net.bytebuddy.implementation.bind.annotation.FieldProxy Maven / Gradle / Ivy
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/*
* Copyright 2014 - Present Rafael Winterhalter
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.bytebuddy.implementation.bind.annotation;
import net.bytebuddy.ByteBuddy;
import net.bytebuddy.ClassFileVersion;
import net.bytebuddy.build.HashCodeAndEqualsPlugin;
import net.bytebuddy.description.annotation.AnnotationDescription;
import net.bytebuddy.description.field.FieldDescription;
import net.bytebuddy.description.method.MethodDescription;
import net.bytebuddy.description.method.MethodList;
import net.bytebuddy.description.method.ParameterDescription;
import net.bytebuddy.description.type.TypeDescription;
import net.bytebuddy.dynamic.DynamicType;
import net.bytebuddy.dynamic.scaffold.InstrumentedType;
import net.bytebuddy.dynamic.scaffold.TypeValidation;
import net.bytebuddy.dynamic.scaffold.subclass.ConstructorStrategy;
import net.bytebuddy.implementation.ExceptionMethod;
import net.bytebuddy.implementation.Implementation;
import net.bytebuddy.implementation.MethodAccessorFactory;
import net.bytebuddy.implementation.auxiliary.AuxiliaryType;
import net.bytebuddy.implementation.bind.MethodDelegationBinder;
import net.bytebuddy.implementation.bytecode.ByteCodeAppender;
import net.bytebuddy.implementation.bytecode.Duplication;
import net.bytebuddy.implementation.bytecode.StackManipulation;
import net.bytebuddy.implementation.bytecode.TypeCreation;
import net.bytebuddy.implementation.bytecode.assign.Assigner;
import net.bytebuddy.implementation.bytecode.member.FieldAccess;
import net.bytebuddy.implementation.bytecode.member.MethodInvocation;
import net.bytebuddy.implementation.bytecode.member.MethodReturn;
import net.bytebuddy.implementation.bytecode.member.MethodVariableAccess;
import net.bytebuddy.utility.RandomString;
import net.bytebuddy.jar.asm.MethodVisitor;
import net.bytebuddy.jar.asm.Opcodes;
import java.io.Serializable;
import java.lang.annotation.*;
import java.util.Collections;
import static net.bytebuddy.matcher.ElementMatchers.*;
/**
* Using this annotation it is possible to access fields by getter and setter types. Before this annotation can be
* used, it needs to be installed with two types. The getter type must be defined in a single-method interface
* with a single method that returns an {@link java.lang.Object} type and takes no arguments. The setter interface
* must similarly return {@code void} and take a single {@link java.lang.Object} argument. After installing these
* interfaces with the {@link FieldProxy.Binder}, this
* binder needs to be registered with a {@link net.bytebuddy.implementation.MethodDelegation} before it can be used.
*
* @see net.bytebuddy.implementation.MethodDelegation
* @see net.bytebuddy.implementation.bind.annotation.TargetMethodAnnotationDrivenBinder
*/
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.PARAMETER)
public @interface FieldProxy {
/**
* Determines if the proxy should be serializable.
*
* @return {@code true} if the proxy should be serializable.
*/
boolean serializableProxy() default false;
/**
* Determines the name of the field that is to be accessed. If this property is not set, a field name is inferred
* by the intercepted method after the Java beans naming conventions.
*
* @return The name of the field to be accessed.
*/
String value() default TargetMethodAnnotationDrivenBinder.ParameterBinder.ForFieldBinding.BEAN_PROPERTY;
/**
* Determines which type defines the field that is to be accessed. If this property is not set, the most field
* that is defined highest in the type hierarchy is accessed.
*
* @return The type that defines the accessed field.
*/
Class declaringType() default void.class;
/**
* A binder for the {@link FieldProxy} annotation.
*/
@HashCodeAndEqualsPlugin.Enhance
class Binder extends TargetMethodAnnotationDrivenBinder.ParameterBinder.ForFieldBinding {
/**
* A reference to the method that declares the field annotation's defining type property.
*/
private static final MethodDescription.InDefinedShape DECLARING_TYPE;
/**
* A reference to the method that declares the field annotation's field name property.
*/
private static final MethodDescription.InDefinedShape FIELD_NAME;
/**
* A reference to the method that declares the field annotation's serializable proxy property.
*/
private static final MethodDescription.InDefinedShape SERIALIZABLE_PROXY;
/*
* Fetches a reference to all annotation properties.
*/
static {
MethodList methodList = TypeDescription.ForLoadedType.of(FieldProxy.class).getDeclaredMethods();
DECLARING_TYPE = methodList.filter(named("declaringType")).getOnly();
FIELD_NAME = methodList.filter(named("value")).getOnly();
SERIALIZABLE_PROXY = methodList.filter(named("serializableProxy")).getOnly();
}
/**
* Creates a binder by installing a single proxy type where annotating a parameter with {@link FieldProxy} allows
* getting and setting values for a given field.
*
* @param type A type which declares exactly one abstract getter and an abstract setter for the {@link Object}
* type. The type is allowed to be generic.
* @return A binder for the {@link FieldProxy} annotation.
*/
public static TargetMethodAnnotationDrivenBinder.ParameterBinder install(Class type) {
return install(TypeDescription.ForLoadedType.of(type));
}
/**
* Creates a binder by installing a single proxy type where annotating a parameter with {@link FieldProxy} allows
* getting and setting values for a given field.
*
* @param typeDescription A type which declares exactly one abstract getter and an abstract setter for the {@link Object}
* type. The type is allowed to be generic.
* @return A binder for the {@link FieldProxy} annotation.
*/
public static TargetMethodAnnotationDrivenBinder.ParameterBinder install(TypeDescription typeDescription) {
if (!typeDescription.isInterface()) {
throw new IllegalArgumentException(typeDescription + " is not an interface");
} else if (!typeDescription.getInterfaces().isEmpty()) {
throw new IllegalArgumentException(typeDescription + " must not extend other interfaces");
} else if (!typeDescription.isPublic()) {
throw new IllegalArgumentException(typeDescription + " is not public");
}
MethodList methodCandidates = typeDescription.getDeclaredMethods().filter(isAbstract());
if (methodCandidates.size() != 2) {
throw new IllegalArgumentException(typeDescription + " does not declare exactly two non-abstract methods");
}
MethodList getterCandidates = methodCandidates.filter(isGetter(Object.class));
if (getterCandidates.size() != 1) {
throw new IllegalArgumentException(typeDescription + " does not declare a getter with an Object type");
}
MethodList setterCandidates = methodCandidates.filter(isSetter(Object.class));
if (setterCandidates.size() != 1) {
throw new IllegalArgumentException(typeDescription + " does not declare a setter with an Object type");
}
return new Binder(typeDescription, getterCandidates.getOnly(), setterCandidates.getOnly());
}
/**
* Creates a binder by installing two proxy types which are implemented by this binder if a field getter
* or a field setter is requested by using the
* {@link FieldProxy} annotation.
*
* @param getterType The type which should be used for getter proxies. The type must
* represent an interface which defines a single method which returns an
* {@link java.lang.Object} return type and does not take any arguments. The use of generics
* is permitted.
* @param setterType The type which should be uses for setter proxies. The type must
* represent an interface which defines a single method which returns {@code void}
* and takes a single {@link java.lang.Object}-typed argument. The use of generics
* is permitted.
* @return A binder for the {@link FieldProxy} annotation.
*/
public static TargetMethodAnnotationDrivenBinder.ParameterBinder install(Class getterType, Class setterType) {
return install(TypeDescription.ForLoadedType.of(getterType), TypeDescription.ForLoadedType.of(setterType));
}
/**
* Creates a binder by installing two proxy types which are implemented by this binder if a field getter
* or a field setter is requested by using the
* {@link FieldProxy} annotation.
*
* @param getterType The type which should be used for getter proxies. The type must
* represent an interface which defines a single method which returns an
* {@link java.lang.Object} return type and does not take any arguments. The use of generics
* is permitted.
* @param setterType The type which should be uses for setter proxies. The type must
* represent an interface which defines a single method which returns {@code void}
* and takes a single {@link java.lang.Object}-typed argument. The use of generics
* is permitted.
* @return A binder for the {@link FieldProxy} annotation.
*/
public static TargetMethodAnnotationDrivenBinder.ParameterBinder install(TypeDescription getterType, TypeDescription setterType) {
MethodDescription.InDefinedShape getterMethod = onlyMethod(getterType);
if (!getterMethod.getReturnType().asErasure().represents(Object.class)) {
throw new IllegalArgumentException(getterMethod + " must take a single Object-typed parameter");
} else if (getterMethod.getParameters().size() != 0) {
throw new IllegalArgumentException(getterMethod + " must not declare parameters");
}
MethodDescription.InDefinedShape setterMethod = onlyMethod(setterType);
if (!setterMethod.getReturnType().asErasure().represents(void.class)) {
throw new IllegalArgumentException(setterMethod + " must return void");
} else if (setterMethod.getParameters().size() != 1 || !setterMethod.getParameters().get(0).getType().asErasure().represents(Object.class)) {
throw new IllegalArgumentException(setterMethod + " must declare a single Object-typed parameters");
}
return new Binder(getterMethod, setterMethod);
}
/**
* Extracts the only method from a given type description which is validated for the required properties for
* using the type as a proxy base type.
*
* @param typeDescription The type description to evaluate.
* @return The only method which was found to be compatible to the proxy requirements.
*/
private static MethodDescription.InDefinedShape onlyMethod(TypeDescription typeDescription) {
if (!typeDescription.isInterface()) {
throw new IllegalArgumentException(typeDescription + " is not an interface");
} else if (!typeDescription.getInterfaces().isEmpty()) {
throw new IllegalArgumentException(typeDescription + " must not extend other interfaces");
} else if (!typeDescription.isPublic()) {
throw new IllegalArgumentException(typeDescription + " is not public");
}
MethodList methodCandidates = typeDescription.getDeclaredMethods().filter(isAbstract());
if (methodCandidates.size() != 1) {
throw new IllegalArgumentException(typeDescription + " must declare exactly one abstract method");
}
return methodCandidates.getOnly();
}
/**
* The field resolver factory to apply by this binder.
*/
private final FieldResolver.Factory fieldResolverFactory;
/**
* Creates a new binder for a {@link FieldProxy} in simplex mode.
*
* @param getterMethod The getter method.
* @param setterMethod The setter method.
*/
protected Binder(MethodDescription.InDefinedShape getterMethod, MethodDescription.InDefinedShape setterMethod) {
this(new FieldResolver.Factory.Simplex(getterMethod, setterMethod));
}
/**
* Creates a new binder for a {@link FieldProxy} in duplex mode.
*
* @param proxyType The proxy type.
* @param getterMethod The getter method.
* @param setterMethod The setter method.
*/
protected Binder(TypeDescription proxyType, MethodDescription.InDefinedShape getterMethod, MethodDescription.InDefinedShape setterMethod) {
this(new FieldResolver.Factory.Duplex(proxyType, getterMethod, setterMethod));
}
/**
* Creates a new binder for a {@link FieldProxy}.
*
* @param fieldResolverFactory The field resolver factory to apply by this binder.
*/
protected Binder(FieldResolver.Factory fieldResolverFactory) {
this.fieldResolverFactory = fieldResolverFactory;
}
/**
* {@inheritDoc}
*/
public Class getHandledType() {
return FieldProxy.class;
}
@Override
protected String fieldName(AnnotationDescription.Loadable annotation) {
return annotation.getValue(FIELD_NAME).resolve(String.class);
}
@Override
protected TypeDescription declaringType(AnnotationDescription.Loadable annotation) {
return annotation.getValue(DECLARING_TYPE).resolve(TypeDescription.class);
}
@Override
protected MethodDelegationBinder.ParameterBinding bind(FieldDescription fieldDescription,
AnnotationDescription.Loadable annotation,
MethodDescription source,
ParameterDescription target,
Implementation.Target implementationTarget,
Assigner assigner) {
FieldResolver fieldResolver = fieldResolverFactory.resolve(target.getType().asErasure(), fieldDescription);
if (fieldResolver.isResolved()) {
return new MethodDelegationBinder.ParameterBinding.Anonymous(new AccessorProxy(fieldDescription,
implementationTarget.getInstrumentedType(),
fieldResolver,
assigner,
annotation.getValue(SERIALIZABLE_PROXY).resolve(Boolean.class)));
} else {
return MethodDelegationBinder.ParameterBinding.Illegal.INSTANCE;
}
}
/**
* A resolver for creating an instrumentation for a field access.
*/
protected interface FieldResolver {
/**
* Returns {@code true} if the field access can be established.
*
* @return {@code true} if the field access can be established.
*/
boolean isResolved();
/**
* Returns the type of the field access proxy.
*
* @return The type of the field access proxy.
*/
TypeDescription getProxyType();
/**
* Applies this field resolver to a dynamic type.
*
* @param builder The dynamic type builder to use.
* @param fieldDescription The accessed field.
* @param assigner The assigner to use.
* @param methodAccessorFactory The method accessor factory to use.
* @return The builder for creating the field accessor proxy type.
*/
DynamicType.Builder apply(DynamicType.Builder builder,
FieldDescription fieldDescription,
Assigner assigner,
MethodAccessorFactory methodAccessorFactory);
/**
* A factory for creating a field resolver.
*/
interface Factory {
/**
* Creates a field resolver.
*
* @param parameterType The type of the annotated parameter.
* @param fieldDescription The field being proxied.
* @return An appropriate field resolver.
*/
FieldResolver resolve(TypeDescription parameterType, FieldDescription fieldDescription);
/**
* A duplex factory for a type that both sets and gets a field value.
*/
@HashCodeAndEqualsPlugin.Enhance
class Duplex implements Factory {
/**
* The type of the accessor proxy.
*/
private final TypeDescription proxyType;
/**
* The getter method.
*/
private final MethodDescription.InDefinedShape getterMethod;
/**
* The setter method.
*/
private final MethodDescription.InDefinedShape setterMethod;
/**
* Creates a new duplex factory.
*
* @param proxyType The type of the accessor proxy.
* @param getterMethod The getter method.
* @param setterMethod The setter method.
*/
protected Duplex(TypeDescription proxyType,
MethodDescription.InDefinedShape getterMethod,
MethodDescription.InDefinedShape setterMethod) {
this.proxyType = proxyType;
this.getterMethod = getterMethod;
this.setterMethod = setterMethod;
}
/**
* {@inheritDoc}
*/
public FieldResolver resolve(TypeDescription parameterType, FieldDescription fieldDescription) {
if (parameterType.equals(proxyType)) {
return new ForGetterSetterPair(proxyType, getterMethod, setterMethod);
} else {
throw new IllegalStateException("Cannot use @FieldProxy on a non-installed type");
}
}
}
/**
* A simplex factory where field getters and setters both have their own type.
*/
@HashCodeAndEqualsPlugin.Enhance
class Simplex implements Factory {
/**
* The getter method.
*/
private final MethodDescription.InDefinedShape getterMethod;
/**
* The setter method.
*/
private final MethodDescription.InDefinedShape setterMethod;
/**
* Creates a simplex factory.
*
* @param getterMethod The getter method.
* @param setterMethod The setter method.
*/
protected Simplex(MethodDescription.InDefinedShape getterMethod, MethodDescription.InDefinedShape setterMethod) {
this.getterMethod = getterMethod;
this.setterMethod = setterMethod;
}
/**
* {@inheritDoc}
*/
public FieldResolver resolve(TypeDescription parameterType, FieldDescription fieldDescription) {
if (parameterType.equals(getterMethod.getDeclaringType())) {
return new ForGetter(getterMethod);
} else if (parameterType.equals(setterMethod.getDeclaringType())) {
return fieldDescription.isFinal()
? Unresolved.INSTANCE
: new ForSetter(setterMethod);
} else {
throw new IllegalStateException("Cannot use @FieldProxy on a non-installed type");
}
}
}
}
/**
* An unresolved field resolver.
*/
enum Unresolved implements FieldResolver {
/**
* The singleton instance.
*/
INSTANCE;
/**
* {@inheritDoc}
*/
public boolean isResolved() {
return false;
}
/**
* {@inheritDoc}
*/
public TypeDescription getProxyType() {
throw new IllegalStateException("Cannot read type for unresolved field resolver");
}
/**
* {@inheritDoc}
*/
public DynamicType.Builder apply(DynamicType.Builder builder,
FieldDescription fieldDescription,
Assigner assigner,
MethodAccessorFactory methodAccessorFactory) {
throw new IllegalStateException("Cannot apply unresolved field resolver");
}
}
/**
* A field resolver for a getter accessor.
*/
@HashCodeAndEqualsPlugin.Enhance
class ForGetter implements FieldResolver {
/**
* The getter method.
*/
private final MethodDescription.InDefinedShape getterMethod;
/**
* Creates a new getter field resolver.
*
* @param getterMethod The getter method.
*/
protected ForGetter(MethodDescription.InDefinedShape getterMethod) {
this.getterMethod = getterMethod;
}
/**
* {@inheritDoc}
*/
public boolean isResolved() {
return true;
}
/**
* {@inheritDoc}
*/
public TypeDescription getProxyType() {
return getterMethod.getDeclaringType();
}
/**
* {@inheritDoc}
*/
public DynamicType.Builder apply(DynamicType.Builder builder,
FieldDescription fieldDescription,
Assigner assigner,
MethodAccessorFactory methodAccessorFactory) {
return builder.method(definedMethod(is(getterMethod))).intercept(new FieldGetter(fieldDescription, assigner, methodAccessorFactory));
}
}
/**
* A field resolver for a setter accessor.
*/
@HashCodeAndEqualsPlugin.Enhance
class ForSetter implements FieldResolver {
/**
* The setter method.
*/
private final MethodDescription.InDefinedShape setterMethod;
/**
* Creates a new field resolver for a setter accessor.
*
* @param setterMethod The setter method.
*/
protected ForSetter(MethodDescription.InDefinedShape setterMethod) {
this.setterMethod = setterMethod;
}
/**
* {@inheritDoc}
*/
public boolean isResolved() {
return true;
}
/**
* {@inheritDoc}
*/
public TypeDescription getProxyType() {
return setterMethod.getDeclaringType();
}
/**
* {@inheritDoc}
*/
public DynamicType.Builder apply(DynamicType.Builder builder,
FieldDescription fieldDescription,
Assigner assigner,
MethodAccessorFactory methodAccessorFactory) {
return builder.method(is(setterMethod)).intercept(new FieldSetter(fieldDescription, assigner, methodAccessorFactory));
}
}
/**
* A field resolver for an accessor that both gets and sets a field value.
*/
@HashCodeAndEqualsPlugin.Enhance
class ForGetterSetterPair implements FieldResolver {
/**
* The type of the accessor proxy.
*/
private final TypeDescription proxyType;
/**
* The getter method.
*/
private final MethodDescription.InDefinedShape getterMethod;
/**
* The setter method.
*/
private final MethodDescription.InDefinedShape setterMethod;
/**
* Creates a new field resolver for an accessor that both gets and sets a field value.
*
* @param proxyType The type of the accessor proxy.
* @param getterMethod The getter method.
* @param setterMethod The setter method.
*/
protected ForGetterSetterPair(TypeDescription proxyType,
MethodDescription.InDefinedShape getterMethod,
MethodDescription.InDefinedShape setterMethod) {
this.proxyType = proxyType;
this.getterMethod = getterMethod;
this.setterMethod = setterMethod;
}
/**
* {@inheritDoc}
*/
public boolean isResolved() {
return true;
}
/**
* {@inheritDoc}
*/
public TypeDescription getProxyType() {
return proxyType;
}
/**
* {@inheritDoc}
*/
public DynamicType.Builder apply(DynamicType.Builder builder,
FieldDescription fieldDescription,
Assigner assigner,
MethodAccessorFactory methodAccessorFactory) {
return builder
.method(is(getterMethod)).intercept(new FieldGetter(fieldDescription, assigner, methodAccessorFactory))
.method(is(setterMethod)).intercept(fieldDescription.isFinal()
? ExceptionMethod.throwing(UnsupportedOperationException.class, "Cannot set final field " + fieldDescription)
: new FieldSetter(fieldDescription, assigner, methodAccessorFactory));
}
}
}
/**
* Represents an implementation for implementing a proxy type constructor when a static field is accessed.
*/
protected enum StaticFieldConstructor implements Implementation {
/**
* The singleton instance.
*/
INSTANCE;
/**
* A reference of the {@link Object} type default constructor.
*/
private final MethodDescription objectTypeDefaultConstructor;
/**
* Creates the constructor call singleton.
*/
StaticFieldConstructor() {
objectTypeDefaultConstructor = TypeDescription.ForLoadedType.of(Object.class).getDeclaredMethods().filter(isConstructor()).getOnly();
}
/**
* {@inheritDoc}
*/
public InstrumentedType prepare(InstrumentedType instrumentedType) {
return instrumentedType;
}
/**
* {@inheritDoc}
*/
public ByteCodeAppender appender(Target implementationTarget) {
return new ByteCodeAppender.Simple(MethodVariableAccess.loadThis(), MethodInvocation.invoke(objectTypeDefaultConstructor), MethodReturn.VOID);
}
}
/**
* Represents an implementation for implementing a proxy type constructor when a non-static field is accessed.
*/
@HashCodeAndEqualsPlugin.Enhance
protected static class InstanceFieldConstructor implements Implementation {
/**
* The instrumented type from which a field is to be accessed.
*/
private final TypeDescription instrumentedType;
/**
* Creates a new implementation for implementing a field accessor proxy's constructor when accessing
* a non-static field.
*
* @param instrumentedType The instrumented type from which a field is to be accessed.
*/
protected InstanceFieldConstructor(TypeDescription instrumentedType) {
this.instrumentedType = instrumentedType;
}
/**
* {@inheritDoc}
*/
public InstrumentedType prepare(InstrumentedType instrumentedType) {
return instrumentedType.withField(new FieldDescription.Token(AccessorProxy.FIELD_NAME,
Opcodes.ACC_FINAL | Opcodes.ACC_PRIVATE,
this.instrumentedType.asGenericType()));
}
/**
* {@inheritDoc}
*/
public ByteCodeAppender appender(Target implementationTarget) {
return new Appender(implementationTarget);
}
/**
* An appender for implementing an
* {@link FieldProxy.Binder.InstanceFieldConstructor}.
*/
@HashCodeAndEqualsPlugin.Enhance
protected static class Appender implements ByteCodeAppender {
/**
* The field to be set within the constructor.
*/
private final FieldDescription fieldDescription;
/**
* Creates a new appender.
*
* @param implementationTarget The implementation target of the current implementation.
*/
protected Appender(Target implementationTarget) {
fieldDescription = implementationTarget.getInstrumentedType()
.getDeclaredFields()
.filter((named(AccessorProxy.FIELD_NAME)))
.getOnly();
}
/**
* {@inheritDoc}
*/
public Size apply(MethodVisitor methodVisitor,
Context implementationContext,
MethodDescription instrumentedMethod) {
StackManipulation.Size stackSize = new StackManipulation.Compound(
MethodVariableAccess.loadThis(),
MethodInvocation.invoke(StaticFieldConstructor.INSTANCE.objectTypeDefaultConstructor),
MethodVariableAccess.allArgumentsOf(instrumentedMethod.asDefined()).prependThisReference(),
FieldAccess.forField(fieldDescription).write(),
MethodReturn.VOID
).apply(methodVisitor, implementationContext);
return new Size(stackSize.getMaximalSize(), instrumentedMethod.getStackSize());
}
}
}
/**
* Implementation for a getter method.
*/
@HashCodeAndEqualsPlugin.Enhance
protected static class FieldGetter implements Implementation {
/**
* The field that is being accessed.
*/
private final FieldDescription fieldDescription;
/**
* The assigner to use.
*/
private final Assigner assigner;
/**
* The accessed type's method accessor factory.
*/
private final MethodAccessorFactory methodAccessorFactory;
/**
* Creates a new getter implementation.
*
* @param fieldDescription The field that is being accessed.
* @param assigner The assigner to use.
* @param methodAccessorFactory The accessed type's method accessor factory.
*/
protected FieldGetter(FieldDescription fieldDescription,
Assigner assigner,
MethodAccessorFactory methodAccessorFactory) {
this.fieldDescription = fieldDescription;
this.assigner = assigner;
this.methodAccessorFactory = methodAccessorFactory;
}
/**
* {@inheritDoc}
*/
public InstrumentedType prepare(InstrumentedType instrumentedType) {
return instrumentedType;
}
/**
* {@inheritDoc}
*/
public ByteCodeAppender appender(Target implementationTarget) {
return new Appender(implementationTarget);
}
/**
* A byte code appender for a getter method.
*/
@HashCodeAndEqualsPlugin.Enhance(includeSyntheticFields = true)
protected class Appender implements ByteCodeAppender {
/**
* The generated accessor type.
*/
private final TypeDescription typeDescription;
/**
* Creates a new appender for a setter method.
*
* @param implementationTarget The implementation target of the current instrumentation.
*/
protected Appender(Target implementationTarget) {
typeDescription = implementationTarget.getInstrumentedType();
}
/**
* {@inheritDoc}
*/
public Size apply(MethodVisitor methodVisitor,
Context implementationContext,
MethodDescription instrumentedMethod) {
MethodDescription getterMethod = methodAccessorFactory.registerGetterFor(fieldDescription, MethodAccessorFactory.AccessType.DEFAULT);
StackManipulation.Size stackSize = new StackManipulation.Compound(
fieldDescription.isStatic()
? StackManipulation.Trivial.INSTANCE
: new StackManipulation.Compound(
MethodVariableAccess.loadThis(),
FieldAccess.forField(typeDescription.getDeclaredFields().filter((named(AccessorProxy.FIELD_NAME))).getOnly()).read()),
MethodInvocation.invoke(getterMethod),
assigner.assign(getterMethod.getReturnType(), instrumentedMethod.getReturnType(), Assigner.Typing.DYNAMIC),
MethodReturn.of(instrumentedMethod.getReturnType().asErasure())
).apply(methodVisitor, implementationContext);
return new Size(stackSize.getMaximalSize(), instrumentedMethod.getStackSize());
}
}
}
/**
* Implementation for a setter method.
*/
@HashCodeAndEqualsPlugin.Enhance
protected static class FieldSetter implements Implementation {
/**
* The field that is being accessed.
*/
private final FieldDescription fieldDescription;
/**
* The assigner to use.
*/
private final Assigner assigner;
/**
* The accessed type's method accessor factory.
*/
private final MethodAccessorFactory methodAccessorFactory;
/**
* Creates a new setter implementation.
*
* @param fieldDescription The field that is being accessed.
* @param assigner The assigner to use.
* @param methodAccessorFactory The accessed type's method accessor factory.
*/
protected FieldSetter(FieldDescription fieldDescription,
Assigner assigner,
MethodAccessorFactory methodAccessorFactory) {
this.fieldDescription = fieldDescription;
this.assigner = assigner;
this.methodAccessorFactory = methodAccessorFactory;
}
/**
* {@inheritDoc}
*/
public InstrumentedType prepare(InstrumentedType instrumentedType) {
return instrumentedType;
}
/**
* {@inheritDoc}
*/
public ByteCodeAppender appender(Target implementationTarget) {
return new Appender(implementationTarget);
}
/**
* A byte code appender for a setter method.
*/
@HashCodeAndEqualsPlugin.Enhance(includeSyntheticFields = true)
protected class Appender implements ByteCodeAppender {
/**
* The generated accessor type.
*/
private final TypeDescription typeDescription;
/**
* Creates a new appender for a setter method.
*
* @param implementationTarget The implementation target of the current instrumentation.
*/
protected Appender(Target implementationTarget) {
typeDescription = implementationTarget.getInstrumentedType();
}
/**
* {@inheritDoc}
*/
public Size apply(MethodVisitor methodVisitor,
Context implementationContext,
MethodDescription instrumentedMethod) {
TypeDescription.Generic parameterType = instrumentedMethod.getParameters().get(0).getType();
MethodDescription setterMethod = methodAccessorFactory.registerSetterFor(fieldDescription, MethodAccessorFactory.AccessType.DEFAULT);
StackManipulation.Size stackSize = new StackManipulation.Compound(
fieldDescription.isStatic()
? StackManipulation.Trivial.INSTANCE
: new StackManipulation.Compound(
MethodVariableAccess.loadThis(),
FieldAccess.forField(typeDescription.getDeclaredFields()
.filter((named(AccessorProxy.FIELD_NAME))).getOnly()).read()),
MethodVariableAccess.of(parameterType).loadFrom(1),
assigner.assign(parameterType, setterMethod.getParameters().get(0).getType(), Assigner.Typing.DYNAMIC),
MethodInvocation.invoke(setterMethod),
MethodReturn.VOID
).apply(methodVisitor, implementationContext);
return new Size(stackSize.getMaximalSize(), instrumentedMethod.getStackSize());
}
}
}
/**
* A proxy type for accessing a field either by a getter or a setter.
*/
@HashCodeAndEqualsPlugin.Enhance(includeSyntheticFields = true)
protected static class AccessorProxy extends StackManipulation.AbstractBase implements AuxiliaryType {
/**
* The name of the field that stores the accessed instance if any.
*/
protected static final String FIELD_NAME = "instance";
/**
* The field that is being accessed.
*/
private final FieldDescription fieldDescription;
/**
* The type which is accessed.
*/
private final TypeDescription instrumentedType;
/**
* The field resolver to use.
*/
private final FieldResolver fieldResolver;
/**
* The assigner to use.
*/
private final Assigner assigner;
/**
* {@code true} if the generated proxy should be serializable.
*/
private final boolean serializableProxy;
/**
* @param fieldDescription The field that is being accessed.
* @param instrumentedType The type which is accessed.
* @param fieldResolver The field resolver to use.
* @param assigner The assigner to use.
* @param serializableProxy {@code true} if the generated proxy should be serializable.
*/
protected AccessorProxy(FieldDescription fieldDescription,
TypeDescription instrumentedType,
FieldResolver fieldResolver,
Assigner assigner,
boolean serializableProxy) {
this.fieldDescription = fieldDescription;
this.instrumentedType = instrumentedType;
this.fieldResolver = fieldResolver;
this.assigner = assigner;
this.serializableProxy = serializableProxy;
}
/**
* {@inheritDoc}
*/
public String getSuffix() {
return RandomString.hashOf(fieldDescription.hashCode()) + (serializableProxy ? "S" : "0");
}
/**
* {@inheritDoc}
*/
public DynamicType make(String auxiliaryTypeName,
ClassFileVersion classFileVersion,
MethodAccessorFactory methodAccessorFactory) {
return fieldResolver.apply(new ByteBuddy(classFileVersion)
.with(TypeValidation.DISABLED)
.subclass(fieldResolver.getProxyType(), ConstructorStrategy.Default.NO_CONSTRUCTORS)
.name(auxiliaryTypeName)
.modifiers(DEFAULT_TYPE_MODIFIER)
.implement(serializableProxy ? new Class[]{Serializable.class} : new Class[0])
.defineConstructor().withParameters(fieldDescription.isStatic()
? Collections.emptyList()
: Collections.singletonList(instrumentedType))
.intercept(fieldDescription.isStatic()
? StaticFieldConstructor.INSTANCE
: new InstanceFieldConstructor(instrumentedType)), fieldDescription, assigner, methodAccessorFactory).make();
}
/**
* {@inheritDoc}
*/
public Size apply(MethodVisitor methodVisitor, Implementation.Context implementationContext) {
TypeDescription auxiliaryType = implementationContext.register(this);
return new Compound(
TypeCreation.of(auxiliaryType),
Duplication.SINGLE,
fieldDescription.isStatic()
? Trivial.INSTANCE
: MethodVariableAccess.loadThis(),
MethodInvocation.invoke(auxiliaryType.getDeclaredMethods().filter(isConstructor()).getOnly())
).apply(methodVisitor, implementationContext);
}
}
}
}