Class ConstantTransformer<I,O>
- java.lang.Object
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- org.apache.commons.collections4.functors.ConstantTransformer<I,O>
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- All Implemented Interfaces:
java.io.Serializable
,Transformer<I,O>
public class ConstantTransformer<I,O> extends java.lang.Object implements Transformer<I,O>, java.io.Serializable
Transformer implementation that returns the same constant each time.No check is made that the object is immutable. In general, only immutable objects should use the constant factory. Mutable objects should use the prototype factory.
- Since:
- 3.0
- See Also:
- Serialized Form
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Field Summary
Fields Modifier and Type Field Description private O
iConstant
The closures to call in turnstatic Transformer
NULL_INSTANCE
Returns null each timeprivate static long
serialVersionUID
Serial version UID
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Constructor Summary
Constructors Constructor Description ConstantTransformer(O constantToReturn)
Constructor that performs no validation.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description static <I,O>
Transformer<I,O>constantTransformer(O constantToReturn)
Transformer method that performs validation.boolean
equals(java.lang.Object obj)
O
getConstant()
Gets the constant.int
hashCode()
static <I,O>
Transformer<I,O>nullTransformer()
Get a typed null instance.O
transform(I input)
Transforms the input by ignoring it and returning the stored constant instead.
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Field Detail
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serialVersionUID
private static final long serialVersionUID
Serial version UID- See Also:
- Constant Field Values
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NULL_INSTANCE
public static final Transformer NULL_INSTANCE
Returns null each time
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iConstant
private final O iConstant
The closures to call in turn
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Constructor Detail
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ConstantTransformer
public ConstantTransformer(O constantToReturn)
Constructor that performs no validation. UseconstantTransformer
if you want that.- Parameters:
constantToReturn
- the constant to return each time
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Method Detail
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nullTransformer
public static <I,O> Transformer<I,O> nullTransformer()
Get a typed null instance.- Type Parameters:
I
- the input typeO
- the output type- Returns:
- Transformer<I, O> that always returns null.
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constantTransformer
public static <I,O> Transformer<I,O> constantTransformer(O constantToReturn)
Transformer method that performs validation.- Type Parameters:
I
- the input typeO
- the output type- Parameters:
constantToReturn
- the constant object to return each time in the factory- Returns:
- the
constant
factory.
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transform
public O transform(I input)
Transforms the input by ignoring it and returning the stored constant instead.- Specified by:
transform
in interfaceTransformer<I,O>
- Parameters:
input
- the input object which is ignored- Returns:
- the stored constant
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getConstant
public O getConstant()
Gets the constant.- Returns:
- the constant
- Since:
- 3.1
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equals
public boolean equals(java.lang.Object obj)
- Overrides:
equals
in classjava.lang.Object
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hashCode
public int hashCode()
- Overrides:
hashCode
in classjava.lang.Object
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