/*
 * Copyright 2014 - 2020 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.description.annotation.AnnotationDescription;
import net.bytebuddy.description.method.MethodDescription;
import net.bytebuddy.description.method.ParameterDescription;
import net.bytebuddy.description.type.TypeDescription;
import net.bytebuddy.implementation.Implementation;
import net.bytebuddy.implementation.bind.MethodDelegationBinder;
import net.bytebuddy.implementation.bytecode.StackManipulation;
import net.bytebuddy.implementation.bytecode.assign.Assigner;
import net.bytebuddy.implementation.bytecode.constant.DefaultValue;
import net.bytebuddy.implementation.bytecode.constant.NullConstant;

import java.lang.annotation.*;

A stub value represents the (boxed) default value of the intercepted method's return type. This value can only be assigned to a Object parameter. This annotation is useful to conditionally return a default value from a method when using an Object return type in combination with the RuntimeType annotation. The value is either representing null if a method returns a reference type or void or a boxed primitive of the return type representing the numeric value 0.
See Also:
/** * A stub value represents the (boxed) default value of the intercepted method's return type. This value can * only be assigned to a {@link java.lang.Object} parameter. This annotation is useful to conditionally return a * default value from a method when using an {@link java.lang.Object} return type in combination with the * {@link net.bytebuddy.implementation.bind.annotation.RuntimeType} annotation. The value is either representing * {@code null} if a method returns a reference type or {@code void} or a boxed primitive of the return type * representing the numeric value {@code 0}. * * @see net.bytebuddy.implementation.MethodDelegation * @see net.bytebuddy.implementation.bind.annotation.TargetMethodAnnotationDrivenBinder */
@Documented @Retention(RetentionPolicy.RUNTIME) @Target({ElementType.PARAMETER}) public @interface StubValue {
Binds the StubValue annotation.
/** * Binds the {@link net.bytebuddy.implementation.bind.annotation.StubValue} annotation. */
enum Binder implements TargetMethodAnnotationDrivenBinder.ParameterBinder<StubValue> {
The singleton instance.
/** * The singleton instance. */
INSTANCE;
{@inheritDoc}
/** * {@inheritDoc} */
public Class<StubValue> getHandledType() { return StubValue.class; }
{@inheritDoc}
/** * {@inheritDoc} */
public MethodDelegationBinder.ParameterBinding<?> bind(AnnotationDescription.Loadable<StubValue> annotation, MethodDescription source, ParameterDescription target, Implementation.Target implementationTarget, Assigner assigner, Assigner.Typing typing) { if (!target.getType().represents(Object.class)) { throw new IllegalStateException(target + " uses StubValue annotation on non-Object type"); } return new MethodDelegationBinder.ParameterBinding.Anonymous(source.getReturnType().represents(void.class) ? NullConstant.INSTANCE : new StackManipulation.Compound(DefaultValue.of(source.getReturnType().asErasure()), assigner.assign(source.getReturnType(), TypeDescription.Generic.OBJECT, typing))); } } }