package net.bytebuddy.implementation.bind.annotation;
import lombok.EqualsAndHashCode;
import net.bytebuddy.ByteBuddy;
import net.bytebuddy.ClassFileVersion;
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.subclass.ConstructorStrategy;
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.collection.ArrayAccess;
import net.bytebuddy.implementation.bytecode.constant.IntegerConstant;
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.matcher.ElementMatchers;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import java.io.Serializable;
import java.lang.annotation.*;
import java.util.Collections;
import static net.bytebuddy.matcher.ElementMatchers.*;
/**
* This annotation instructs Byte Buddy to inject a proxy class that calls a method's super method with
* explicit arguments. For this, the {@link Morph.Binder}
* needs to be installed for an interface type that takes an argument of the array type {@link java.lang.Object} and
* returns a non-array type of {@link java.lang.Object}. This is an alternative to using the
* {@link net.bytebuddy.implementation.bind.annotation.SuperCall} or
* {@link net.bytebuddy.implementation.bind.annotation.DefaultCall} annotations which call a super
* method using the same arguments as the intercepted method was invoked with.
*
* @see net.bytebuddy.implementation.MethodDelegation
* @see net.bytebuddy.implementation.bind.annotation.TargetMethodAnnotationDrivenBinder
*/
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.PARAMETER)
public @interface Morph {
/**
* Determines if the injected proxy for this parameter should be serializable.
*
* @return {@code true} if the proxy should be serializable.
*/
boolean serializableProxy() default false;
/**
* Determines if the proxy should attempt to invoke a default method. If the default method is ambiguous,
* use the {@link Morph#defaultTarget()} property instead which allows to determine an explicit interface
* on which the default method should be invoked on. If this other method is used, this property is ignored.
*
* @return {@code true} if a default method should be ignored.
*/
boolean defaultMethod() default false;
/**
* The type on which a default method should be invoked. When this property is not set and the
* {@link Morph#defaultMethod()} property is set to {@code false}, a normal super method invocation is attempted.
*
* @return The target interface of a default method call.
*/
Class<?> defaultTarget() default void.class;
/**
* A binder for the {@link net.bytebuddy.implementation.bind.annotation.Morph} annotation.
*/
@EqualsAndHashCode
class Binder implements TargetMethodAnnotationDrivenBinder.ParameterBinder<Morph> {
/**
* A reference to the serializable proxy method.
*/
private static final MethodDescription.InDefinedShape SERIALIZABLE_PROXY;
/**
* A reference to the default method method.
*/
private static final MethodDescription.InDefinedShape DEFAULT_METHOD;
/**
* A reference to the default target method.
*/
private static final MethodDescription.InDefinedShape DEFAULT_TARGET;
/*
* Looks up references for all annotation properties of the morph annotation.
*/
static {
MethodList<MethodDescription.InDefinedShape> methodList = new TypeDescription.ForLoadedType(Morph.class).getDeclaredMethods();
SERIALIZABLE_PROXY = methodList.filter(named("serializableProxy")).getOnly();
DEFAULT_METHOD = methodList.filter(named("defaultMethod")).getOnly();
DEFAULT_TARGET = methodList.filter(named("defaultTarget")).getOnly();
}
/**
* The method which is overridden for generating the proxy class.
*/
private final MethodDescription forwardingMethod;
/**
* Creates a new binder.
*
* @param forwardingMethod The method which is overridden for generating the proxy class.
*/
protected Binder(MethodDescription forwardingMethod) {
this.forwardingMethod = forwardingMethod;
}
/**
* Installs a given type for use on a {@link net.bytebuddy.implementation.bind.annotation.Morph}
* annotation. The given type must be an interface without any super interfaces and a single method which
* maps an {@link java.lang.Object} array to a {@link java.lang.Object} type. The use of generics is
* permitted.
*
* @param type The type to install.
* @return A binder for the {@link net.bytebuddy.implementation.bind.annotation.Morph}
* annotation.
*/
public static TargetMethodAnnotationDrivenBinder.ParameterBinder<Morph> install(Class<?> type) {
return install(new TypeDescription.ForLoadedType(type));
}
/**
* Installs a given type for use on a {@link net.bytebuddy.implementation.bind.annotation.Morph}
* annotation. The given type must be an interface without any super interfaces and a single method which
* maps an {@link java.lang.Object} array to a {@link java.lang.Object} type. The use of generics is
* permitted.
*
* @param typeDescription The type to install.
* @return A binder for the {@link net.bytebuddy.implementation.bind.annotation.Morph}
* annotation.
*/
public static TargetMethodAnnotationDrivenBinder.ParameterBinder<Morph> install(TypeDescription typeDescription) {
return new Binder(onlyMethod(typeDescription));
}
/**
* Extracts the only method of a given type and validates to fit the constraints of the morph annotation.
*
* @param typeDescription The type to extract the method from.
* @return The only method after validation.
*/
private static MethodDescription 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 mot public");
}
MethodList<?> methodCandidates = typeDescription.getDeclaredMethods().filter(isAbstract());
if (methodCandidates.size() != 1) {
throw new IllegalArgumentException(typeDescription + " must declare exactly one abstract method");
}
MethodDescription methodDescription = methodCandidates.getOnly();
if (!methodDescription.getReturnType().asErasure().represents(Object.class)) {
throw new IllegalArgumentException(methodDescription + " does not return an Object-type");
} else if (methodDescription.getParameters().size() != 1 || !methodDescription.getParameters().get(0).getType().asErasure().represents(Object[].class)) {
throw new IllegalArgumentException(methodDescription + " does not take a single argument of type Object[]");
}
return methodDescription;
}
@Override
public Class<Morph> getHandledType() {
return Morph.class;
}
@Override
public MethodDelegationBinder.ParameterBinding<?> bind(AnnotationDescription.Loadable<Morph> annotation,
MethodDescription source,
ParameterDescription target,
Implementation.Target implementationTarget,
Assigner assigner,
Assigner.Typing typing) {
if (!target.getType().asErasure().equals(forwardingMethod.getDeclaringType())) {
throw new IllegalStateException("Illegal use of @Morph for " + target + " which was installed for " + forwardingMethod.getDeclaringType());
}
Implementation.SpecialMethodInvocation specialMethodInvocation;
TypeDescription typeDescription = annotation.getValue(DEFAULT_TARGET).resolve(TypeDescription.class);
if (typeDescription.represents(void.class) && !annotation.getValue(DEFAULT_METHOD).resolve(Boolean.class)) {
specialMethodInvocation = implementationTarget.invokeSuper(source.asSignatureToken());
} else {
specialMethodInvocation = (typeDescription.represents(void.class)
? DefaultMethodLocator.Implicit.INSTANCE
: new DefaultMethodLocator.Explicit(typeDescription)).resolve(implementationTarget, source);
}
return specialMethodInvocation.isValid()
? new MethodDelegationBinder.ParameterBinding.Anonymous(new RedirectionProxy(forwardingMethod.getDeclaringType().asErasure(),
implementationTarget.getInstrumentedType(),
specialMethodInvocation,
assigner,
annotation.getValue(SERIALIZABLE_PROXY).resolve(Boolean.class)))
: MethodDelegationBinder.ParameterBinding.Illegal.INSTANCE;
}
/**
* A default method locator is responsible for looking up a default method to a given source method.
*/
protected interface DefaultMethodLocator {
/**
* Locates the correct default method to a given source method.
*
* @param implementationTarget The current implementation target.
* @param source The source method for which a default method should be looked up.
* @return A special method invocation of the default method or an illegal special method invocation,
* if no suitable invocation could be located.
*/
Implementation.SpecialMethodInvocation resolve(Implementation.Target implementationTarget,
MethodDescription source);
/**
* An implicit default method locator that only permits the invocation of a default method if the source
* method itself represents a method that was defined on a default method interface.
*/
enum Implicit implements DefaultMethodLocator {
/**
* The singleton instance.
*/
INSTANCE;
@Override
public Implementation.SpecialMethodInvocation resolve(Implementation.Target implementationTarget, MethodDescription source) {
return implementationTarget.invokeDefault(source.asSignatureToken());
}
}
/**
* An explicit default method locator attempts to look up a default method in the specified interface type.
*/
@EqualsAndHashCode
class Explicit implements DefaultMethodLocator {
/**
* A description of the type on which the default method should be invoked.
*/
private final TypeDescription typeDescription;
/**
* Creates a new explicit default method locator.
*
* @param typeDescription The actual target interface as explicitly defined by
* {@link DefaultCall#targetType()}.
*/
public Explicit(TypeDescription typeDescription) {
this.typeDescription = typeDescription;
}
@Override
public Implementation.SpecialMethodInvocation resolve(Implementation.Target implementationTarget, MethodDescription source) {
if (!typeDescription.isInterface()) {
throw new IllegalStateException(source + " method carries default method call parameter on non-interface type");
}
return implementationTarget.invokeDefault(source.asSignatureToken(), typeDescription);
}
}
}
/**
* A proxy that implements the installed interface in order to allow for a morphed super method invocation.
*/
@EqualsAndHashCode
protected static class RedirectionProxy implements AuxiliaryType, StackManipulation {
/**
* The name of the field that carries an instance for invoking a super method on.
*/
protected static final String FIELD_NAME = "target";
/**
* The interface type that is implemented by the generated proxy.
*/
private final TypeDescription morphingType;
/**
* The type that is instrumented on which the super method is invoked.
*/
private final TypeDescription instrumentedType;
/**
* The special method invocation to be executed by the morphing type via an accessor on the
* instrumented type.
*/
private final Implementation.SpecialMethodInvocation specialMethodInvocation;
/**
* The assigner to use.
*/
private final Assigner assigner;
/**
* Determines if the generated proxy should be {@link java.io.Serializable}.
*/
private final boolean serializableProxy;
/**
* Creates a new redirection proxy.
*
* @param morphingType The interface type that is implemented by the generated proxy.
* @param instrumentedType The type that is instrumented on which the super method is invoked.
* @param specialMethodInvocation The special method invocation to be executed by the morphing type via
* an accessor on the instrumented type.
* @param assigner The assigner to use.
* @param serializableProxy {@code true} if the proxy should be serializable.
*/
protected RedirectionProxy(TypeDescription morphingType,
TypeDescription instrumentedType,
Implementation.SpecialMethodInvocation specialMethodInvocation,
Assigner assigner,
boolean serializableProxy) {
this.morphingType = morphingType;
this.instrumentedType = instrumentedType;
this.specialMethodInvocation = specialMethodInvocation;
this.assigner = assigner;
this.serializableProxy = serializableProxy;
}
@Override
public DynamicType make(String auxiliaryTypeName,
ClassFileVersion classFileVersion,
MethodAccessorFactory methodAccessorFactory) {
return new ByteBuddy(classFileVersion)
.subclass(morphingType, ConstructorStrategy.Default.NO_CONSTRUCTORS)
.name(auxiliaryTypeName)
.modifiers(DEFAULT_TYPE_MODIFIER)
.implement(serializableProxy ? new Class<?>[]{Serializable.class} : new Class<?>[0])
.defineConstructor().withParameters(specialMethodInvocation.getMethodDescription().isStatic()
? Collections.<TypeDescription>emptyList()
: Collections.singletonList(instrumentedType))
.intercept(specialMethodInvocation.getMethodDescription().isStatic()
? StaticFieldConstructor.INSTANCE
: new InstanceFieldConstructor(instrumentedType))
.method(ElementMatchers.<MethodDescription>isAbstract().and(isDeclaredBy(morphingType)))
.intercept(new MethodCall(methodAccessorFactory.registerAccessorFor(specialMethodInvocation, MethodAccessorFactory.AccessType.DEFAULT), assigner))
.make();
}
@Override
public boolean isValid() {
return true;
}
@Override
public Size apply(MethodVisitor methodVisitor, Implementation.Context implementationContext) {
TypeDescription forwardingType = implementationContext.register(this);
return new Compound(
TypeCreation.of(forwardingType),
Duplication.SINGLE,
specialMethodInvocation.getMethodDescription().isStatic()
? Trivial.INSTANCE
: MethodVariableAccess.loadThis(),
MethodInvocation.invoke(forwardingType.getDeclaredMethods().filter(isConstructor()).getOnly())
).apply(methodVisitor, implementationContext);
}
/**
* Creates an instance of the proxy when instrumenting a static method.
*/
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.OBJECT.getDeclaredMethods()
.filter(isConstructor())
.getOnly();
}
@Override
public InstrumentedType prepare(InstrumentedType instrumentedType) {
return instrumentedType;
}
@Override
public ByteCodeAppender appender(Target implementationTarget) {
return new ByteCodeAppender.Simple(MethodVariableAccess.loadThis(), MethodInvocation.invoke(objectTypeDefaultConstructor), MethodReturn.VOID);
}
}
/**
* Creates an instance of the proxy when instrumenting an instance method.
*/
@EqualsAndHashCode
protected static class InstanceFieldConstructor implements Implementation {
/**
* The instrumented type.
*/
private final TypeDescription instrumentedType;
/**
* Creates a new instance field constructor implementation.
*
* @param instrumentedType The instrumented type.
*/
protected InstanceFieldConstructor(TypeDescription instrumentedType) {
this.instrumentedType = instrumentedType;
}
@Override
public InstrumentedType prepare(InstrumentedType instrumentedType) {
return instrumentedType.withField(new FieldDescription.Token(RedirectionProxy.FIELD_NAME,
Opcodes.ACC_FINAL | Opcodes.ACC_PRIVATE,
this.instrumentedType.asGenericType()));
}
@Override
public ByteCodeAppender appender(Target implementationTarget) {
return new Appender(implementationTarget);
}
/**
* The byte code appender that implements the constructor.
*/
@EqualsAndHashCode
protected static class Appender implements ByteCodeAppender {
/**
* The field that carries the instance on which the super method is invoked.
*/
private final FieldDescription fieldDescription;
/**
* Creates a new appender.
*
* @param implementationTarget The current implementation target.
*/
protected Appender(Target implementationTarget) {
fieldDescription = implementationTarget.getInstrumentedType()
.getDeclaredFields()
.filter((named(RedirectionProxy.FIELD_NAME)))
.getOnly();
}
@Override
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).prependThisReference(),
FieldAccess.forField(fieldDescription).write(),
MethodReturn.VOID
).apply(methodVisitor, implementationContext);
return new Size(stackSize.getMaximalSize(), instrumentedMethod.getStackSize());
}
}
}
/**
* Implements a the method call of the morphing method.
*/
@EqualsAndHashCode
protected static class MethodCall implements Implementation {
/**
* The accessor method to invoke from the proxy's method.
*/
private final MethodDescription accessorMethod;
/**
* The assigner to be used.
*/
private final Assigner assigner;
/**
* Creates a new method call implementation for a proxy method.
*
* @param accessorMethod The accessor method to invoke from the proxy's method.
* @param assigner The assigner to be used.
*/
protected MethodCall(MethodDescription accessorMethod, Assigner assigner) {
this.accessorMethod = accessorMethod;
this.assigner = assigner;
}
@Override
public InstrumentedType prepare(InstrumentedType instrumentedType) {
return instrumentedType;
}
@Override
public ByteCodeAppender appender(Target implementationTarget) {
return new Appender(implementationTarget);
}
/**
* The byte code appender to implement the method.
*/
protected class Appender implements ByteCodeAppender {
/**
* The proxy type.
*/
private final TypeDescription typeDescription;
/**
* Creates a new appender.
*
* @param implementationTarget The current implementation target.
*/
protected Appender(Target implementationTarget) {
typeDescription = implementationTarget.getInstrumentedType();
}
@Override
public Size apply(MethodVisitor methodVisitor,
Context implementationContext,
MethodDescription instrumentedMethod) {
StackManipulation arrayReference = MethodVariableAccess.REFERENCE.loadFrom(1);
StackManipulation[] parameterLoading = new StackManipulation[accessorMethod.getParameters().size()];
int index = 0;
for (TypeDescription.Generic parameterType : accessorMethod.getParameters().asTypeList()) {
parameterLoading[index] = new StackManipulation.Compound(arrayReference,
IntegerConstant.forValue(index),
ArrayAccess.REFERENCE.load(),
assigner.assign(TypeDescription.Generic.OBJECT, parameterType, Assigner.Typing.DYNAMIC));
index++;
}
StackManipulation.Size stackSize = new StackManipulation.Compound(
accessorMethod.isStatic()
? Trivial.INSTANCE
: new StackManipulation.Compound(
MethodVariableAccess.loadThis(),
FieldAccess.forField(typeDescription.getDeclaredFields()
.filter((named(RedirectionProxy.FIELD_NAME)))
.getOnly()).read()),
new StackManipulation.Compound(parameterLoading),
MethodInvocation.invoke(accessorMethod),
assigner.assign(accessorMethod.getReturnType(), instrumentedMethod.getReturnType(), Assigner.Typing.DYNAMIC),
MethodReturn.REFERENCE
).apply(methodVisitor, implementationContext);
return new Size(stackSize.getMaximalSize(), instrumentedMethod.getStackSize());
}
/**
* Returns the outer instance.
*
* @return The outer instance.
*/
private MethodCall getMethodCall() {
return MethodCall.this;
}
@Override // HE: Remove when Lombok support for getOuter is added.
public boolean equals(Object other) {
return this == other || !(other == null || getClass() != other.getClass())
&& MethodCall.this.equals(((Appender) other).getMethodCall())
&& typeDescription.equals(((Appender) other).typeDescription);
}
@Override // HE: Remove when Lombok support for getOuter is added.
public int hashCode() {
return typeDescription.hashCode() + 31 * MethodCall.this.hashCode();
}
}
}
}
}
}