VariableMapper (EL 6.0 API Documentation - Apache Tomcat 11.0.23)
Description: declaration: package: jakarta.el, class: VariableMapper

# Class VariableMapper

java.lang.Object
jakarta.el.VariableMapper

public abstract class VariableMapper extends Object
Manages the mapping between variable names and their corresponding `ValueExpression` instances within an `ELContext`. Variable mappings allow EL expressions to reference named variables that resolve to computed values.

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `VariableMapper()`
  Default constructor for subclasses.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `abstract ValueExpression`
  `resolveVariable(String variable)`
  Resolves a variable name to its corresponding ValueExpression.
  `abstract 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

  - ### VariableMapper

    public VariableMapper()
    Default constructor for subclasses.

- ## Method Details

  - ### resolveVariable

    public abstract ValueExpression resolveVariable(String variable)
    Resolves a variable name to its corresponding ValueExpression.
    Parameters:
      `variable` - the name of the variable to resolve
    Returns:
      the ValueExpression for the variable, or `null` if not found

  - ### setVariable

    public abstract ValueExpression setVariable(String variable, ValueExpression expression)
    Sets or removes a variable mapping.
    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