package jef.database.routing.jdbc;
import java.io.IOException;
import java.io.StringReader;
import java.sql.SQLException;
import java.util.regex.Pattern;
import jef.tools.StringUtils;
public class SqlTypeParser {
/**
* 用于判断是否是一个select ... for update的sql
*/
private static final Pattern SELECT_FOR_UPDATE_PATTERN = Pattern.compile(
"^select\\s+.*\\s+for\\s+update.*$", Pattern.CASE_INSENSITIVE);
public static boolean isQuerySql(String sql) throws SQLException {
SqlType sqlType = getSqlType(sql);
if (sqlType == SqlType.SELECT || sqlType == SqlType.SELECT_FOR_UPDATE
|| sqlType == SqlType.SHOW || sqlType == SqlType.DUMP
|| sqlType == SqlType.DEBUG || sqlType == SqlType.EXPLAIN) {
return true;
} else if (sqlType == SqlType.INSERT || sqlType == SqlType.UPDATE
|| sqlType == SqlType.DELETE || sqlType == SqlType.REPLACE
|| sqlType == SqlType.TRUNCATE || sqlType == SqlType.CREATE
|| sqlType == SqlType.DROP || sqlType == SqlType.LOAD
|| sqlType == SqlType.MERGE || sqlType == SqlType.ALTER
|| sqlType == SqlType.RENAME) {
return false;
} else {
return throwNotSupportSqlTypeException();
}
}
/**
* 获得SQL语句种类
*
* @param sql
* SQL语句
* @throws SQLException
* 当SQL语句不是SELECT、INSERT、UPDATE、DELETE语句时，抛出异常。
*/
public static SqlType getSqlType(String sql) throws SQLException {
// #bug 2011-11-24,modify by junyu,先不走缓存，否则sql变化巨大，缓存换入换出太多，gc太明显
// SqlType sqlType = globalCache.getSqlType(sql);
// if (sqlType == null) {
SqlType sqlType = null;
// #bug 2011-12-8,modify by junyu ,this code use huge cpu resource,and
// most
// sql have no comment,so first simple look for there whether have the
// comment
String noCommentsSql = sql;
if (sql.contains("/*")) {
noCommentsSql = stripComments(sql, "'\"", "'\"", true,
false, true, true).trim();
}
if (StringUtils.startsWithIgnoreCaseAndWs(noCommentsSql, "select")) {
// #bug 2011-12-9,this select-for-update regex has low
// performance,so
// first judge this sql whether have ' for ' string.
if (noCommentsSql.toLowerCase().contains(" for ")
&& SELECT_FOR_UPDATE_PATTERN.matcher(noCommentsSql)
.matches()) {
sqlType = SqlType.SELECT_FOR_UPDATE;
} else {
sqlType = SqlType.SELECT;
}
} else if (StringUtils.startsWithIgnoreCaseAndWs(noCommentsSql,
"insert")) {
sqlType = SqlType.INSERT;
} else if (StringUtils.startsWithIgnoreCaseAndWs(noCommentsSql,
"update")) {
sqlType = SqlType.UPDATE;
} else if (StringUtils.startsWithIgnoreCaseAndWs(noCommentsSql,
"delete")) {
sqlType = SqlType.DELETE;
} else if (StringUtils.startsWithIgnoreCaseAndWs(noCommentsSql, "show")) {
sqlType = SqlType.SHOW;
} else if (StringUtils.startsWithIgnoreCaseAndWs(noCommentsSql,
"replace")) {
sqlType = SqlType.REPLACE;
} else if (StringUtils.startsWithIgnoreCaseAndWs(noCommentsSql,
"truncate")) {
sqlType = SqlType.TRUNCATE;
} else if (StringUtils.startsWithIgnoreCaseAndWs(noCommentsSql,
"create")) {
sqlType = SqlType.CREATE;
} else if (StringUtils.startsWithIgnoreCaseAndWs(noCommentsSql, "drop")) {
sqlType = SqlType.DROP;
} else if (StringUtils.startsWithIgnoreCaseAndWs(noCommentsSql, "load")) {
sqlType = SqlType.LOAD;
} else if (StringUtils
.startsWithIgnoreCaseAndWs(noCommentsSql, "merge")) {
sqlType = SqlType.MERGE;
} else if (StringUtils
.startsWithIgnoreCaseAndWs(noCommentsSql, "alter")) {
sqlType = SqlType.ALTER;
} else if (StringUtils.startsWithIgnoreCaseAndWs(noCommentsSql,
"rename")) {
sqlType = SqlType.RENAME;
} else if (StringUtils.startsWithIgnoreCaseAndWs(noCommentsSql,
"dump")) {
sqlType = SqlType.DUMP;
} else if (StringUtils.startsWithIgnoreCaseAndWs(noCommentsSql,
"debug")) {
sqlType = SqlType.DEBUG;
} else if (StringUtils.startsWithIgnoreCaseAndWs(noCommentsSql,
"explain")) {
sqlType = SqlType.EXPLAIN;
} else {
throwNotSupportSqlTypeException();
}
return sqlType;
}
public static boolean throwNotSupportSqlTypeException() throws SQLException{
throw new SQLException(
"only select, insert, update, delete, replace, show, truncate, create, drop, load, merge, dump sql is supported");
}
/**
* Returns the given string, with comments removed
*
* @param src
* the source string
* @param stringOpens
* characters which delimit the "open" of a string
* @param stringCloses
* characters which delimit the "close" of a string, in
* counterpart order to <code>stringOpens</code>
* @param slashStarComments
* strip slash-star type "C" style comments
* @param slashSlashComments
* strip slash-slash C++ style comments to end-of-line
* @param hashComments
* strip #-style comments to end-of-line
* @param dashDashComments
* strip "--" style comments to end-of-line
* @return the input string with all comment-delimited data removed
*/
private static String stripComments(String src, String stringOpens,
String stringCloses, boolean slashStarComments,
boolean slashSlashComments, boolean hashComments,
boolean dashDashComments) {
if (src == null) {
return null;
}
StringBuffer buf = new StringBuffer(src.length());
// It's just more natural to deal with this as a stream
// when parsing..This code is currently only called when
// parsing the kind of metadata that developers are strongly
// recommended to cache anyways, so we're not worried
// about the _1_ extra object allocation if it cleans
// up the code
StringReader sourceReader = new StringReader(src);
int contextMarker = Character.MIN_VALUE;
boolean escaped = false;
int markerTypeFound = -1;
int ind = 0;
int currentChar = 0;
try {
while ((currentChar = sourceReader.read()) != -1) {
// if (false && currentChar == '\\') {
// escaped = !escaped;
// } else
if (markerTypeFound != -1 && currentChar == stringCloses.charAt(markerTypeFound)
&& !escaped) {
contextMarker = Character.MIN_VALUE;
markerTypeFound = -1;
} else if ((ind = stringOpens.indexOf(currentChar)) != -1
&& !escaped && contextMarker == Character.MIN_VALUE) {
markerTypeFound = ind;
contextMarker = currentChar;
}
if (contextMarker == Character.MIN_VALUE && currentChar == '/'
&& (slashSlashComments || slashStarComments)) {
currentChar = sourceReader.read();
if (currentChar == '*' && slashStarComments) {
int prevChar = 0;
while ((currentChar = sourceReader.read()) != '/'
|| prevChar != '*') {
if (currentChar == '\r') {
currentChar = sourceReader.read();
if (currentChar == '\n') {
currentChar = sourceReader.read();
}
} else {
if (currentChar == '\n') {
currentChar = sourceReader.read();
}
}
if (currentChar < 0)
break;
prevChar = currentChar;
}
continue;
} else if (currentChar == '/' && slashSlashComments) {
while ((currentChar = sourceReader.read()) != '\n'
&& currentChar != '\r' && currentChar >= 0)
;
}
} else if (contextMarker == Character.MIN_VALUE
&& currentChar == '#' && hashComments) {
// Slurp up everything until the newline
while ((currentChar = sourceReader.read()) != '\n'
&& currentChar != '\r' && currentChar >= 0)
;
} else if (contextMarker == Character.MIN_VALUE
&& currentChar == '-' && dashDashComments) {
currentChar = sourceReader.read();
if (currentChar == -1 || currentChar != '-') {
buf.append('-');
if (currentChar != -1) {
buf.append(currentChar);
}
continue;
}
// Slurp up everything until the newline
while ((currentChar = sourceReader.read()) != '\n'
&& currentChar != '\r' && currentChar >= 0)
;
}
if (currentChar != -1) {
buf.append((char) currentChar);
}
}
} catch (IOException ioEx) {
// we'll never see this from a StringReader
}
return buf.toString();
}
}