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/*
* Copyright (C) 2009-2020 The Project Lombok Authors.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package lombok;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Generates implementations for the {@code equals} and {@code hashCode} methods inherited by all objects, based on relevant fields.
*
* Complete documentation is found at the project lombok features page for @EqualsAndHashCode.
*/
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.SOURCE)
public @interface EqualsAndHashCode {
/**
* Any fields listed here will not be taken into account in the generated {@code equals} and {@code hashCode} implementations.
* Mutually exclusive with {@link #of()}.
*
* Will soon be marked {@code @Deprecated}; use the {@code @EqualsAndHashCode.Exclude} annotation instead.
*
* @return A list of fields to exclude.
*/
String[] exclude() default {};
/**
* If present, explicitly lists the fields that are to be used for identity.
* Normally, all non-static, non-transient fields are used for identity.
*
* Mutually exclusive with {@link #exclude()}.
*
* Will soon be marked {@code @Deprecated}; use the {@code @EqualsAndHashCode.Include} annotation together with {@code @EqualsAndHashCode(onlyExplicitlyIncluded = true)}.
*
* @return A list of fields to use (default: all of them).
*/
String[] of() default {};
/**
* Call on the superclass's implementations of {@code equals} and {@code hashCode} before calculating for the fields in this class.
* default: false
*
* @return Whether to call the superclass's {@code equals} implementation as part of the generated equals algorithm.
*/
boolean callSuper() default false;
/**
* Normally, if getters are available, those are called. To suppress this and let the generated code use the fields directly, set this to {@code true}.
* default: false
*
* @return If {@code true}, always use direct field access instead of calling the getter method.
*/
boolean doNotUseGetters() default false;
/**
* Determines how the result of the {@code hashCode} method will be cached.
* default: {@link CacheStrategy#NEVER}
*
* @return The {@code hashCode} cache strategy to be used.
*/
CacheStrategy cacheStrategy() default CacheStrategy.NEVER;
/**
* Any annotations listed here are put on the generated parameter of {@code equals} and {@code canEqual}.
* This is useful to add for example a {@code Nullable} annotation.
* The syntax for this feature depends on JDK version (nothing we can do about that; it's to work around javac bugs).
* up to JDK7:
* {@code @EqualsAndHashCode(onParam=@__({@AnnotationsGoHere}))}
* from JDK8:
* {@code @EqualsAndHashCode(onParam_={@AnnotationsGohere})} // note the underscore after {@code onParam}.
*
* @return List of annotations to apply to the generated parameter in the {@code equals()} method.
*/
AnyAnnotation[] onParam() default {};
/**
* Placeholder annotation to enable the placement of annotations on the generated code.
* @deprecated Don't use this annotation, ever - Read the documentation.
*/
@Deprecated
@Retention(RetentionPolicy.SOURCE)
@Target({})
@interface AnyAnnotation {}
/**
* Only include fields and methods explicitly marked with {@code @EqualsAndHashCode.Include}.
* Normally, all (non-static, non-transient) fields are included by default.
*
* @return If {@code true}, don't include non-static non-transient fields automatically (default: {@code false}).
*/
boolean onlyExplicitlyIncluded() default false;
/**
* If present, do not include this field in the generated {@code equals} and {@code hashCode} methods.
*/
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.SOURCE)
public @interface Exclude {}
/**
* Configure the behaviour of how this member is treated in the {@code equals} and {@code hashCode} implementation; if on a method, include the method's return value as part of calculating hashCode/equality.
*/
@Target({ElementType.FIELD, ElementType.METHOD})
@Retention(RetentionPolicy.SOURCE)
public @interface Include {
/**
* Defaults to the method name of the annotated member.
* If on a method and the name equals the name of a default-included field, this member takes its place.
*
* @return If present, this method serves as replacement for the named field.
*/
String replaces() default "";
/**
* Higher ranks are considered first. Members of the same rank are considered in the order they appear in the source file.
*
* If not explicitly set, the {@code default} rank for primitives is 1000, and for primitive wrappers 800.
*
* @return ordering within the generating {@code equals} and {@code hashCode} methods; higher numbers are considered first.
*/
int rank() default 0;
}
public enum CacheStrategy {
/**
* Never cache. Perform the calculation every time the method is called.
*/
NEVER,
/**
* Cache the result of the first invocation of {@code hashCode} and use it for subsequent invocations.
* This can improve performance if all fields used for calculating the {@code hashCode} are immutable
* and thus every invocation of {@code hashCode} will always return the same value.
* Do not use this if there's any chance that different invocations of {@code hashCode}
* might return different values.
*/
LAZY
}
}