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Jakarta Expression Language Implementation
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/*
* Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2021 Payara Services Ltd.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package com.sun.el.parser;
/**
* This exception is thrown when parse errors are encountered. You can explicitly create objects of this exception type
* by calling the method generateParseException in the generated parser.
*
* You can modify this class to customize your error reporting mechanisms so long as you retain the public fields.
*/
public class ParseException extends Exception {
/**
* This constructor is used by the method "generateParseException" in the generated parser. Calling this constructor
* generates a new object of this type with the fields "currentToken", "expectedTokenSequences", and "tokenImage" set.
* The boolean flag "specialConstructor" is also set to true to indicate that this constructor was used to create this
* object. This constructor calls its super class with the empty string to force the "toString" method of parent class
* "Throwable" to print the error message in the form: ParseException:
*/
public ParseException(Token currentTokenVal, int[][] expectedTokenSequencesVal, String[] tokenImageVal) {
super("");
specialConstructor = true;
currentToken = currentTokenVal;
expectedTokenSequences = expectedTokenSequencesVal;
tokenImage = tokenImageVal;
}
/**
* The following constructors are for use by you for whatever purpose you can think of. Constructing the exception in
* this manner makes the exception behave in the normal way - i.e., as documented in the class "Throwable". The fields
* "errorToken", "expectedTokenSequences", and "tokenImage" do not contain relevant information. The JavaCC generated
* code does not use these constructors.
*/
public ParseException() {
super();
specialConstructor = false;
}
public ParseException(String message) {
super(message);
specialConstructor = false;
}
/**
* This variable determines which constructor was used to create this object and thereby affects the semantics of the
* "getMessage" method (see below).
*/
protected boolean specialConstructor;
/**
* This is the last token that has been consumed successfully. If this object has been created due to a parse error, the
* token followng this token will (therefore) be the first error token.
*/
public Token currentToken;
/**
* Each entry in this array is an array of integers. Each array of integers represents a sequence of tokens (by their
* ordinal values) that is expected at this point of the parse.
*/
public int[][] expectedTokenSequences;
/**
* This is a reference to the "tokenImage" array of the generated parser within which the parse error occurred. This
* array is defined in the generated ...Constants interface.
*/
public String[] tokenImage;
/**
* This method has the standard behavior when this object has been created using the standard constructors. Otherwise,
* it uses "currentToken" and "expectedTokenSequences" to generate a parse error message and returns it. If this object
* has been created due to a parse error, and you do not catch it (it gets thrown from the parser), then this method is
* called during the printing of the final stack trace, and hence the correct error message gets displayed.
*/
@Override
public String getMessage() {
if (!specialConstructor) {
return super.getMessage();
}
String expected = "";
int maxSize = 0;
for (int i = 0; i < expectedTokenSequences.length; i++) {
if (maxSize < expectedTokenSequences[i].length) {
maxSize = expectedTokenSequences[i].length;
}
for (int j = 0; j < expectedTokenSequences[i].length; j++) {
expected += tokenImage[expectedTokenSequences[i][j]] + " ";
}
if (expectedTokenSequences[i][expectedTokenSequences[i].length - 1] != 0) {
expected += "...";
}
expected += eol + " ";
}
String retval = "Encountered \"";
Token tok = currentToken.next;
for (int i = 0; i < maxSize; i++) {
if (i != 0) {
retval += " ";
}
if (tok.kind == 0) {
retval += tokenImage[0];
break;
}
retval += add_escapes(tok.image);
tok = tok.next;
}
retval += "\" at line " + currentToken.next.beginLine + ", column " + currentToken.next.beginColumn;
retval += "." + eol;
if (expectedTokenSequences.length == 1) {
retval += "Was expecting:" + eol + " ";
} else {
retval += "Was expecting one of:" + eol + " ";
}
retval += expected;
return retval;
}
/**
* The end of line string for this machine.
*/
protected String eol = System.getProperty("line.separator", "\n");
/**
* Used to convert raw characters to their escaped version when these raw version cannot be used as part of an ASCII
* string literal.
*/
protected String add_escapes(String str) {
StringBuilder retval = new StringBuilder();
char ch;
for (int i = 0; i < str.length(); i++) {
switch (str.charAt(i)) {
case 0:
continue;
case '\b':
retval.append("\\b");
continue;
case '\t':
retval.append("\\t");
continue;
case '\n':
retval.append("\\n");
continue;
case '\f':
retval.append("\\f");
continue;
case '\r':
retval.append("\\r");
continue;
case '\"':
retval.append("\\\"");
continue;
case '\'':
retval.append("\\\'");
continue;
case '\\':
retval.append("\\\\");
continue;
default:
if ((ch = str.charAt(i)) < 0x20 || ch > 0x7e) {
String s = "0000" + Integer.toString(ch, 16);
retval.append("\\u" + s.substring(s.length() - 4, s.length()));
} else {
retval.append(ch);
}
continue;
}
}
return retval.toString();
}
}