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Expression.java API Doc Apache Tomcat 6.0.14 2040 Fri Jul 20 04:20:34 BST 2007 javax.servlet.jsp.el

Expression

java.lang.Object

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.

since: 2.0
deprecated

Fields Summary
Constructors Summary
Methods Summary
public abstract java.lang.Object evaluate(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.