# Class VariableMapperFactory

java.lang.Object
jakarta.el.VariableMapper
org.apache.el.lang.VariableMapperFactory

public class VariableMapperFactory extends VariableMapper
Factory for creating variable mappers that track variable resolutions.

## Constructor Summary

Constructors
Constructor
Description
`VariableMapperFactory(VariableMapper target)`
Constructs a new VariableMapperFactory.

## Method Summary

Modifier and Type
Method
Description
`VariableMapper`
`create()`
Returns the momento mapper containing all resolved variables.
`ValueExpression`
`resolveVariable(String variable)`
Resolves a variable name to its corresponding ValueExpression.
`ValueExpression`
`setVariable(String variable, ValueExpression expression)`
Sets or removes a variable mapping.

### Methods inherited from class Object

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

## Constructor Details

### VariableMapperFactory

public VariableMapperFactory(VariableMapper target)
Constructs a new VariableMapperFactory.

Parameters:
  `target` - The target variable mapper to delegate to
Throws:
  `NullPointerException` - if target is null

## Method Details

### create

public VariableMapper create()
Returns the momento mapper containing all resolved variables.

Returns:
  the momento mapper, or `null` if no variables have been resolved

### resolveVariable

public ValueExpression resolveVariable(String variable)
Description copied from class: `jakarta.el.VariableMapper`
Resolves a variable name to its corresponding ValueExpression.

Specified by:
  `resolveVariable` in class `VariableMapper`
Parameters:
  `variable` - the name of the variable to resolve
Returns:
  the ValueExpression for the variable, or `null` if not found

### setVariable

public ValueExpression setVariable(String variable, ValueExpression expression)
Description copied from class: `jakarta.el.VariableMapper`
Sets or removes a variable mapping.

Specified by:
  `setVariable` in class `VariableMapper`
Parameters:
  `variable` - the name of the variable
  `expression` - the ValueExpression to associate with the variable, or `null` to remove the mapping
Returns:
  the previous ValueExpression for the variable, or `null` if there was no mapping