Class EqualsMethod

java.lang.Object

net.bytebuddy.implementation.EqualsMethod

All Implemented Interfaces:

InstrumentedType.Prepareable, Implementation

@Enhance
public class EqualsMethod
extends Object
implements Implementation

An implementation of Object.equals(Object) that takes a class's declared fields into consideration. Equality is resolved by comparing two instances of the same or a compatible class field by field where reference fields must either both be null or where the field value of the instance upon which the method is invoked returns true upon calling the value's equals method. For arrays, the corresponding utilities of Arrays are used.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	EqualsMethod.Appender	A byte code appender to implement the EqualsMethod.
protected static class	EqualsMethod.CompoundComparator	A compound comparator that compares the values of multiple fields.
protected static class	EqualsMethod.ConditionalReturn	A conditional return aborts the equality computation if a given condition was reached.
protected static enum	EqualsMethod.NaturalOrderComparator	A comparator that retains the natural order.
protected static interface	EqualsMethod.NullValueGuard	Guards a field value against a potential null value.
protected static enum	EqualsMethod.SuperClassCheck	Checks the equality contract against the super class.
protected static enum	EqualsMethod.TypeCompatibilityCheck	Checks the overall type of the provided argument.
protected static enum	EqualsMethod.TypePropertyComparator	A comparator that sorts fields by a type property.
protected static enum	EqualsMethod.ValueComparator	A value comparator is responsible to compare to values of a given type.

Nested classes/interfaces inherited from interface Implementation

Implementation.Composable, Implementation.Compound, Implementation.Context, Implementation.Simple, Implementation.SpecialMethodInvocation, Implementation.Target

Nested classes/interfaces inherited from interface InstrumentedType.Prepareable

InstrumentedType.Prepareable.NoOp

Field Summary

Fields

Modifier and Type	Field	Description
private final Comparator<? super FieldDescription.InDefinedShape>	comparator	The comparator to apply for ordering fields.
private static final MethodDescription.InDefinedShape	EQUALS	The Object.equals(Object) method.
private final ElementMatcher.Junction<? super FieldDescription.InDefinedShape>	identity	A matcher to determine that a field should be considered by its identity.
private final ElementMatcher.Junction<? super FieldDescription.InDefinedShape>	ignored	A matcher to filter fields that should not be used for a equality resolution.
private final ElementMatcher.Junction<? super FieldDescription.InDefinedShape>	nonNullable	A matcher to determine fields of a reference type that cannot be null.
private final EqualsMethod.SuperClassCheck	superClassCheck	The baseline equality to check.
private final EqualsMethod.TypeCompatibilityCheck	typeCompatibilityCheck	The instance type compatibility check.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	EqualsMethod(EqualsMethod.SuperClassCheck superClassCheck)	Creates a new equals method implementation.
private	EqualsMethod(EqualsMethod.SuperClassCheck superClassCheck, EqualsMethod.TypeCompatibilityCheck typeCompatibilityCheck, ElementMatcher.Junction<? super FieldDescription.InDefinedShape> ignored, ElementMatcher.Junction<? super FieldDescription.InDefinedShape> nonNullable, ElementMatcher.Junction<? super FieldDescription.InDefinedShape> identity, Comparator<? super FieldDescription.InDefinedShape> comparator)	Creates a new equals method implementation.

Method Summary

Modifier and Type	Method	Description
ByteCodeAppender	appender(Implementation.Target implementationTarget)	Creates a byte code appender that determines the implementation of the instrumented type's methods.
static EqualsMethod	isolated()	Creates an equals method implementation that does not invoke the super class's Object.equals(Object) method.
InstrumentedType	prepare(InstrumentedType instrumentedType)	Prepares a given instrumented type.
static EqualsMethod	requiringSuperClassEquality()	Creates an equals implementation that invokes the super class's Object.equals(Object) method first.
EqualsMethod	withEnumerationTypedFieldsFirst()	Returns a new version of this equals method that compares fields with enumeration types prior to fields with non-enumeration types.
EqualsMethod	withFieldOrder(Comparator<? super FieldDescription.InDefinedShape> comparator)	Applies the supplied comparator to determine an order for fields for being compared.
EqualsMethod	withIdentityFields(ElementMatcher<? super FieldDescription.InDefinedShape> identity)	Returns a new version of this equals method implementation that considers the matched fields by their identity.
EqualsMethod	withIgnoredFields(ElementMatcher<? super FieldDescription.InDefinedShape> ignored)	Returns a new version of this equals method implementation that ignores the specified fields additionally to any previously specified fields.
EqualsMethod	withNonNullableFields(ElementMatcher<? super FieldDescription.InDefinedShape> nonNullable)	Returns a new version of this equals method implementation that does not apply a null value check for the specified fields if they have a reference type additionally to any previously specified fields.
EqualsMethod	withPrimitiveTypedFieldsFirst()	Returns a new version of this equals method that compares fields with primitive types prior to fields with non-primitive types.
EqualsMethod	withPrimitiveWrapperTypedFieldsFirst()	Returns a new version of this equals method that compares fields with primitive wrapper types prior to fields with non-primitive wrapper types.
EqualsMethod	withStringTypedFieldsFirst()	Returns a new version of this equals method that compares fields with String types prior to fields with non-String types.
EqualsMethod	withSubclassEquality()	Returns a new version of this equals method implementation that permits subclasses of the instrumented type to be equal to instances of the instrumented type instead of requiring an exact match.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

EQUALS

private static final MethodDescription.InDefinedShape EQUALS

The Object.equals(Object) method.

superClassCheck

private final EqualsMethod.SuperClassCheck superClassCheck

The baseline equality to check.

typeCompatibilityCheck

private final EqualsMethod.TypeCompatibilityCheck typeCompatibilityCheck

The instance type compatibility check.

ignored

private final ElementMatcher.Junction<? super FieldDescription.InDefinedShape> ignored

A matcher to filter fields that should not be used for a equality resolution.

nonNullable

private final ElementMatcher.Junction<? super FieldDescription.InDefinedShape> nonNullable

A matcher to determine fields of a reference type that cannot be null.

identity

private final ElementMatcher.Junction<? super FieldDescription.InDefinedShape> identity

A matcher to determine that a field should be considered by its identity.

comparator

private final Comparator<? super FieldDescription.InDefinedShape> comparator

The comparator to apply for ordering fields.

Constructor Details

EqualsMethod

protected EqualsMethod(EqualsMethod.SuperClassCheck superClassCheck)

Creates a new equals method implementation.

Parameters:

superClassCheck - The baseline equality to check.

EqualsMethod

private EqualsMethod(EqualsMethod.SuperClassCheck superClassCheck,
 EqualsMethod.TypeCompatibilityCheck typeCompatibilityCheck,
 ElementMatcher.Junction<? super FieldDescription.InDefinedShape> ignored,
 ElementMatcher.Junction<? super FieldDescription.InDefinedShape> nonNullable,
 ElementMatcher.Junction<? super FieldDescription.InDefinedShape> identity,
 Comparator<? super FieldDescription.InDefinedShape> comparator)

Creates a new equals method implementation.

Parameters:

superClassCheck - The baseline equality to check.

typeCompatibilityCheck - The instance type compatibility check.

ignored - A matcher to filter fields that should not be used for a equality resolution.

nonNullable - A matcher to determine fields of a reference type that cannot be null.

identity - A matcher to determine that a field should be considered by its identity.

comparator - The comparator to apply for ordering fields.

Method Details

requiringSuperClassEquality

public static EqualsMethod requiringSuperClassEquality()

Creates an equals implementation that invokes the super class's Object.equals(Object) method first.

Returns:

An equals implementation that invokes the super class's Object.equals(Object) method first.

isolated

public static EqualsMethod isolated()

Creates an equals method implementation that does not invoke the super class's Object.equals(Object) method.

Returns:

An equals method implementation that does not invoke the super class's Object.equals(Object) method.

withIgnoredFields

public EqualsMethod withIgnoredFields(ElementMatcher<? super FieldDescription.InDefinedShape> ignored)

Returns a new version of this equals method implementation that ignores the specified fields additionally to any previously specified fields.

Parameters:

ignored - A matcher to specify any fields that should be ignored.

Returns:

A new version of this equals method implementation that also ignores any fields matched by the provided matcher.

withNonNullableFields

public EqualsMethod withNonNullableFields(ElementMatcher<? super FieldDescription.InDefinedShape> nonNullable)

Returns a new version of this equals method implementation that does not apply a null value check for the specified fields if they have a reference type additionally to any previously specified fields.

Parameters:

nonNullable - A matcher to specify any fields that should not be guarded against null values.

Returns:

A new version of this equals method implementation that also does not apply null value checks to any fields matched by the provided matcher.

withIdentityFields

public EqualsMethod withIdentityFields(ElementMatcher<? super FieldDescription.InDefinedShape> identity)

Returns a new version of this equals method implementation that considers the matched fields by their identity.

Parameters:

identity - A matcher to determine that a field should be considered by its identity.

Returns:

A new version of this equals method implementation that also considers the matched fields by their identity.

withPrimitiveTypedFieldsFirst

public EqualsMethod withPrimitiveTypedFieldsFirst()

Returns a new version of this equals method that compares fields with primitive types prior to fields with non-primitive types.

Returns:

A new version of this equals method that compares primitive-typed fields before fields with non-primitive-typed fields.

withEnumerationTypedFieldsFirst

public EqualsMethod withEnumerationTypedFieldsFirst()

Returns a new version of this equals method that compares fields with enumeration types prior to fields with non-enumeration types.

Returns:

A new version of this equals method that compares enumeration-typed fields before fields with non-enumeration-typed fields.

withPrimitiveWrapperTypedFieldsFirst

public EqualsMethod withPrimitiveWrapperTypedFieldsFirst()

Returns a new version of this equals method that compares fields with primitive wrapper types prior to fields with non-primitive wrapper types.

Returns:

A new version of this equals method that compares primitive wrapper-typed fields before fields with non-primitive wrapper-typed fields.

withStringTypedFieldsFirst

public EqualsMethod withStringTypedFieldsFirst()

Returns a new version of this equals method that compares fields with String types prior to fields with non-String types.

Returns:

A new version of this equals method that compares String-typed fields before fields with non-String-typed fields.

withFieldOrder

public EqualsMethod withFieldOrder(Comparator<? super FieldDescription.InDefinedShape> comparator)

Applies the supplied comparator to determine an order for fields for being compared. Fields with the lowest sort order are compared first. Any previously defined comparators are applied prior to the supplied comparator.

Parameters:

comparator - The comparator to apply.

Returns:

A new version of this equals method that sorts fields in their application order using the supplied comparator.

withSubclassEquality

public EqualsMethod withSubclassEquality()

Returns a new version of this equals method implementation that permits subclasses of the instrumented type to be equal to instances of the instrumented type instead of requiring an exact match.

Returns:

A new version of this equals method implementation that permits subclasses of the instrumented type to be equal to instances of the instrumented type instead of requiring an exact match.

prepare

public InstrumentedType prepare(InstrumentedType instrumentedType)

Prepares a given instrumented type.

Specified by:

prepare in interface InstrumentedType.Prepareable

Parameters:

instrumentedType - The instrumented type in its current form.

Returns:

The prepared instrumented type.

appender

public ByteCodeAppender appender(Implementation.Target implementationTarget)

Creates a byte code appender that determines the implementation of the instrumented type's methods.

Specified by:

appender in interface Implementation

Parameters:

implementationTarget - The target of the current implementation.

Returns:

A byte code appender for implementing methods delegated to this implementation. This byte code appender is also responsible for handling methods that were added by this implementation on the call to InstrumentedType.Prepareable.prepare(InstrumentedType).