DATAJDBC-106 - Support to specify a database object names using annotations.

@Table and @Column annotation added for configuring table and column names.

Original pull request: #65.

src/main/java/org/springframework/data/jdbc/mapping/model/Column.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2018 the original author or 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
+ *
+ *      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.springframework.data.jdbc.mapping.model;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * The annotation to configure a mapping database column.
+ *
+ * @author Kazuki Shimizu
+ * @since 1.0
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.FIELD, ElementType.METHOD})
+@Documented
+public @interface Column {
+
+	/**
+	 * The mapping column name.
+	 */
+	String value();
+
+}

src/main/java/org/springframework/data/jdbc/mapping/model/NamingStrategy.java

@@ -15,6 +15,10 @@
  */
 package org.springframework.data.jdbc.mapping.model;
 
+import org.springframework.core.annotation.AnnotatedElementUtils;
+
+import java.util.Optional;
+
 /**
  * Interface and default implementation of a naming strategy. Defaults to no schema, table name based on {@link Class}
  * and column name based on {@link JdbcPersistentProperty}.
@@ -45,17 +49,23 @@ public interface NamingStrategy {
 	}
 
 	/**
-	 * Look up the {@link Class}'s simple name.
+	 * Look up the {@link Class}'s simple name or {@link Table#value()}.
 	 */
 	default String getTableName(Class<?> type) {
-		return type.getSimpleName();
+		Table table = AnnotatedElementUtils.findMergedAnnotation(type, Table.class);
+		return Optional.ofNullable(table)//
+			.map(Table::value)//
+			.orElse(type.getSimpleName());
 	}
 
 	/**
-	 * Look up the {@link JdbcPersistentProperty}'s name.
+	 * Look up the {@link JdbcPersistentProperty}'s name or {@link Column#value()}.
 	 */
 	default String getColumnName(JdbcPersistentProperty property) {
-		return property.getName();
+		Column column = property.findAnnotation(Column.class);
+		return Optional.ofNullable(column)//
+			.map(Column::value)//
+			.orElse(property.getName());
 	}
 
 	default String getQualifiedTableName(Class<?> type) {

src/main/java/org/springframework/data/jdbc/mapping/model/Table.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2018 the original author or 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
+ *
+ *      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.springframework.data.jdbc.mapping.model;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Inherited;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * The annotation to configure a mapping database table.
+ *
+ * @author Kazuki Shimizu
+ * @since 1.0
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+@Documented
+@Inherited
+public @interface Table {
+
+	/**
+	 * The mapping table name.
+	 */
+	String value();
+
+}

src/test/java/org/springframework/data/jdbc/mapping/model/NamingStrategyUnitTests.java

@@ -0,0 +1,122 @@
+/*
+ * Copyright 2018 the original author or 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
+ *
+ *      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.springframework.data.jdbc.mapping.model;
+
+import org.junit.Test;
+import org.springframework.data.annotation.Id;
+import org.springframework.jdbc.core.namedparam.NamedParameterJdbcOperations;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Unit tests for the {@link NamingStrategy}.
+ *
+ * @author Kazuki Shimizu
+ */
+public class NamingStrategyUnitTests {
+
+	private final NamingStrategy target = NamingStrategy.INSTANCE;
+	private final JdbcMappingContext context = new JdbcMappingContext(target, mock(NamedParameterJdbcOperations.class), mock(ConversionCustomizer.class));
+	private final JdbcPersistentEntity<?> persistentEntity = context.getRequiredPersistentEntity(DummyEntity.class);
+
+	@Test
+	public void getTableName() {
+		assertThat(target.getTableName(persistentEntity.getType()))
+				.isEqualTo("DummyEntity");
+		assertThat(target.getTableName(DummySubEntity.class))
+			.isEqualTo("dummy_sub_entity"); // DATAJDBC-106
+	}
+
+	@Test // DATAJDBC-106
+	public void getTableNameWithTableAnnotation() {
+		assertThat(target.getTableName(DummySubEntity.class))
+			.isEqualTo("dummy_sub_entity");
+	}
+
+	@Test
+	public void getColumnName() {
+		assertThat(target.getColumnName(persistentEntity.getPersistentProperty("id")))
+				.isEqualTo("id");
+		assertThat(target.getColumnName(persistentEntity.getPersistentProperty("createdAt")))
+				.isEqualTo("createdAt");
+		assertThat(target.getColumnName(persistentEntity.getPersistentProperty("dummySubEntities")))
+				.isEqualTo("dummySubEntities");
+	}
+
+	@Test // DATAJDBC-106
+	public void getColumnNameWithColumnAnnotation() {
+		assertThat(target.getColumnName(persistentEntity.getPersistentProperty("name")))
+			.isEqualTo("dummy_name");
+		assertThat(target.getColumnName(persistentEntity.getPersistentProperty("lastUpdatedAt")))
+			.isEqualTo("dummy_last_updated_at");
+	}
+
+	@Test
+	public void getReverseColumnName() {
+		assertThat(target.getReverseColumnName(persistentEntity.getPersistentProperty("dummySubEntities")))
+				.isEqualTo("DummyEntity");
+	}
+
+	@Test
+	public void getKeyColumn() {
+		assertThat(target.getKeyColumn(persistentEntity.getPersistentProperty("dummySubEntities")))
+				.isEqualTo("DummyEntity_key");
+	}
+
+	@Test
+	public void getSchema() {
+		assertThat(target.getSchema())
+				.isEmpty();
+	}
+
+	@Test
+	public void getQualifiedTableName() {
+		assertThat(target.getQualifiedTableName(persistentEntity.getType()))
+				.isEqualTo("DummyEntity");
+
+		NamingStrategy strategy = new NamingStrategy() {
+			@Override
+			public String getSchema() {
+				return "schema";
+			}
+		};
+		assertThat(strategy.getQualifiedTableName(persistentEntity.getType()))
+			.isEqualTo("schema.DummyEntity");
+	}
+
+	private static class DummyEntity {
+		@Id
+		private int id;
+		@Column("dummy_name")
+		private String name;
+		private LocalDateTime createdAt;
+		private LocalDateTime lastUpdatedAt;
+		private List<DummySubEntity> dummySubEntities;
+		@Column("dummy_last_updated_at")
+		public LocalDateTime getLastUpdatedAt() {
+			return LocalDateTime.now();
+		}
+	}
+
+	@Table("dummy_sub_entity")
+	private static class DummySubEntity {
+	}
+
+}