de.alpharogroup.evaluate.object.checkers

Class EqualsCheck

java.lang.Object

de.alpharogroup.evaluate.object.checkers.EqualsCheck

public final class EqualsCheck
extends Object

The class EqualsCheck provides algorithms for check the equals contract of an given object.

Constructor Summary

Constructors

Constructor and Description
EqualsCheck()

Method Summary

Modifier and Type	Method and Description
static <T> Optional<ContractViolation>	consistency(T object, T anotherObject) Checks the contract condition for consistency of the given objects, that means according to Object.equals(Object) that this method should evaluate the following contract condition: It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
static <T> Optional<ContractViolation>	consistency(T object, T anotherObject, int iterations) Checks the contract condition for consistency of the given objects, that means according to Object.equals(Object) that this method should evaluate the following contract condition: It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
static <T> Optional<ContractViolation>	nonNull(T object) Checks the contract condition for non-null condition is given of the given object, that means according to Object.equals(Object) that this method should evaluate the following contract condition: For any non-null reference value x, x.equals(null) should return false.
static <T> Optional<ContractViolation>	reflexivity(T object) Checks the contract condition for reflexivity of the given object, that means according to Object.equals(Object) that this method should evaluate the following contract condition: It is reflexive: for any non-null reference value x, x.equals(x) should return true.
static <T> Optional<ContractViolation>	reflexivityAndNonNull(T object) Checks the contract conditions for reflexivity and non null, that means according to Object.equals(Object) that this method should evaluate the following contract condition: It is reflexive: for any non-null reference value x, x.equals(x) should return true.
static <T> Optional<ContractViolation>	reflexivityNonNullSymmetricAndConsistency(T object, T otherObject) Checks the contract conditions for reflexivity, non null, symmetric and consistency of the given objects, that means according to Object.equals(Object) that this method should evaluate the following contract condition: It is reflexive: for any non-null reference value x, x.equals(x) should return true.
static <T> Optional<ContractViolation>	reflexivityNonNullSymmetricConsistencyAndTransitivity(T object, T otherObject, T anotherObject) Checks the contract conditions for reflexivity, non null, symmetric, consistency and transitivity of the given objects, that means according to Object.equals(Object) that this method should evaluate the following contract condition: It is reflexive: for any non-null reference value x, x.equals(x) should return true.
static <T> Optional<ContractViolation>	symmetric(T object, T anotherObject) Checks the contract condition for symmetric of the given objects, that means according to Object.equals(Object) that this method should evaluate the following contract condition: It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
static <T> Optional<ContractViolation>	symmetricAndConsistency(T object, T anotherObject) Checks the contract conditions for symmetric and consistency of the given objects, that means according to Object.equals(Object) that this method should evaluate the following contract condition: It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
static <T> Optional<ContractViolation>	transitivity(T a, T b, T c) Checks the contract condition for transitivity of the given objects, that means according to Object.equals(Object) that this method should evaluate the following contract condition: It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.

Methods inherited from class java.lang.Object

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

Constructor Detail

EqualsCheck

public EqualsCheck()

Method Detail

reflexivity

public static <T> Optional<ContractViolation> reflexivity(T object)

Checks the contract condition for reflexivity of the given object, that means according to Object.equals(Object) that this method should evaluate the following contract condition:

• It is reflexive: for any non-null reference value x, x.equals(x) should return true.

Note: The upper list entry is taken from the javadoc from Object.equals(Object)

Type Parameters:

T - the generic type

Parameters:

object - the object

Returns:

an empty Optional if no violation occurred or an Optional with the specific violation type

symmetric

public static <T> Optional<ContractViolation> symmetric(T object,
                                                        T anotherObject)

Checks the contract condition for symmetric of the given objects, that means according to Object.equals(Object) that this method should evaluate the following contract condition:

• It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.

Note: The upper list entry is taken from the javadoc from Object.equals(Object)

Type Parameters:

T - the generic type

Parameters:

object - the object

anotherObject - the another object

Returns:

an empty Optional if no violation occurred or an Optional with the specific violation type

transitivity

public static <T> Optional<ContractViolation> transitivity(T a,
                                                           T b,
                                                           T c)

Checks the contract condition for transitivity of the given objects, that means according to Object.equals(Object) that this method should evaluate the following contract condition:

• It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.

Note: The upper list entry is taken from the javadoc from Object.equals(Object)

Type Parameters:

T - the generic type

Parameters:

a - the object

b - other object

c - another object

Returns:

an empty Optional if no violation occurred or an Optional with the specific violation type

nonNull

public static <T> Optional<ContractViolation> nonNull(T object)

Checks the contract condition for non-null condition is given of the given object, that means according to Object.equals(Object) that this method should evaluate the following contract condition:

• For any non-null reference value x, x.equals(null) should return false.

Note: The upper list entry is taken from the javadoc from Object.equals(Object)

Type Parameters:

T - the generic type

Parameters:

object - the object

Returns:

an empty Optional if no violation occurred or an Optional with the specific violation type

consistency

public static <T> Optional<ContractViolation> consistency(T object,
                                                          T anotherObject)

Checks the contract condition for consistency of the given objects, that means according to Object.equals(Object) that this method should evaluate the following contract condition:

• It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.

Note: The upper list entry is taken from the javadoc from Object.equals(Object)

This method calls the same name method with default iterations of 7

Type Parameters:

T - the generic type

Parameters:

object - the object

anotherObject - the another object

Returns:

an empty Optional if no violation occurred or an Optional with the specific violation type

consistency

public static <T> Optional<ContractViolation> consistency(T object,
                                                          T anotherObject,
                                                          int iterations)

Checks the contract condition for consistency of the given objects, that means according to Object.equals(Object) that this method should evaluate the following contract condition:

• It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.

Note: The upper list entry is taken from the javadoc from Object.equals(Object)

Type Parameters:

T - the generic type

Parameters:

object - the object

anotherObject - the another object

iterations - the iterations of call of equals method.

Returns:

an empty Optional if no violation occurred or an Optional with the specific violation type

reflexivityAndNonNull

public static <T> Optional<ContractViolation> reflexivityAndNonNull(T object)

Checks the contract conditions for reflexivity and non null, that means according to Object.equals(Object) that this method should evaluate the following contract condition:

• It is reflexive: for any non-null reference value x, x.equals(x) should return true.
• For any non-null reference value x, x.equals(null) should return false.

Note: The upper list entries is taken from the javadoc from Object.equals(Object)

Type Parameters:

T - the generic type

Parameters:

object - the object

Returns:

an empty Optional if no violation occurred or an Optional with the specific violation type

symmetricAndConsistency

public static <T> Optional<ContractViolation> symmetricAndConsistency(T object,
                                                                      T anotherObject)

Checks the contract conditions for symmetric and consistency of the given objects, that means according to Object.equals(Object) that this method should evaluate the following contract condition:

• It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
• It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.

Note: The upper list entries is taken from the javadoc from Object.equals(Object)

Type Parameters:

T - the generic type

Parameters:

object - the object

anotherObject - the another object

Returns:

an empty Optional if no violation occurred or an Optional with the specific violation type

reflexivityNonNullSymmetricAndConsistency

public static <T> Optional<ContractViolation> reflexivityNonNullSymmetricAndConsistency(T object,
                                                                                        T otherObject)

Checks the contract conditions for reflexivity, non null, symmetric and consistency of the given objects, that means according to Object.equals(Object) that this method should evaluate the following contract condition:

• It is reflexive: for any non-null reference value x, x.equals(x) should return true.
• For any non-null reference value x, x.equals(null) should return false.
• It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
• It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.

Note: The upper list entries is taken from the javadoc from Object.equals(Object)

Type Parameters:

T - the generic type

Parameters:

object - the object

otherObject - the other object

Returns:

an empty Optional if no violation occurred or an Optional with the specific violation type

reflexivityNonNullSymmetricConsistencyAndTransitivity

public static <T> Optional<ContractViolation> reflexivityNonNullSymmetricConsistencyAndTransitivity(T object,
                                                                                                    T otherObject,
                                                                                                    T anotherObject)

Checks the contract conditions for reflexivity, non null, symmetric, consistency and transitivity of the given objects, that means according to Object.equals(Object) that this method should evaluate the following contract condition:

• It is reflexive: for any non-null reference value x, x.equals(x) should return true.
• For any non-null reference value x, x.equals(null) should return false.
• It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
• It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
• It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.

Note: The upper list entries is taken from the javadoc from Object.equals(Object)

Type Parameters:

T - the generic type

Parameters:

object - the object

otherObject - the other object

anotherObject - the another object

Returns:

an empty Optional if no violation occurred or an Optional with the specific violation type