| package org.apache.ddlutils.platform; |
| |
| /* |
| * 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. |
| */ |
| |
| import java.util.Iterator; |
| import java.util.List; |
| |
| import org.apache.ddlutils.alteration.AddColumnChange; |
| import org.apache.ddlutils.alteration.AddPrimaryKeyChange; |
| import org.apache.ddlutils.alteration.ModelComparator; |
| import org.apache.ddlutils.alteration.TableChange; |
| import org.apache.ddlutils.alteration.TableDefinitionChangesPredicate; |
| import org.apache.ddlutils.model.Table; |
| |
| /** |
| * This is the default predicate for filtering supported table definition changes |
| * in the {@link ModelComparator}. It is also useful as the base class for platform |
| * specific implementations. |
| * |
| * @version $Revision: $ |
| */ |
| public class DefaultTableDefinitionChangesPredicate implements TableDefinitionChangesPredicate |
| { |
| /** |
| * {@inheritDoc} |
| */ |
| public boolean areSupported(Table intermediateTable, List changes) |
| { |
| for (Iterator changeIt = changes.iterator(); changeIt.hasNext();) |
| { |
| TableChange change = (TableChange)changeIt.next(); |
| |
| if (!isSupported(intermediateTable, change)) |
| { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * Checks whether the given change is suppored. |
| * |
| * @param intermediateTable The current table to which this change would be applied |
| * @param change The table change |
| * @return <code>true</code> if the change is supported |
| */ |
| protected boolean isSupported(Table intermediateTable, TableChange change) |
| { |
| if (change instanceof AddColumnChange) |
| { |
| AddColumnChange addColumnChange = (AddColumnChange)change; |
| |
| return addColumnChange.isAtEnd() && |
| (!addColumnChange.getNewColumn().isRequired() || |
| (addColumnChange.getNewColumn().getDefaultValue() != null) || |
| addColumnChange.getNewColumn().isAutoIncrement()); |
| } |
| else if (change instanceof AddPrimaryKeyChange) |
| { |
| return true; |
| } |
| else |
| { |
| return false; |
| } |
| } |
| } |