/*
* Copyright 2004-2015 the Seasar Foundation and the Others.
*
* 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.seasar.extension.sql.parser;
import org.seasar.extension.sql.SqlTokenizer;
import org.seasar.extension.sql.TokenNotClosedRuntimeException;
/**
* {@link SqlTokenizer}の実装クラスです。
*
* @author higa
*
*/
public class SqlTokenizerImpl implements SqlTokenizer {
private String sql;
private int position = 0;
private String token;
private int tokenType = SQL;
private int nextTokenType = SQL;
private int bindVariableNum = 0;
/**
* <code>SqlTokenizerImpl</code>を作成します。
*
* @param sql
*/
public SqlTokenizerImpl(String sql) {
this.sql = sql;
}
public String getSql() {
return sql;
}
public int getPosition() {
return position;
}
public String getToken() {
return token;
}
public String getBefore() {
return sql.substring(0, position);
}
public String getAfter() {
return sql.substring(position);
}
public int getTokenType() {
return tokenType;
}
public int getNextTokenType() {
return nextTokenType;
}
public int next() {
if (position >= sql.length()) {
token = null;
tokenType = EOF;
nextTokenType = EOF;
return tokenType;
}
switch (nextTokenType) {
case SQL:
parseSql();
break;
case COMMENT:
parseComment();
break;
case ELSE:
parseElse();
break;
case BIND_VARIABLE:
parseBindVariable();
break;
default:
parseEof();
break;
}
return tokenType;
}
/**
* SQLを解析します。
*/
protected void parseSql() {
int commentStartPos = sql.indexOf("/*", position);
int commentStartPos2 = sql.indexOf("#*", position);
if (0 < commentStartPos2 && commentStartPos2 < commentStartPos) {
commentStartPos = commentStartPos2;
}
int lineCommentStartPos = sql.indexOf("--", position);
int bindVariableStartPos = sql.indexOf("?", position);
int elseCommentStartPos = -1;
int elseCommentLength = -1;
if (lineCommentStartPos >= 0) {
int skipPos = skipWhitespace(lineCommentStartPos + 2);
if (skipPos + 4 < sql.length()
&& "ELSE".equals(sql.substring(skipPos, skipPos + 4))) {
elseCommentStartPos = lineCommentStartPos;
elseCommentLength = skipPos + 4 - lineCommentStartPos;
}
}
int nextStartPos = getNextStartPos(commentStartPos,
elseCommentStartPos, bindVariableStartPos);
if (nextStartPos < 0) {
token = sql.substring(position);
nextTokenType = EOF;
position = sql.length();
tokenType = SQL;
} else {
token = sql.substring(position, nextStartPos);
tokenType = SQL;
boolean needNext = nextStartPos == position;
if (nextStartPos == commentStartPos) {
nextTokenType = COMMENT;
position = commentStartPos + 2;
} else if (nextStartPos == elseCommentStartPos) {
nextTokenType = ELSE;
position = elseCommentStartPos + elseCommentLength;
} else if (nextStartPos == bindVariableStartPos) {
nextTokenType = BIND_VARIABLE;
position = bindVariableStartPos;
}
if (needNext) {
next();
}
}
}
/**
* 次の開始位置を返します。
*
* @param commentStartPos
* コメントの開始位置
* @param elseCommentStartPos
* ELSEコメントの開始位置
* @param bindVariableStartPos
* バインド変数の開始位置
* @return 次の開始位置
*/
protected int getNextStartPos(int commentStartPos, int elseCommentStartPos,
int bindVariableStartPos) {
int nextStartPos = -1;
if (commentStartPos >= 0) {
nextStartPos = commentStartPos;
}
if (elseCommentStartPos >= 0
&& (nextStartPos < 0 || elseCommentStartPos < nextStartPos)) {
nextStartPos = elseCommentStartPos;
}
if (bindVariableStartPos >= 0
&& (nextStartPos < 0 || bindVariableStartPos < nextStartPos)) {
nextStartPos = bindVariableStartPos;
}
return nextStartPos;
}
/**
* コメントを解析します。
*/
protected void parseComment() {
int commentEndPos = sql.indexOf("*/", position);
int commentEndPos2 = sql.indexOf("*#", position);
if (0 < commentEndPos2 && commentEndPos2 < commentEndPos) {
commentEndPos = commentEndPos2;
}
if (commentEndPos < 0) {
throw new TokenNotClosedRuntimeException("*/", sql
.substring(position));
}
token = sql.substring(position, commentEndPos);
nextTokenType = SQL;
position = commentEndPos + 2;
tokenType = COMMENT;
}
/**
* バインド変数を解析します。
*/
protected void parseBindVariable() {
token = nextBindVariableName();
nextTokenType = SQL;
position += 1;
tokenType = BIND_VARIABLE;
}
/**
* ELSEを解析します。
*/
protected void parseElse() {
token = null;
nextTokenType = SQL;
tokenType = ELSE;
}
/**
* SQLの終わりを解析します。
*/
protected void parseEof() {
token = null;
tokenType = EOF;
nextTokenType = EOF;
}
/**
* 位置パラメータ用のバインド変数名を返します。
*
* @return 位置パラメータ用のバインド変数名
*/
protected String nextBindVariableName() {
return "$" + ++bindVariableNum;
}
public String skipToken() {
int index = sql.length();
char quote = position < sql.length() ? sql.charAt(position) : '\0';
boolean quoting = quote == '\'' || quote == '(';
if (quote == '(') {
quote = ')';
}
for (int i = quoting ? position + 1 : position; i < sql.length(); ++i) {
char c = sql.charAt(i);
if ((Character.isWhitespace(c) || c == ',' || c == ')' || c == '(')
&& !quoting) {
index = i;
break;
} else if (c == '/' && i + 1 < sql.length()
&& sql.charAt(i + 1) == '*') {
index = i;
break;
} else if (c == '-' && i + 1 < sql.length()
&& sql.charAt(i + 1) == '-') {
index = i;
break;
} else if (quoting && quote == '\'' && c == '\''
&& (i + 1 >= sql.length() || sql.charAt(i + 1) != '\'')) {
index = i + 1;
break;
} else if (quoting && c == quote) {
index = i + 1;
break;
}
}
token = sql.substring(position, index);
tokenType = SQL;
nextTokenType = SQL;
position = index;
return token;
}
public String skipWhitespace() {
int index = skipWhitespace(position);
token = sql.substring(position, index);
position = index;
return token;
}
private int skipWhitespace(int position) {
int index = sql.length();
for (int i = position; i < sql.length(); ++i) {
char c = sql.charAt(i);
if (!Character.isWhitespace(c)) {
index = i;
break;
}
}
return index;
}
}