Constructor Detail

• ExpressionEvaluatorImpl

  public ExpressionEvaluatorImpl(PageContext pageContext)

  Constructor

Method Detail

• parseExpression

  public Expression parseExpression(java.lang.String expression,
                                    java.lang.Class expectedType,
                                    FunctionMapper fMapper)
                             throws ELException

  Description copied from class: ExpressionEvaluator
  Prepare an expression for later evaluation. This method should perform syntactic validation of the expression; if in doing so it detects errors, it should raise an ELParseException.

  Specified by:

  parseExpression in class ExpressionEvaluator

  Parameters:

  expression - The expression to be evaluated.

  expectedType - The expected type of the result of the evaluation

  fMapper - A FunctionMapper to resolve functions found in the expression. It can be null, in which case no functions are supported for this invocation. The ExpressionEvaluator must not hold on to the FunctionMapper reference after returning from parseExpression(). The Expression object returned must invoke the same functions regardless of whether the mappings in the provided FunctionMapper instance change between calling ExpressionEvaluator.parseExpression() and Expression.evaluate().

  Returns:

  The Expression object encapsulating the arguments.

  Throws:

  ELException - Thrown if parsing errors were found.

• evaluate

  public java.lang.Object evaluate(java.lang.String expression,
                                   java.lang.Class expectedType,
                                   VariableResolver vResolver,
                                   FunctionMapper fMapper)
                            throws ELException

  Description copied from class: ExpressionEvaluator
  Evaluates an expression. This method may perform some syntactic validation and, if so, it should raise an ELParseException error if it encounters syntactic errors. EL evaluation errors should cause an ELException to be raised.

  Specified by:

  evaluate in class ExpressionEvaluator

  Parameters:

  expression - The expression to be evaluated.

  expectedType - The expected type of the result of the evaluation

  vResolver - A VariableResolver instance that can be used at runtime to resolve the name of implicit objects into Objects.

  fMapper - A FunctionMapper to resolve functions found in the expression. It can be null, in which case no functions are supported for this invocation.

  Returns:

  The result of the expression evaluation.

  Throws:

  ELException - Thrown if the expression evaluation failed.