/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Middleware LLC.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* 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 Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*
*/
package org.hibernate.sql;
import java.util.HashSet;
import java.util.StringTokenizer;
import org.hibernate.dialect.Dialect;
import org.hibernate.dialect.function.SQLFunction;
import org.hibernate.dialect.function.SQLFunctionRegistry;
import org.hibernate.util.StringHelper;
import org.hibernate.sql.ordering.antlr.ColumnMapper;
import org.hibernate.sql.ordering.antlr.TranslationContext;
import org.hibernate.sql.ordering.antlr.OrderByFragmentTranslator;
import org.hibernate.engine.SessionFactoryImplementor;
/**
* Parses SQL fragments specified in mapping documents
*
* @author Gavin King
*/
public final class Template {
private static final java.util.Set KEYWORDS = new HashSet();
private static final java.util.Set BEFORE_TABLE_KEYWORDS = new HashSet();
private static final java.util.Set FUNCTION_KEYWORDS = new HashSet();
static {
KEYWORDS.add("and");
KEYWORDS.add("or");
KEYWORDS.add("not");
KEYWORDS.add("like");
KEYWORDS.add("is");
KEYWORDS.add("in");
KEYWORDS.add("between");
KEYWORDS.add("null");
KEYWORDS.add("select");
KEYWORDS.add("distinct");
KEYWORDS.add("from");
KEYWORDS.add("join");
KEYWORDS.add("inner");
KEYWORDS.add("outer");
KEYWORDS.add("left");
KEYWORDS.add("right");
KEYWORDS.add("on");
KEYWORDS.add("where");
KEYWORDS.add("having");
KEYWORDS.add("group");
KEYWORDS.add("order");
KEYWORDS.add("by");
KEYWORDS.add("desc");
KEYWORDS.add("asc");
KEYWORDS.add("limit");
KEYWORDS.add("any");
KEYWORDS.add("some");
KEYWORDS.add("exists");
KEYWORDS.add("all");
KEYWORDS.add("union");
KEYWORDS.add("minus");
BEFORE_TABLE_KEYWORDS.add("from");
BEFORE_TABLE_KEYWORDS.add("join");
FUNCTION_KEYWORDS.add("as");
FUNCTION_KEYWORDS.add("leading");
FUNCTION_KEYWORDS.add("trailing");
FUNCTION_KEYWORDS.add("from");
FUNCTION_KEYWORDS.add("case");
FUNCTION_KEYWORDS.add("when");
FUNCTION_KEYWORDS.add("then");
FUNCTION_KEYWORDS.add("else");
FUNCTION_KEYWORDS.add("end");
}
public static final String TEMPLATE = "$PlaceHolder$";
private Template() {}
public static String renderWhereStringTemplate(String sqlWhereString, Dialect dialect, SQLFunctionRegistry functionRegistry) {
return renderWhereStringTemplate(sqlWhereString, TEMPLATE, dialect, functionRegistry);
}
/**
* Same functionality as {@link #renderWhereStringTemplate(String, String, Dialect, SQLFunctionRegistry)},
* except that a SQLFunctionRegistry is not provided (i.e., only the dialect-defined functions are
* considered). This is only intended for use by the annotations project until the
* many-to-many/map-key-from-target-table feature is pulled into core.
*
* @deprecated Only intended for annotations usage; use {@link #renderWhereStringTemplate(String, String, Dialect, SQLFunctionRegistry)} instead
*/
public static String renderWhereStringTemplate(String sqlWhereString, String placeholder, Dialect dialect) {
return renderWhereStringTemplate( sqlWhereString, placeholder, dialect, new SQLFunctionRegistry( dialect, java.util.Collections.EMPTY_MAP ) );
}
/**
* Takes the where condition provided in the mapping attribute and interpolates the alias.
* Handles subselects, quoted identifiers, quoted strings, expressions, SQL functions,
* named parameters.
*
* @param sqlWhereString The string into which to interpolate the placeholder value
* @param placeholder The value to be interpolated into the the sqlWhereString
* @param dialect The dialect to apply
* @param functionRegistry The registry of all sql functions
* @return The rendered sql fragment
*/
public static String renderWhereStringTemplate(String sqlWhereString, String placeholder, Dialect dialect, SQLFunctionRegistry functionRegistry ) {
//TODO: make this a bit nicer
String symbols = new StringBuffer()
.append("=><!+-*/()',|&`")
.append(StringHelper.WHITESPACE)
.append( dialect.openQuote() )
.append( dialect.closeQuote() )
.toString();
StringTokenizer tokens = new StringTokenizer(sqlWhereString, symbols, true);
StringBuffer result = new StringBuffer();
boolean quoted = false;
boolean quotedIdentifier = false;
boolean beforeTable = false;
boolean inFromClause = false;
boolean afterFromTable = false;
boolean hasMore = tokens.hasMoreTokens();
String nextToken = hasMore ? tokens.nextToken() : null;
while (hasMore) {
String token = nextToken;
String lcToken = token.toLowerCase();
hasMore = tokens.hasMoreTokens();
nextToken = hasMore ? tokens.nextToken() : null;
boolean isQuoteCharacter = false;
if ( !quotedIdentifier && "'".equals(token) ) {
quoted = !quoted;
isQuoteCharacter = true;
}
if ( !quoted ) {
boolean isOpenQuote;
if ( "`".equals(token) ) {
isOpenQuote = !quotedIdentifier;
token = lcToken = isOpenQuote ?
new Character( dialect.openQuote() ).toString() :
new Character( dialect.closeQuote() ).toString();
quotedIdentifier = isOpenQuote;
isQuoteCharacter = true;
}
else if ( !quotedIdentifier && ( dialect.openQuote()==token.charAt(0) ) ) {
isOpenQuote = true;
quotedIdentifier = true;
isQuoteCharacter = true;
}
else if ( quotedIdentifier && ( dialect.closeQuote()==token.charAt(0) ) ) {
quotedIdentifier = false;
isQuoteCharacter = true;
isOpenQuote = false;
}
else {
isOpenQuote = false;
}
if (isOpenQuote) {
result.append(placeholder).append('.');
}
}
boolean quotedOrWhitespace = quoted ||
quotedIdentifier ||
isQuoteCharacter ||
Character.isWhitespace( token.charAt(0) );
if (quotedOrWhitespace) {
result.append(token);
}
else if (beforeTable) {
result.append(token);
beforeTable = false;
afterFromTable = true;
}
else if (afterFromTable) {
if ( !"as".equals(lcToken) ) afterFromTable = false;
result.append(token);
}
else if ( isNamedParameter(token) ) {
result.append(token);
}
else if (
isIdentifier(token, dialect) &&
!isFunctionOrKeyword(lcToken, nextToken, dialect , functionRegistry)
) {
result.append(placeholder)
.append('.')
.append( dialect.quote(token) );
}
else {
if ( BEFORE_TABLE_KEYWORDS.contains(lcToken) ) {
beforeTable = true;
inFromClause = true;
}
else if ( inFromClause && ",".equals(lcToken) ) {
beforeTable = true;
}
result.append(token);
}
if ( //Yuck:
inFromClause &&
KEYWORDS.contains(lcToken) && //"as" is not in KEYWORDS
!BEFORE_TABLE_KEYWORDS.contains(lcToken)
) {
inFromClause = false;
}
}
return result.toString();
}
public static class NoOpColumnMapper implements ColumnMapper {
public static final NoOpColumnMapper INSTANCE = new NoOpColumnMapper();
public String[] map(String reference) {
return new String[] { reference };
}
}
/**
* Performs order-by template rendering without {@link ColumnMapper column mapping}. An <tt>ORDER BY</tt> template
* has all column references "qualified" with a placeholder identified by {@link Template#TEMPLATE}
*
* @param orderByFragment The order-by fragment to render.
* @param dialect The SQL dialect being used.
* @param functionRegistry The SQL function registry
*
* @return The rendered <tt>ORDER BY</tt> template.
*
* @see #renderOrderByStringTemplate(String,ColumnMapper,SessionFactoryImplementor,Dialect,SQLFunctionRegistry)
*/
public static String renderOrderByStringTemplate(
String orderByFragment,
Dialect dialect,
SQLFunctionRegistry functionRegistry) {
return renderOrderByStringTemplate(
orderByFragment,
NoOpColumnMapper.INSTANCE,
null,
dialect,
functionRegistry
);
}
/**
* Performs order-by template rendering allowing {@link ColumnMapper column mapping}. An <tt>ORDER BY</tt> template
* has all column references "qualified" with a placeholder identified by {@link Template#TEMPLATE} which can later
* be used to easily inject the SQL alias.
*
* @param orderByFragment The order-by fragment to render.
* @param columnMapper The column mapping strategy to use.
* @param sessionFactory The session factory.
* @param dialect The SQL dialect being used.
* @param functionRegistry The SQL function registry
*
* @return The rendered <tt>ORDER BY</tt> template.
*/
public static String renderOrderByStringTemplate(
String orderByFragment,
final ColumnMapper columnMapper,
final SessionFactoryImplementor sessionFactory,
final Dialect dialect,
final SQLFunctionRegistry functionRegistry) {
TranslationContext context = new TranslationContext() {
public SessionFactoryImplementor getSessionFactory() {
return sessionFactory;
}
public Dialect getDialect() {
return dialect;
}
public SQLFunctionRegistry getSqlFunctionRegistry() {
return functionRegistry;
}
public ColumnMapper getColumnMapper() {
return columnMapper;
}
};
OrderByFragmentTranslator translator = new OrderByFragmentTranslator( context );
return translator.render( orderByFragment );
}
private static boolean isNamedParameter(String token) {
return token.startsWith(":");
}
private static boolean isFunctionOrKeyword(String lcToken, String nextToken, Dialect dialect, SQLFunctionRegistry functionRegistry) {
return "(".equals(nextToken) ||
KEYWORDS.contains(lcToken) ||
isFunction(lcToken, nextToken, functionRegistry ) ||
dialect.getKeywords().contains(lcToken) ||
FUNCTION_KEYWORDS.contains(lcToken);
}
private static boolean isFunction(String lcToken, String nextToken, SQLFunctionRegistry functionRegistry) {
// checking for "(" is currently redundant because it is checked before getting here;
// doing the check anyhow, in case that earlier check goes away;
if ( "(".equals( nextToken ) ) {
return true;
}
SQLFunction function = functionRegistry.findSQLFunction(lcToken);
if ( function == null ) {
// lcToken does not refer to a function
return false;
}
// if function.hasParenthesesIfNoArguments() is true, then assume
// lcToken is not a function (since it is not followed by '(')
return ! function.hasParenthesesIfNoArguments();
}
private static boolean isIdentifier(String token, Dialect dialect) {
return token.charAt(0)=='`' || ( //allow any identifier quoted with backtick
Character.isLetter( token.charAt(0) ) && //only recognizes identifiers beginning with a letter
token.indexOf('.') < 0
);
}
}