/**
* Alipay.com Inc.
* Copyright (c) 2004-2012 All Rights Reserved.
*/
package com.alipay.zdal.parser.sql.parser;
/**
*
* @author ����
* @version $Id: SQLParser.java, v 0.1 2012-11-17 ����3:54:20 Exp $
*/
public class SQLParser {
protected final Lexer lexer;
public SQLParser(String sql) {
this(new Lexer(sql));
this.lexer.nextToken();
}
public SQLParser(Lexer lexer) {
this.lexer = lexer;
}
public final Lexer getLexer() {
return lexer;
}
protected boolean identifierEquals(String text) {
return lexer.token() == Token.IDENTIFIER && lexer.stringVal().equalsIgnoreCase(text);
}
protected void acceptIdentifier(String text) {
if (identifierEquals(text)) {
lexer.nextToken();
} else {
setErrorEndPos(lexer.pos());
throw new SQLParserException("syntax error, expect " + text + ", actual "
+ lexer.token());
}
}
protected String as() throws ParserException {
String alias = null;
if (lexer.token() == Token.AS) {
lexer.nextToken();
if (lexer.token() == Token.LITERAL_ALIAS) {
alias = '"' + lexer.stringVal() + '"';
lexer.nextToken();
return alias;
}
if (lexer.token() == Token.IDENTIFIER) {
alias = lexer.stringVal();
lexer.nextToken();
return alias;
}
if (lexer.token() == Token.LITERAL_CHARS) {
alias = "'" + lexer.stringVal() + "'";
lexer.nextToken();
return alias;
}
if (lexer.token() == Token.KEY || lexer.token() == Token.CASE) {
alias = lexer.token.name();
lexer.nextToken();
return alias;
}
switch (lexer.token()) {
case KEY:
alias = lexer.token().name();
lexer.nextToken();
return alias;
default:
break;
}
throw new ParserException("Error : " + lexer.token());
}
if (lexer.token() == Token.LITERAL_ALIAS) {
alias = '"' + lexer.stringVal() + '"';
lexer.nextToken();
} else if (lexer.token() == Token.IDENTIFIER) {
alias = lexer.stringVal();
lexer.nextToken();
} else if (lexer.token() == Token.LITERAL_CHARS) {
alias = "'" + lexer.stringVal() + "'";
lexer.nextToken();
} else if (lexer.token() == Token.CASE) {
alias = lexer.token.name();
lexer.nextToken();
}
switch (lexer.token()) {
case KEY:
alias = lexer.token().name();
lexer.nextToken();
return alias;
default:
break;
}
return alias;
}
public void accept(Token token) {
if (lexer.token() == token) {
lexer.nextToken();
} else {
setErrorEndPos(lexer.pos());
throw new SQLParserException("syntax error, expect " + token + ", actual "
+ lexer.token() + " " + lexer.stringVal());
}
}
public void match(Token token) {
if (lexer.token() != token) {
throw new SQLParserException("syntax error, expect " + token + ", actual "
+ lexer.token() + " " + lexer.stringVal());
}
}
private int errorEndPos = -1;
protected void setErrorEndPos(int errPos) {
if (errPos > errorEndPos) {
errorEndPos = errPos;
}
}
}