| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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.apache.metamodel.jdbc.dialects; |
| |
| import java.util.List; |
| import java.util.ListIterator; |
| |
| import org.apache.metamodel.jdbc.JdbcDataContext; |
| import org.apache.metamodel.query.FilterItem; |
| import org.apache.metamodel.query.FromItem; |
| import org.apache.metamodel.query.OperatorType; |
| import org.apache.metamodel.query.Query; |
| import org.apache.metamodel.query.SelectItem; |
| import org.apache.metamodel.util.CollectionUtils; |
| |
| /** |
| * Generic query rewriter that adds syntax enhancements that are only possible |
| * to resolve just before execution time. |
| */ |
| public class DefaultQueryRewriter extends AbstractQueryRewriter { |
| |
| private static final String SPECIAL_ALIAS_CHARACTERS = "- ,.|*%()!#ยค/\\=?;:~"; |
| |
| public DefaultQueryRewriter(JdbcDataContext dataContext) { |
| super(dataContext); |
| } |
| |
| @Override |
| protected Query beforeRewrite(Query query) { |
| query = query.clone(); |
| |
| JdbcDataContext dataContext = getDataContext(); |
| if (dataContext != null) { |
| String identifierQuoteString = dataContext.getIdentifierQuoteString(); |
| if (identifierQuoteString != null) { |
| List<SelectItem> selectItems = query.getSelectClause().getItems(); |
| for (SelectItem item : selectItems) { |
| String alias = item.getAlias(); |
| if (needsQuoting(alias, identifierQuoteString)) { |
| item.setAlias(identifierQuoteString + alias + identifierQuoteString); |
| } |
| } |
| List<FromItem> fromItems = query.getFromClause().getItems(); |
| for (FromItem item : fromItems) { |
| String alias = item.getAlias(); |
| if (needsQuoting(alias, identifierQuoteString)) { |
| item.setAlias(identifierQuoteString + alias + identifierQuoteString); |
| } |
| } |
| } |
| } |
| return query; |
| } |
| |
| private boolean needsQuoting(String alias, String identifierQuoteString) { |
| boolean result = false; |
| if (alias != null && identifierQuoteString != null) { |
| if (alias.indexOf(identifierQuoteString) == -1) { |
| for (int i = 0; i < SPECIAL_ALIAS_CHARACTERS.length(); i++) { |
| char specialCharacter = SPECIAL_ALIAS_CHARACTERS.charAt(i); |
| if (alias.indexOf(specialCharacter) != -1) { |
| result = true; |
| break; |
| } |
| } |
| } |
| } |
| if (logger.isDebugEnabled()) { |
| logger.debug("needsQuoting(" + alias + "," + identifierQuoteString + ") = " + result); |
| } |
| return result; |
| } |
| |
| @Override |
| public String rewriteFilterItem(FilterItem item) { |
| Object operand = item.getOperand(); |
| if (operand != null) { |
| if (operand instanceof String) { |
| String str = (String) operand; |
| // escape single quotes |
| if (str.indexOf('\'') != -1) { |
| str = escapeQuotes(str); |
| FilterItem replacementFilterItem = new FilterItem(item.getSelectItem(), item.getOperator(), str); |
| return super.rewriteFilterItem(replacementFilterItem); |
| } |
| } else if (operand instanceof Iterable || operand.getClass().isArray()) { |
| // operand is a set of values (typically in combination with an |
| // IN operator). Each individual element must be escaped. |
| |
| assert item.getOperator() == OperatorType.IN; |
| |
| @SuppressWarnings("unchecked") |
| final List<Object> elements = (List<Object>) CollectionUtils.toList(operand); |
| |
| for (ListIterator<Object> it = elements.listIterator(); it.hasNext();) { |
| Object next = it.next(); |
| if (next == null) { |
| logger.warn("element in IN list is NULL, which isn't supported by SQL. Stripping the element from the list: {}", item); |
| it.remove(); |
| } else if (next instanceof String) { |
| String str = (String) next; |
| if (str.indexOf('\'') != -1) { |
| str = escapeQuotes(str); |
| it.set(str); |
| } |
| } |
| } |
| |
| FilterItem replacementFilterItem = new FilterItem(item.getSelectItem(), item.getOperator(), elements); |
| return super.rewriteFilterItem(replacementFilterItem); |
| } |
| } |
| return super.rewriteFilterItem(item); |
| } |
| |
| @Override |
| public boolean isFirstRowSupported() { |
| return false; |
| } |
| |
| @Override |
| public boolean isMaxRowsSupported() { |
| return false; |
| } |
| |
| @Override |
| public String escapeQuotes(String item) { |
| return item.replaceAll("\\'", "\\'\\'"); |
| } |
| } |