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Expression.javaAPI DocGlassfish v2 API3259Fri May 04 22:34:28 BST 2007javax.servlet.jsp.el

Expression

public abstract class Expression extends Object

The abstract class for a prepared expression.

An instance of an Expression can be obtained via from an ExpressionEvaluator instance.

An Expression may or not have done a syntactic parse of the expression. A client invoking the evaluate() method should be ready for the case where ELParseException exceptions are raised.

deprecated
As of JSP 2.1, replaced by {@link javax.el.ValueExpression}
since
JSP 2.0

Fields Summary
Constructors Summary
Methods Summary
public abstract java.lang.Objectevaluate(VariableResolver vResolver)
Evaluates an expression that was previously prepared. In some implementations preparing an expression involves full syntactic validation, but others may not do so. Evaluating the expression may raise an ELParseException as well as other ELExceptions due to run-time evaluation.

param
vResolver A VariableResolver instance that can be used at runtime to resolve the name of implicit objects into Objects.
return
The result of the expression evaluation.
exception
ELException Thrown if the expression evaluation failed.