Apache Commons Collections 4.4 · org.apache.commons.collections4.functors.ConstantTransformer

Modifier and Type	Field and Description
private final O	iConstant The closures to call in turn
public static final Transformer<I, O>	NULL_INSTANCE Returns null each time
private static final long	serialVersionUID Serial version UID

Access	Constructor and Description
public	ConstantTransformer(final O the constant to return each time constantToReturn) Constructor that performs no validation.

Method Summary

Modifier and Type	Method and Description
public static < the input type I, the output type O> Transformer<I, O>	Returns: the `constant` factory. constantTransformer(final O the constant object to return each time in the factory constantToReturn) Transformer method that performs validation.
public boolean	equals(final Object the reference object with which to compare. obj) Overrides java.lang.Object.equals. Indicates whether some other object is "equal to" this one.
public O	Returns: the constant getConstant() Gets the constant.
public int	hashCode() Overrides java.lang.Object.hashCode. Returns a hash code value for the object.
public static < the input type I, the output type O> Transformer<I, O>	Returns: Transformer<I, O> that always returns null. nullTransformer() Get a typed null instance.
public O	Returns: the stored constant transform(final I the input object which is ignored input) Implements org.apache.commons.collections4.Transformer.transform. Transforms the input by ignoring it and returning the stored constant instead.

Inherited from java.lang.Object:: clone finalize getClass notify notifyAll toString wait wait wait

iConstant	back to summary
private final O iConstant The closures to call in turn

NULL_INSTANCE	back to summary
public static final Transformer<I, O> NULL_INSTANCE Returns null each time Annotations @SuppressWarnings:rawtypes

serialVersionUID	back to summary
private static final long serialVersionUID Serial version UID

ConstantTransformer	back to summary
public ConstantTransformer(final O constantToReturn) Constructor that performs no validation. Use `constantTransformer` if you want that. Parameters constantToReturn:O the constant to return each time

Method Detail

constantTransformer back to summary

constantTransformer	back to summary
public static <I, O> Transformer<I, O> constantTransformer(final O constantToReturn) Transformer method that performs validation. Parameters <I> the input type <O> the output type constantToReturn:O the constant object to return each time in the factory Returns:Transformer<I, O> the `constant` factory.

public static <I, O> Transformer<I, O> constantTransformer(final O constantToReturn)

Transformer method that performs validation.

Parameters

<I>: the input type
<O>: the output type
constantToReturn:O: the constant object to return each time in the factory

Returns:Transformer<I, O>

the constant factory.

equals back to summary

equals	back to summary
public boolean equals(final Object obj) Overrides java.lang.Object.equals. Doc from java.lang.Object.equals. Indicates whether some other object is "equal to" this one. The `equals` method implements an equivalence relation on non-null object references: It is reflexive: for any non-null reference value `x`, `x.equals(x)` should return `true`. 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 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`. 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. For any non-null reference value `x`, `x.equals(null)` should return `false`. An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes. Parameters obj:Object the reference object with which to compare. Returns:boolean `true` if this object is the same as the obj argument; `false` otherwise. Annotations @Override

public boolean equals(final Object obj)

Overrides java.lang.Object.equals.

Doc from java.lang.Object.equals.

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

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

An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.

Parameters

obj:Object: the reference object with which to compare.

Returns:boolean

true if this object is the same as the obj argument; false otherwise.

Annotations

@Override

getConstant	back to summary
public O getConstant() Gets the constant. Returns:O the constant Since 3.1

getConstant

back to summary

public O getConstant()

Gets the constant.

Returns:O: the constant
Since: 3.1

hashCode back to summary

hashCode	back to summary
public int hashCode() Overrides java.lang.Object.hashCode. Doc from java.lang.Object.hashCode. Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by `java.util.HashMap`. The general contract of `hashCode` is: Whenever it is invoked on the same object more than once during an execution of a Java application, the `hashCode` method must consistently return the same integer, provided no information used in `equals` comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. If two objects are equal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce the same integer result. It is not required that if two objects are unequal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables. Returns:int a hash code value for this object. Annotations @Override

public int hashCode()

Overrides java.lang.Object.hashCode.

Doc from java.lang.Object.hashCode.

Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by java.util.HashMap.

The general contract of hashCode is:

Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

Returns:int

a hash code value for this object.

Annotations

@Override

nullTransformer	back to summary
public static <I, O> Transformer<I, O> nullTransformer() Get a typed null instance. Parameters <I> the input type <O> the output type Returns:Transformer<I, O> Transformer<I, O> that always returns null.

nullTransformer

back to summary

public static <I, O> Transformer<I, O> nullTransformer()

Get a typed null instance.

Parameters

<I>: the input type
<O>: the output type

Returns:Transformer<I, O>

Transformer<I, O> that always returns null.

transform	back to summary
public O transform(final I input) Implements org.apache.commons.collections4.Transformer.transform. Transforms the input by ignoring it and returning the stored constant instead. Parameters input:I the input object which is ignored Returns:O the stored constant Annotations @Override

transform

back to summary

public O transform(final I input)

Implements org.apache.commons.collections4.Transformer.transform.

Transforms the input by ignoring it and returning the stored constant instead.

Parameters