Package org.apache.jasper.compiler

Class ELParser

java.lang.Object

org.apache.jasper.compiler.ELParser

public class ELParser
extends java.lang.Object

This class implements a parser for EL expressions. It takes strings of the form xxx${..}yyy${..}zzz etc, and turn it into a ELNode.Nodes. Currently, it only handles text outside ${..} and functions in ${ ..}.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	ELParser.Char
private static class	ELParser.Id
private static class	ELParser.QuotedString
private static class	ELParser.Token

Field Summary

Fields

Modifier and Type	Field	Description
private ELParser.Token	curToken
private ELNode.Nodes	ELexpr
private boolean	escapeBS
private ELNode.Nodes	expr
private java.lang.String	expression
private int	index
private boolean	isDollarExpr
private ELParser.Token	prevToken
private static java.lang.String[]	reservedWords

Constructor Summary

Constructors

Constructor	Description
ELParser(java.lang.String expression)

Method Summary

Modifier and Type	Method	Description
private int	getIndex()
private boolean	hasNext()
private boolean	hasNextChar()
private boolean	isELReserved(java.lang.String id)	Test if an id is a reserved word in EL
private char	nextChar()
private ELParser.Token	nextToken()
static ELNode.Nodes	parse(java.lang.String expression)	Parse an EL expression
private ELNode.Nodes	parseEL()	Parse an EL expression string '${...} or #{...}'
private boolean	parseFunction()	Parse for a function FunctionInvokation ::= (identifier ':')? identifier '(' (Expression (,Expression)*)? ')' Note: currently we don't parse arguments In EL 1.2, method can include parameters, so we need to exclude cases such as a.b().
private ELParser.Token	parseQuotedChars(char quote)
private int	peekChar()
private void	setIndex(int i)
private void	skipSpaces()
private java.lang.String	skipUntilEL()	Skip until an EL expression ('${' or '#{') is reached, allowing escape sequences '\\', '\$', and '\#'.

Methods inherited from class java.lang.Object

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

Field Detail

curToken

private ELParser.Token curToken

prevToken

private ELParser.Token prevToken

expr

private ELNode.Nodes expr

ELexpr

private ELNode.Nodes ELexpr

index

private int index

expression

private java.lang.String expression

escapeBS

private boolean escapeBS

isDollarExpr

private boolean isDollarExpr

reservedWords

private static final java.lang.String[] reservedWords

Constructor Detail

ELParser

public ELParser(java.lang.String expression)

Method Detail

parse

public static ELNode.Nodes parse(java.lang.String expression)

Parse an EL expression

Parameters:

expression - The input expression string of the form ( (Char* | (('${' | '#{') Char* '}') )+

Returns:

Parsed EL expression in ELNode.Nodes

parseEL

private ELNode.Nodes parseEL()

Parse an EL expression string '${...} or #{...}'

Returns:

An ELNode.Nodes representing the EL expression TODO: Currently only parsed into functions and text strings. This should be rewritten for a full parser.

parseFunction

private boolean parseFunction()

Parse for a function FunctionInvokation ::= (identifier ':')? identifier '(' (Expression (,Expression)*)? ')' Note: currently we don't parse arguments In EL 1.2, method can include parameters, so we need to exclude cases such as a.b().

isELReserved

private boolean isELReserved(java.lang.String id)

Test if an id is a reserved word in EL

skipUntilEL

private java.lang.String skipUntilEL()

Skip until an EL expression ('${' or '#{') is reached, allowing escape sequences '\\', '\$', and '\#'.

Returns:

The text string up to the EL expression

hasNext

private boolean hasNext()

nextToken

private ELParser.Token nextToken()

parseQuotedChars

private ELParser.Token parseQuotedChars(char quote)

skipSpaces

private void skipSpaces()

hasNextChar

private boolean hasNextChar()

nextChar

private char nextChar()

peekChar

private int peekChar()

getIndex

private int getIndex()

setIndex

private void setIndex(int i)