org.apache.commons.el

Class Expression

java.lang.Object

org.apache.commons.el.Expression

Direct Known Subclasses:

BinaryOperatorExpression, ComplexValue, ConditionalExpression, ExpressionString, FunctionInvocation, Literal, NamedValue, UnaryOperatorExpression

public abstract class Expression
extends Object

The abstract class from which all expression types derive.

Version:

$Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: bayard $

Author:

Nathan Abramson - Art Technology Group, Shawn Bayern

Constructor Summary

Constructors

Constructor and Description
Expression()

Method Summary

Methods

Modifier and Type	Method and Description
abstract Expression	bindFunctions(javax.servlet.jsp.el.FunctionMapper functions) Returns an expression with all FunctionInvocations replaced by BoundFunctionInvocations.
abstract Object	evaluate(javax.servlet.jsp.el.VariableResolver pResolver, javax.servlet.jsp.el.FunctionMapper functions) Evaluates the expression in the given context
abstract String	getExpressionString() Returns the expression in the expression language syntax

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Expression

public Expression()

Method Detail

getExpressionString

public abstract String getExpressionString()

Returns the expression in the expression language syntax

evaluate

public abstract Object evaluate(javax.servlet.jsp.el.VariableResolver pResolver,
              javax.servlet.jsp.el.FunctionMapper functions)
                         throws javax.servlet.jsp.el.ELException

Evaluates the expression in the given context

Throws:

javax.servlet.jsp.el.ELException

bindFunctions

public abstract Expression bindFunctions(javax.servlet.jsp.el.FunctionMapper functions)
                                  throws javax.servlet.jsp.el.ELException

Returns an expression with all FunctionInvocations replaced by BoundFunctionInvocations.

Parameters:

functions - the functions to use in this transformation

Returns:

an Expression identical to this expression except with all FunctionInvocations replaced by BoundFunctionInvocations.

Throws:

javax.servlet.jsp.el.ELException - if any of the functions in this Expression are not present in functions