

Throws:

java.lang.IllegalArgumentException - if the returnType or any of the parameters is not a Class or String

removeMethod

public void removeMethod(java.lang.String name,
                         java.lang.Object returnType,
                         java.lang.Object... parameters)

Removes the method with the given name, return type and parameters.

It's illegal to remove a modified method.

Parameters:

name -

returnType -

parameters -

Throws:

java.lang.IllegalArgumentException - if the returnType or any of the parameters is not a Class or String

removeMethod

public void removeMethod(MethodDescriptor method)

Removes the given method.

It's illegal to remove a modified method.

Parameters:

method -

addField

public FieldCreator addField(FieldDescriptor fieldDescriptor)

Returns a FieldCreator to configure a new field that will be added to this class.

Parameters:

fieldDescriptor - descriptor of the new field

Returns:

a new FieldCreator

addField

public FieldCreator addField(java.lang.String name,
                             java.lang.Object type)

Returns a FieldCreator to configure a new field that will be added to this class.

Parameters:

name - name of the new field

type - type of the new field

Returns:

a new FieldCreator

Throws:

java.lang.IllegalArgumentException - if the type is not a Class or String

removeField

public void removeField(java.lang.String name,
                        java.lang.Object type)

Removes the field of the given name and type.

It's illegal to remove a modified field.

Parameters:

name -

type -

Throws:

java.lang.IllegalArgumentException - if the type is not a Class or String

removeField

public void removeField(FieldDescriptor field)

Removes the given field.

It's illegal to remove a modified field.

Parameters:

field -

modifyMethod

public MethodTransformer modifyMethod(MethodDescriptor method)

Returns a MethodTransformer to configure a transformation of given method.

It's illegal to modify a removed method.

Parameters:

method - descriptor of the method to transform

Returns:

a MethodTransformer

modifyMethod

public MethodTransformer modifyMethod(java.lang.String name,
                                      java.lang.Object returnType,
                                      java.lang.Object... parameters)

Returns a MethodTransformer to configure a transformation of a method with given name, returnType and parameters.

It's illegal to modify a removed method.

Parameters:

name - name of the method

returnType - return type of the method

parameters - parameter types of the method

Returns:

a MethodTransformer

Throws:

java.lang.IllegalArgumentException - if the returnType or any of the parameters is not a Class or String

modifyField

public FieldTransformer modifyField(FieldDescriptor field)

Returns a FieldTransformer to configure a transformation of given field.

It's illegal to modify a removed field.

Parameters:

field - descriptor of the field to transform

Returns:

a FieldTransformer

modifyField

public FieldTransformer modifyField(java.lang.String name,
                                    java.lang.Object type)

Returns a FieldTransformer to configure a transformation of a field with given name and type.

It's illegal to modify a removed field.

Parameters:

name - name of the field

type - type of the field

Returns:

a FieldTransformer

Throws:

java.lang.IllegalArgumentException - if the type is not a Class or String

applyTo

public org.objectweb.asm.ClassVisitor applyTo(org.objectweb.asm.ClassVisitor visitor)

Returns a ClassVisitor that applies the class transformation to given visitor. At the moment this method is called, no visit* method must have been called on given visitor. The transformation is not finished until visitEnd() is called on the resulting visitor.

Parameters:

visitor - the ClassVisitor to which the transformation is applied

Returns:

the transforming ClassVisitor