org.apache.catalina.ssi.ExpressionTokenizer Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of payara-micro Show documentation
Show all versions of payara-micro Show documentation
Micro Distribution of the Payara Project
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*
*
* This file incorporates work covered by the following copyright and
* permission notice:
*
* Copyright 2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.catalina.ssi;
/**
* Parses an expression string to return the individual tokens. This is
* patterned similar to the StreamTokenizer in the JDK but customized for SSI
* conditional expression parsing.
*
* @version $Revision: 1.2 $
* @author Paul Speed
*/
public class ExpressionTokenizer {
public static final int TOKEN_STRING = 0;
public static final int TOKEN_AND = 1;
public static final int TOKEN_OR = 2;
public static final int TOKEN_NOT = 3;
public static final int TOKEN_EQ = 4;
public static final int TOKEN_NOT_EQ = 5;
public static final int TOKEN_RBRACE = 6;
public static final int TOKEN_LBRACE = 7;
public static final int TOKEN_GE = 8;
public static final int TOKEN_LE = 9;
public static final int TOKEN_GT = 10;
public static final int TOKEN_LT = 11;
public static final int TOKEN_END = 12;
private char[] expr;
private String tokenVal = null;
private int index;
private int length;
/**
* Creates a new parser for the specified expression.
*/
public ExpressionTokenizer(String expr) {
this.expr = expr.trim().toCharArray();
this.length = this.expr.length;
}
/**
* Returns true if there are more tokens.
*/
public boolean hasMoreTokens() {
return index < length;
}
/**
* Returns the current index for error reporting purposes.
*/
public int getIndex() {
return index;
}
protected boolean isMetaChar(char c) {
return Character.isWhitespace(c) || c == '(' || c == ')' || c == '!'
|| c == '<' || c == '>' || c == '|' || c == '&' || c == '=';
}
/**
* Returns the next token type and initializes any state variables
* accordingly.
*/
public int nextToken() {
// Skip any leading white space
while (index < length && Character.isWhitespace(expr[index]))
index++;
// Clear the current token val
tokenVal = null;
if (index == length) return TOKEN_END; // End of string
int start = index;
char currentChar = expr[index];
char nextChar = (char)0;
index++;
if (index < length) nextChar = expr[index];
// Check for a known token start
switch (currentChar) {
case '(' :
return TOKEN_LBRACE;
case ')' :
return TOKEN_RBRACE;
case '=' :
return TOKEN_EQ;
case '!' :
if (nextChar == '=') {
index++;
return TOKEN_NOT_EQ;
} else {
return TOKEN_NOT;
}
case '|' :
if (nextChar == '|') {
index++;
return TOKEN_OR;
}
break;
case '&' :
if (nextChar == '&') {
index++;
return TOKEN_AND;
}
break;
case '>' :
if (nextChar == '=') {
index++;
return TOKEN_GE; // Greater than or equal
} else {
return TOKEN_GT; // Greater than
}
case '<' :
if (nextChar == '=') {
index++;
return TOKEN_LE; // Less than or equal
} else {
return TOKEN_LT; // Less than
}
default :
// Otherwise it's a string
break;
}
int end = index;
// If it's a quoted string then end is the next unescaped quote
if (currentChar == '"' || currentChar == '\'') {
char endChar = currentChar;
boolean escaped = false;
start++;
for (; index < length; index++) {
if (expr[index] == '\\' && !escaped) {
escaped = true;
continue;
}
if (expr[index] == endChar && !escaped) break;
escaped = false;
}
end = index;
index++; // Skip the end quote
} else {
// End is the next whitespace character
for (; index < length; index++) {
if (isMetaChar(expr[index])) break;
}
end = index;
}
// Extract the string from the array
this.tokenVal = new String(expr, start, end - start);
return TOKEN_STRING;
}
/**
* Returns the String value of the token if it was type TOKEN_STRING.
* Otherwise null is returned.
*/
public String getTokenValue() {
return tokenVal;
}
}