net.bytebuddy.build.ToStringPlugin Maven / Gradle / Ivy
/*
* 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.build;
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.type.TypeDescription;
import net.bytebuddy.dynamic.ClassFileLocator;
import net.bytebuddy.dynamic.DynamicType;
import net.bytebuddy.implementation.ToStringMethod;
import net.bytebuddy.matcher.ElementMatchers;
import net.bytebuddy.utility.nullability.MaybeNull;
import java.lang.annotation.*;
import static net.bytebuddy.matcher.ElementMatchers.*;
/**
* A build tool plugin that adds a {@link Object#toString()} and method to a class if the {@link Enhance} annotation is present and no
* explicit method declaration was added. This plugin does not need to be closed.
*/
@HashCodeAndEqualsPlugin.Enhance
public class ToStringPlugin implements Plugin, Plugin.Factory {
/**
* A description of the {@link Enhance#prefix()} method.
*/
private static final MethodDescription.InDefinedShape ENHANCE_PREFIX;
/**
* A description of the {@link Enhance#includeSyntheticFields()} method.
*/
private static final MethodDescription.InDefinedShape ENHANCE_INCLUDE_SYNTHETIC_FIELDS;
/*
* Resolves annotation properties.
*/
static {
MethodList enhanceMethods = TypeDescription.ForLoadedType.of(Enhance.class).getDeclaredMethods();
ENHANCE_PREFIX = enhanceMethods.filter(named("prefix")).getOnly();
ENHANCE_INCLUDE_SYNTHETIC_FIELDS = enhanceMethods.filter(named("includeSyntheticFields")).getOnly();
}
/**
* {@inheritDoc}
*/
public Plugin make() {
return this;
}
/**
* {@inheritDoc}
*/
public boolean matches(@MaybeNull TypeDescription target) {
return target != null && target.getDeclaredAnnotations().isAnnotationPresent(Enhance.class);
}
/**
* {@inheritDoc}
*/
public DynamicType.Builder apply(DynamicType.Builder builder, TypeDescription typeDescription, ClassFileLocator classFileLocator) {
AnnotationDescription.Loadable enhance = typeDescription.getDeclaredAnnotations().ofType(Enhance.class);
if (typeDescription.getDeclaredMethods().filter(isToString()).isEmpty()) {
builder = builder.method(isToString()).intercept(ToStringMethod.prefixedBy(enhance.getValue(ENHANCE_PREFIX)
.load(Enhance.class.getClassLoader())
.resolve(Enhance.Prefix.class)
.getPrefixResolver())
.withIgnoredFields(enhance.getValue(ENHANCE_INCLUDE_SYNTHETIC_FIELDS).resolve(Boolean.class)
? ElementMatchers.none()
: ElementMatchers.isSynthetic())
.withIgnoredFields(isAnnotatedWith(Exclude.class)));
}
return builder;
}
/**
* {@inheritDoc}
*/
public void close() {
/* do nothing */
}
/**
* Instructs the {@link ToStringPlugin} to generate a {@link Object#toString()} method for the annotated class unless this method
* is already declared explicitly.
*/
@Documented
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface Enhance {
/**
* Determines the prefix to be used for the string representation prior to adding field values.
*
* @return The prefix to use.
*/
Prefix prefix() default Prefix.SIMPLE;
/**
* Determines if synthetic fields should be included in the string representation.
*
* @return {@code true} if synthetic fields should be included.
*/
boolean includeSyntheticFields() default false;
/**
* A strategy for defining a prefix.
*/
enum Prefix {
/**
* Determines the use of a fully qualified class name as a prefix.
*/
FULLY_QUALIFIED(ToStringMethod.PrefixResolver.Default.FULLY_QUALIFIED_CLASS_NAME),
/**
* Determines the use of the canonical class name as a prefix.
*/
CANONICAL(ToStringMethod.PrefixResolver.Default.CANONICAL_CLASS_NAME),
/**
* Determines the use of the simple class name as a prefix.
*/
SIMPLE(ToStringMethod.PrefixResolver.Default.SIMPLE_CLASS_NAME);
/**
* The prefix resolver to use.
*/
private final ToStringMethod.PrefixResolver.Default prefixResolver;
/**
* Creates a new prefix.
*
* @param prefixResolver The prefix resolver to use.
*/
Prefix(ToStringMethod.PrefixResolver.Default prefixResolver) {
this.prefixResolver = prefixResolver;
}
/**
* Returns the prefix resolver to use.
*
* @return The prefix resolver to use.
*/
protected ToStringMethod.PrefixResolver.Default getPrefixResolver() {
return prefixResolver;
}
}
}
/**
* Determines that the annotated field is excluded from a string representation of the {@link ToStringPlugin}.
*/
@Documented
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Exclude {
/* does not declare any properties */
}
}