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1   /*
2    *    Copyright 2016-2025 the original author or authors.
3    *
4    *    Licensed under the Apache License, Version 2.0 (the "License");
5    *    you may not use this file except in compliance with the License.
6    *    You may obtain a copy of the License at
7    *
8    *       https://www.apache.org/licenses/LICENSE-2.0
9    *
10   *    Unless required by applicable law or agreed to in writing, software
11   *    distributed under the License is distributed on an "AS IS" BASIS,
12   *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   *    See the License for the specific language governing permissions and
14   *    limitations under the License.
15   */
16  package org.mybatis.dynamic.sql.render;
17  
18  import java.util.Map;
19  import java.util.Optional;
20  
21  import org.mybatis.dynamic.sql.SqlTable;
22  
23  /**
24   * Returns the alias for a table if specified, or the table name itself.
25   * This is useful for join rendering when we always want to have an alias for the table.
26   *
27   * @author Jeff Butler
28   */
29  public class GuaranteedTableAliasCalculator extends ExplicitTableAliasCalculator {
30  
31      private GuaranteedTableAliasCalculator(Map<SqlTable, String> aliases) {
32          super(aliases);
33      }
34  
35      @Override
36      public Optional<String> aliasForColumn(SqlTable table) {
37          Optional<String> alias = super.aliasForColumn(table);
38          if (alias.isPresent()) {
39              return alias;
40          } else {
41              return Optional.of(table.tableName());
42          }
43      }
44  
45      public static TableAliasCalculator of(Map<SqlTable, String> aliases) {
46          return new GuaranteedTableAliasCalculator(aliases);
47      }
48  }