Add DuplicateColumnHandler interface and its implementations to make …

…DuplicateColumnException optional

doma-core/src/main/java/org/seasar/doma/internal/jdbc/command/EntityProvider.java

@@ -27,7 +27,12 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import org.seasar.doma.jdbc.*;
+import org.seasar.doma.jdbc.DuplicateColumnHandler;
+import org.seasar.doma.jdbc.JdbcMappingVisitor;
+import org.seasar.doma.jdbc.Naming;
+import org.seasar.doma.jdbc.ResultMappingException;
+import org.seasar.doma.jdbc.Sql;
+import org.seasar.doma.jdbc.UnknownColumnHandler;
 import org.seasar.doma.jdbc.entity.EntityPropertyType;
 import org.seasar.doma.jdbc.entity.EntityType;
 import org.seasar.doma.jdbc.entity.Property;
@@ -45,6 +50,8 @@ public class EntityProvider<ENTITY> extends AbstractObjectProvider<ENTITY> {
 
   protected final UnknownColumnHandler unknownColumnHandler;
 
+  protected final DuplicateColumnHandler duplicateColumnHandler;
+
   protected Map<Integer, EntityPropertyType<ENTITY, ?>> indexMap;
 
   public EntityProvider(EntityType<ENTITY> entityType, Query query, boolean resultMappingEnsured) {
@@ -54,6 +61,7 @@ public EntityProvider(EntityType<ENTITY> entityType, Query query, boolean result
     this.resultMappingEnsured = resultMappingEnsured;
     this.jdbcMappingVisitor = query.getConfig().getDialect().getJdbcMappingVisitor();
     this.unknownColumnHandler = query.getConfig().getUnknownColumnHandler();
+    this.duplicateColumnHandler = query.getConfig().getDuplicateColumnHandler();
   }
 
   @Override
@@ -93,12 +101,7 @@ protected ENTITY build(ResultSet resultSet) throws SQLException {
       String columnName = resultSetMeta.getColumnLabel(i);
       String lowerCaseColumnName = columnName.toLowerCase();
       if (!seenColumnNames.add(lowerCaseColumnName)) {
-        throw new DuplicateColumnException(
-            query.getConfig().getExceptionSqlLogType(),
-            columnName,
-            query.getSql().getRawSql(),
-            query.getSql().getFormattedSql(),
-            query.getSql().getSqlFilePath());
+        duplicateColumnHandler.handle(query, columnName);
       }
       EntityPropertyType<ENTITY, ?> propertyType = columnNameMap.get(lowerCaseColumnName);
       if (propertyType == null) {

doma-core/src/main/java/org/seasar/doma/jdbc/Config.java

@@ -141,6 +141,15 @@ default UnknownColumnHandler getUnknownColumnHandler() {
     return ConfigSupport.defaultUnknownColumnHandler;
   }
 
+  /**
+   * Returns the duplicate column handler.
+   *
+   * @return the duplicate column handler
+   */
+  default DuplicateColumnHandler getDuplicateColumnHandler() {
+    return ConfigSupport.defaultDuplicateColumnHandler;
+  }
+
   /**
    * Returns the naming convention controller.
    *

doma-core/src/main/java/org/seasar/doma/jdbc/ConfigSupport.java

@@ -40,6 +40,9 @@ public final class ConfigSupport {
   public static final UnknownColumnHandler defaultUnknownColumnHandler =
       new UnknownColumnHandler() {};
 
+  public static final DuplicateColumnHandler defaultDuplicateColumnHandler =
+      new DuplicateColumnHandler() {};
+
   public static final Naming defaultNaming = Naming.DEFAULT;
 
   public static final MapKeyNaming defaultMapKeyNaming = new MapKeyNaming() {};

doma-core/src/main/java/org/seasar/doma/jdbc/DuplicateColumnHandler.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright Doma Authors
+ *
+ * Licensed 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
+ *
+ *     https://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.seasar.doma.jdbc;
+
+import org.seasar.doma.jdbc.query.Query;
+
+/** A handler for the column that is duplicated in a result set. */
+public interface DuplicateColumnHandler {
+
+  /**
+   * Handles the duplicate column.
+   *
+   * @param query the query
+   * @param duplicateColumnName the name of the unknown column
+   * @throws DuplicateColumnException if this handler does not allow the duplicate column
+   */
+  default void handle(Query query, String duplicateColumnName) {
+    Sql<?> sql = query.getSql();
+    throw new DuplicateColumnException(
+        query.getConfig().getExceptionSqlLogType(),
+        duplicateColumnName,
+        sql.getRawSql(),
+        sql.getFormattedSql(),
+        sql.getSqlFilePath());
+  }
+}

doma-core/src/test/java/org/seasar/doma/internal/jdbc/command/EntityProviderTest.java

@@ -23,6 +23,7 @@
 import example.entity._Emp;
 import java.lang.reflect.Method;
 import java.math.BigDecimal;
+import java.sql.SQLException;
 import java.util.Collections;
 import org.junit.jupiter.api.Test;
 import org.seasar.doma.FetchType;
@@ -107,7 +108,7 @@ public void testGetEntity_EmptyUnknownColumnHandler() throws Exception {
   }
 
   @Test
-  public void testCreateIndexMap_DuplicateColumnName() throws Exception {
+  public void testCreateIndexMap_DuplicateColumnNameException() {
     MockResultSetMetaData metaData = new MockResultSetMetaData();
     metaData.columns.add(new ColumnMetaData("id"));
     metaData.columns.add(new ColumnMetaData("name"));
@@ -119,10 +120,31 @@ public void testCreateIndexMap_DuplicateColumnName() throws Exception {
         new EntityProvider<>(entityType, new MySelectQuery(new MockConfig()), false);
 
     assertThrows(
-        DuplicateColumnException.class,
-        () -> {
-          provider.createIndexMap(metaData, entityType);
-        });
+        DuplicateColumnException.class, () -> provider.createIndexMap(metaData, entityType));
+  }
+
+  @Test
+  public void testCreateIndexMap_EmptyDuplicateColumnHandler() throws SQLException {
+    MockResultSetMetaData metaData = new MockResultSetMetaData();
+    metaData.columns.add(new ColumnMetaData("id"));
+    metaData.columns.add(new ColumnMetaData("name"));
+    metaData.columns.add(new ColumnMetaData("name")); // Duplicate column name
+    metaData.columns.add(new ColumnMetaData("version"));
+    MockResultSet resultSet = new MockResultSet(metaData);
+    resultSet.rows.add(new RowData(1, "aaa", "bbb", 100));
+    resultSet.next();
+
+    _Emp entityType = _Emp.getSingletonInternal();
+    EntityProvider<Emp> provider =
+        new EntityProvider<>(
+            entityType, new MySelectQuery(new EmptyDuplicateColumnHandlerConfig()), false);
+
+    provider.createIndexMap(metaData, entityType);
+    Emp emp = provider.get(resultSet);
+
+    assertEquals(1, emp.getId());
+    assertEquals("bbb", emp.getName());
+    assertEquals(100, emp.getVersion());
   }
 
   protected static class MySelectQuery implements SelectQuery {
@@ -227,4 +249,16 @@ public UnknownColumnHandler getUnknownColumnHandler() {
       return new EmptyUnknownColumnHandler();
     }
   }
+
+  protected static class EmptyDuplicateColumnHandler implements DuplicateColumnHandler {
+    @Override
+    public void handle(Query query, String unknownColumnName) {}
+  }
+
+  protected static class EmptyDuplicateColumnHandlerConfig extends MockConfig {
+    @Override
+    public DuplicateColumnHandler getDuplicateColumnHandler() {
+      return new EmptyDuplicateColumnHandler();
+    }
+  }
 }