VariableMapper (Jakarta Expression Language API documentation)

java.lang.Object
- jakarta.el.VariableMapper

```
public abstract class VariableMapper
extends Object
```
The interface to a map between Jakarta Expression Language variables and the Jakarta Expression Language expressions they are associated with.

Since:

Jakarta Server Pages 2.1

Constructor Summary

Constructors
Constructor Description

VariableMapper()

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`abstract ValueExpression`	`resolveVariable(String variable)`
`abstract ValueExpression`	`setVariable(String variable, ValueExpression expression)`	Assign a ValueExpression to an Jakarta Expression Language variable, replacing any previously assignment to the same variable.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - VariableMapper
```
public VariableMapper()
```
- Method Detail
  - resolveVariable
```
public abstract ValueExpression resolveVariable(String variable)
```
    Parameters:
    
    variable - The variable name
    
    Returns:
    
    the ValueExpression assigned to the variable, null if there is no previous assignment to this variable.
  - setVariable
```
public abstract ValueExpression setVariable(String variable,
                                            ValueExpression expression)
```
    Assign a ValueExpression to an Jakarta Expression Language variable, replacing any previously assignment to the same variable. The assignment for the variable is removed if the expression is null.
    
    Parameters:
    
    variable - The variable name
    
    expression - The ValueExpression to be assigned to the variable.
    
    Returns:
    
    The previous ValueExpression assigned to this variable, null if there is no previous assignment to this variable.