/*
* Copyright 2008 biaoping.yin
*
* 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 com.frameworkset.orm.sql;
/*
*
* 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.
*/
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;
/**
* A simple Scanner implementation that scans an
* sql file into usable tokens. Used by SQLToAppData.
*
* @author <a href="mailto:leon@opticode.co.za">Leon Messerschmidt</a>
* @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a>
* @author <a href="mailto:andyhot@di.uoa.gr">Andreas Andreou</a>
* @version $Id: SQLScanner.java,v 1.4 2004/02/22 06:27:20 jmcnally Exp $
*/
public class SQLScanner
{
/** white spaces */
private static final String WHITE = "\f\r\t\n ";
/** alphabetic characters */
private static final String ALFA
= "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
/** numbers */
private static final String NUMER = "0123456789";
/** alphanumeric */
private static final String ALFANUM = ALFA + NUMER;
/** special characters */
private static final String SPECIAL = ";(),'";
/** comment */
private static final char COMMENT_POUND = '#';
/** comment */
private static final char COMMENT_SLASH = '/';
/** comment */
private static final char COMMENT_STAR = '*';
/** comment */
private static final char COMMENT_DASH = '-';
/** the input reader */
private Reader in;
/** character */
private int chr;
/** token */
private String token;
/** list of tokens */
private List tokens;
/** line */
private int line;
/** column */
private int col;
/**
* Creates a new scanner with no Reader
*/
public SQLScanner()
{
this(null);
}
/**
* Creates a new scanner with an Input Reader
*
* @param input the input reader
*/
public SQLScanner(Reader input)
{
setInput(input);
}
/**
* Set the Input
*
* @param input the input reader
*/
public void setInput(Reader input)
{
in = input;
}
/**
* Reads the next character and increments the line and column counters.
*
* @throws IOException If an I/O error occurs
*/
private void readChar() throws IOException
{
boolean wasLine = (char) chr == '\r';
chr = in.read();
System.out.println("readchar:" + (char)chr);
if ((char) chr == '\n' || (char) chr == '\r' || (char) chr == '\f')
{
col = 0;
if (!wasLine || (char) chr != '\n')
{
line++;
}
}
else
{
col++;
}
}
/**
* Scans an identifier.
*
* @throws IOException If an I/O error occurs
*/
private void scanIdentifier () throws IOException
{
token = "";
char c = (char) chr;
while (chr != -1 && WHITE.indexOf(c) == -1 && SPECIAL.indexOf(c) == -1)
{
token = token + (char) chr;
readChar();
c = (char) chr;
}
int start = col - token.length();
System.out.println("token:" + token);
tokens.add(new Token(token, line, start));
}
/**
* Scans an identifier which had started with the negative sign.
*
* @throws IOException If an I/O error occurs
*/
private void scanNegativeIdentifier () throws IOException
{
token = "-";
char c = (char) chr;
while (chr != -1 && WHITE.indexOf(c) == -1 && SPECIAL.indexOf(c) == -1)
{
token = token + (char) chr;
readChar();
c = (char) chr;
}
int start = col - token.length();
tokens.add(new Token(token, line, start));
}
/**
* Scan the input Reader and returns a list of tokens.
*
* @return a list of tokens
* @throws IOException If an I/O error occurs
*/
public List scan () throws IOException
{
line = 1;
col = 0;
boolean inComment = false;
boolean inCommentSlashStar = false;
boolean inCommentDash = false;
boolean inNegative;
tokens = new ArrayList();
readChar();
while (chr != -1)
{
char c = (char) chr;
System.out.println(c);
inNegative = false;
if (c == COMMENT_DASH)
{
readChar();
if ((char) chr == COMMENT_DASH)
{
inCommentDash = true;
}
else
{
inNegative = true;
c = (char) chr;
}
}
if (inCommentDash)
{
if (c == '\n' || c == '\r')
{
inCommentDash = false;
}
readChar();
}
else if (c == COMMENT_POUND)
{
inComment = true;
readChar();
}
else if (c == COMMENT_SLASH)
{
readChar();
if ((char) chr == COMMENT_STAR)
{
inCommentSlashStar = true;
}
}
else if (inComment || inCommentSlashStar)
{
if (c == '*')
{
readChar();
if ((char) chr == COMMENT_SLASH)
{
inCommentSlashStar = false;
}
}
else if (c == '\n' || c == '\r')
{
inComment = false;
}
readChar();
}
else if (ALFANUM.indexOf(c) >= 0)
{
if (inNegative)
{
scanNegativeIdentifier();
}
else
{
scanIdentifier();
}
}
else if (SPECIAL.indexOf(c) >= 0)
{
tokens.add(new Token("" + c, line, col));
readChar();
}
else
{
readChar();
}
}
return tokens;
}
public static void main(String[] args)
{
String sql = "select a.name,b.tile from aa a,bb b";
java.io.ByteArrayInputStream in = new ByteArrayInputStream(sql.getBytes());
BufferedReader reader = new BufferedReader(new java.io.InputStreamReader(in));
SQLScanner scan = new SQLScanner();
scan.setInput(reader);
try
{
List list = scan.scan();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}