/*
Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
The MySQL Connector/J is licensed under the terms of the GPLv2
<http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most MySQL Connectors.
There are special exceptions to the terms and conditions of the GPLv2 as it is applied to
this software, see the FLOSS License Exception
<http://www.mysql.com/about/legal/licensing/foss-exception.html>.
This program is free software; you can redistribute it and/or modify it under the terms
of the GNU General Public License as published by the Free Software Foundation; version 2
of the License.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this
program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth
Floor, Boston, MA 02110-1301 USA
*/
package com.mysql.jdbc;
/**
* EscapeTokenizer breaks up an SQL statement into SQL and escape code parts.
*
* @author Mark Matthews
*/
public class EscapeTokenizer {
// ~ Instance fields
// --------------------------------------------------------
private int bracesLevel = 0;
private boolean emittingEscapeCode = false;
private boolean inComment = false;
private boolean inQuotes = false;
private char lastChar = 0;
private char lastLastChar = 0;
private int pos = 0;
private char quoteChar = 0;
private boolean sawVariableUse = false;
private String source = null;
private int sourceLength = 0;
// ~ Constructors
// -----------------------------------------------------------
/**
* Creates a new EscapeTokenizer object.
*
* @param s
* the string to tokenize
*/
public EscapeTokenizer(String s) {
this.source = s;
this.sourceLength = s.length();
this.pos = 0;
}
// ~ Methods
// ----------------------------------------------------------------
/**
* Does this tokenizer have more tokens available?
*
* @return if this tokenizer has more tokens available
*/
public synchronized boolean hasMoreTokens() {
return (this.pos < this.sourceLength);
}
/**
* Returns the next token
*
* @return the next token.
*/
public synchronized String nextToken() {
StringBuffer tokenBuf = new StringBuffer();
if (this.emittingEscapeCode) {
tokenBuf.append("{"); //$NON-NLS-1$
this.emittingEscapeCode = false;
}
for (; this.pos < this.sourceLength; this.pos++) {
char c = this.source.charAt(this.pos);
// Detect variable usage
if (!this.inQuotes && c == '@') {
this.sawVariableUse = true;
}
if ((c == '\'' || c == '"') && !inComment) {
if (this.inQuotes && c == quoteChar) {
if (this.pos + 1 < this.sourceLength) {
if (this.source.charAt(this.pos + 1) == quoteChar) {
// Doubled-up quote escape, if the first quote isn't already escaped
if (this.lastChar != '\\') {
tokenBuf.append(quoteChar);
tokenBuf.append(quoteChar);
this.pos++;
continue;
}
}
}
}
if (this.lastChar != '\\') {
if (this.inQuotes) {
if (this.quoteChar == c) {
this.inQuotes = false;
}
} else {
this.inQuotes = true;
this.quoteChar = c;
}
} else if (this.lastLastChar == '\\') {
if (this.inQuotes) {
if (this.quoteChar == c) {
this.inQuotes = false;
}
} else {
this.inQuotes = true;
this.quoteChar = c;
}
}
tokenBuf.append(c);
} else if (c == '-') {
if ((this.lastChar == '-')
&& ((this.lastLastChar != '\\') && !this.inQuotes)) {
this.inComment = true;
}
tokenBuf.append(c);
} else if ((c == '\n') || (c == '\r')) {
this.inComment = false;
tokenBuf.append(c);
} else if (c == '{') {
if (this.inQuotes || this.inComment) {
tokenBuf.append(c);
} else {
this.bracesLevel++;
if (this.bracesLevel == 1) {
this.pos++;
this.emittingEscapeCode = true;
return tokenBuf.toString();
}
tokenBuf.append(c);
}
} else if (c == '}') {
tokenBuf.append(c);
if (!this.inQuotes && !this.inComment) {
this.lastChar = c;
this.bracesLevel--;
if (this.bracesLevel == 0) {
this.pos++;
return tokenBuf.toString();
}
}
} else {
tokenBuf.append(c);
}
this.lastLastChar = this.lastChar;
this.lastChar = c;
}
return tokenBuf.toString();
}
boolean sawVariableUse() {
return this.sawVariableUse;
}
}