Add SpEL support for @Table, @Column and @MappedCollection

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/mapping/JdbcMappingContext.java

@@ -81,7 +81,7 @@ protected RelationalPersistentProperty createPersistentProperty(Property propert
 			RelationalPersistentEntity<?> owner, SimpleTypeHolder simpleTypeHolder) {
 		BasicJdbcPersistentProperty persistentProperty = new BasicJdbcPersistentProperty(property, owner, simpleTypeHolder,
 				this.getNamingStrategy());
-		persistentProperty.setForceQuote(isForceQuote());
+		applyDefaults(persistentProperty);
 		return persistentProperty;
 	}
 

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/BasicRelationalPersistentEntity.java

@@ -0,0 +1,161 @@
+/*
+ * Copyright 2017-2023 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
+ *
+ *      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.springframework.data.relational.core.mapping;
+
+import java.util.Optional;
+
+import org.springframework.data.mapping.model.BasicPersistentEntity;
+import org.springframework.data.relational.core.sql.SqlIdentifier;
+import org.springframework.data.util.Lazy;
+import org.springframework.data.util.TypeInformation;
+import org.springframework.expression.Expression;
+import org.springframework.expression.ParserContext;
+import org.springframework.expression.common.LiteralExpression;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.lang.Nullable;
+import org.springframework.util.StringUtils;
+
+/**
+ * SQL-specific {@link RelationalPersistentEntity} implementation that adds SQL-specific meta-data such as the table and
+ * schema name.
+ *
+ * @author Jens Schauder
+ * @author Greg Turnquist
+ * @author Bastian Wilhelm
+ * @author Mikhail Polivakha
+ * @author Kurt Niemi
+ */
+class BasicRelationalPersistentEntity<T> extends BasicPersistentEntity<T, RelationalPersistentProperty>
+		implements RelationalPersistentEntity<T> {
+
+	private static final SpelExpressionParser PARSER = new SpelExpressionParser();
+
+	private final NamingStrategy namingStrategy;
+
+	private final Lazy<SqlIdentifier> tableName;
+	private final @Nullable Expression tableNameExpression;
+
+	private final Lazy<Optional<SqlIdentifier>> schemaName;
+	private final ExpressionEvaluator expressionEvaluator;
+	private boolean forceQuote = true;
+
+	/**
+	 * Creates a new {@link BasicRelationalPersistentEntity} for the given {@link TypeInformation}.
+	 *
+	 * @param information must not be {@literal null}.
+	 */
+	BasicRelationalPersistentEntity(TypeInformation<T> information, NamingStrategy namingStrategy,
+			ExpressionEvaluator expressionEvaluator) {
+
+		super(information);
+
+		this.namingStrategy = namingStrategy;
+		this.expressionEvaluator = expressionEvaluator;
+
+		Lazy<Optional<SqlIdentifier>> defaultSchema = Lazy.of(() -> {
+			if (StringUtils.hasText(namingStrategy.getSchema())) {
+				return Optional.of(createDerivedSqlIdentifier(namingStrategy.getSchema()));
+			}
+			return Optional.empty();
+		});
+
+		if (isAnnotationPresent(Table.class)) {
+
+			Table table = getRequiredAnnotation(Table.class);
+
+			// TODO: support expressions for schema
+			this.tableName = StringUtils.hasText(table.value()) ? Lazy.of(() -> createSqlIdentifier(table.value()))
+					: Lazy.of(() -> createDerivedSqlIdentifier(namingStrategy.getTableName(getType())));
+			this.tableNameExpression = detectExpression(table.value());
+
+			this.schemaName = StringUtils.hasText(table.schema())
+					? Lazy.of(() -> Optional.of(createSqlIdentifier(table.schema())))
+					: defaultSchema;
+
+		} else {
+
+			this.tableName = Lazy.of(() -> createDerivedSqlIdentifier(namingStrategy.getTableName(getType())));
+			this.tableNameExpression = null;
+			this.schemaName = defaultSchema;
+		}
+	}
+
+	/**
+	 * Returns a SpEL {@link Expression} if the given {@link String} is actually an expression that does not evaluate to a
+	 * {@link LiteralExpression} (indicating that no subsequent evaluation is necessary).
+	 *
+	 * @param potentialExpression can be {@literal null}
+	 * @return can be {@literal null}.
+	 */
+	@Nullable
+	private static Expression detectExpression(@Nullable String potentialExpression) {
+
+		if (!StringUtils.hasText(potentialExpression)) {
+			return null;
+		}
+
+		Expression expression = PARSER.parseExpression(potentialExpression, ParserContext.TEMPLATE_EXPRESSION);
+		return expression instanceof LiteralExpression ? null : expression;
+	}
+
+	private SqlIdentifier createSqlIdentifier(String name) {
+		return isForceQuote() ? SqlIdentifier.quoted(name) : SqlIdentifier.unquoted(name);
+	}
+
+	private SqlIdentifier createDerivedSqlIdentifier(String name) {
+		return new DerivedSqlIdentifier(name, isForceQuote());
+	}
+
+	public boolean isForceQuote() {
+		return forceQuote;
+	}
+
+	public void setForceQuote(boolean forceQuote) {
+		this.forceQuote = forceQuote;
+	}
+
+	@Override
+	public SqlIdentifier getTableName() {
+
+		if (tableNameExpression == null) {
+			return tableName.get();
+		}
+
+		return createSqlIdentifier(expressionEvaluator.evaluate(tableNameExpression));
+	}
+
+	@Override
+	public SqlIdentifier getQualifiedTableName() {
+
+		SqlIdentifier schema = schemaName.get().orElse(null);
+
+		if (schema == null) {
+			return getTableName();
+		}
+
+		return SqlIdentifier.from(schema, getTableName());
+	}
+
+	@Override
+	public SqlIdentifier getIdColumn() {
+		return getRequiredIdProperty().getColumnName();
+	}
+
+	@Override
+	public String toString() {
+		return String.format("BasicRelationalPersistentEntity<%s>", getType());
+	}
+}

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/BasicRelationalPersistentProperty.java

@@ -25,29 +25,40 @@
 import org.springframework.data.mapping.model.SimpleTypeHolder;
 import org.springframework.data.relational.core.mapping.Embedded.OnEmpty;
 import org.springframework.data.relational.core.sql.SqlIdentifier;
+import org.springframework.data.spel.EvaluationContextProvider;
 import org.springframework.data.util.Lazy;
 import org.springframework.data.util.Optionals;
+import org.springframework.expression.Expression;
+import org.springframework.expression.ParserContext;
+import org.springframework.expression.common.LiteralExpression;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
 /**
- * Meta data about a property to be used by repository implementations.
+ * SQL-specific {@link org.springframework.data.mapping.PersistentProperty} implementation.
  *
  * @author Jens Schauder
  * @author Greg Turnquist
  * @author Florian Lüdiger
  * @author Bastian Wilhelm
+ * @author Kurt Niemi
  */
 public class BasicRelationalPersistentProperty extends AnnotationBasedPersistentProperty<RelationalPersistentProperty>
 		implements RelationalPersistentProperty {
 
+	private static final SpelExpressionParser PARSER = new SpelExpressionParser();
+
 	private final Lazy<SqlIdentifier> columnName;
+	private final @Nullable Expression columnNameExpression;
 	private final Lazy<Optional<SqlIdentifier>> collectionIdColumnName;
 	private final Lazy<SqlIdentifier> collectionKeyColumnName;
 	private final Lazy<Boolean> isEmbedded;
 	private final Lazy<String> embeddedPrefix;
 	private final NamingStrategy namingStrategy;
 	private boolean forceQuote = true;
+	private ExpressionEvaluator spelExpressionProcessor = new ExpressionEvaluator(EvaluationContextProvider.DEFAULT);
 
 	/**
 	 * Creates a new {@link BasicRelationalPersistentProperty}.
@@ -88,12 +99,20 @@ public BasicRelationalPersistentProperty(Property property, PersistentEntity<?,
 				.map(Embedded::prefix) //
 				.orElse(""));
 
-		this.columnName = Lazy.of(() -> Optional.ofNullable(findAnnotation(Column.class)) //
-				.map(Column::value) //
-				.filter(StringUtils::hasText) //
-				.map(this::createSqlIdentifier) //
-				.orElseGet(() -> createDerivedSqlIdentifier(namingStrategy.getColumnName(this))));
+		if (isAnnotationPresent(Column.class)) {
 
+			Column column = getRequiredAnnotation(Column.class);
+
+			columnName = StringUtils.hasText(column.value()) ? Lazy.of(() -> createSqlIdentifier(column.value()))
+					: Lazy.of(() -> createDerivedSqlIdentifier(namingStrategy.getColumnName(this)));
+			columnNameExpression = detectExpression(column.value());
+
+		} else {
+			columnName = Lazy.of(() -> createDerivedSqlIdentifier(namingStrategy.getColumnName(this)));
+			columnNameExpression = null;
+		}
+
+		// TODO: support expressions for MappedCollection
 		this.collectionIdColumnName = Lazy.of(() -> Optionals
 				.toStream(Optional.ofNullable(findAnnotation(MappedCollection.class)) //
 						.map(MappedCollection::idColumn), //
@@ -110,6 +129,29 @@ public BasicRelationalPersistentProperty(Property property, PersistentEntity<?,
 				.orElseGet(() -> createDerivedSqlIdentifier(namingStrategy.getKeyColumn(this))));
 	}
 
+	void setSpelExpressionProcessor(ExpressionEvaluator spelExpressionProcessor) {
+		this.spelExpressionProcessor = spelExpressionProcessor;
+	}
+
+	/**
+	 * Returns a SpEL {@link Expression} if the given {@link String} is actually an expression that does not evaluate to a
+	 * {@link LiteralExpression} (indicating that no subsequent evaluation is necessary).
+	 *
+	 * @param potentialExpression can be {@literal null}
+	 * @return can be {@literal null}.
+	 */
+	@Nullable
+	private static Expression detectExpression(@Nullable String potentialExpression) {
+
+		if (!StringUtils.hasText(potentialExpression)) {
+			return null;
+		}
+
+		Expression expression = PARSER.parseExpression(potentialExpression, ParserContext.TEMPLATE_EXPRESSION);
+		return expression instanceof LiteralExpression ? null : expression;
+	}
+
+
 	private SqlIdentifier createSqlIdentifier(String name) {
 		return isForceQuote() ? SqlIdentifier.quoted(name) : SqlIdentifier.unquoted(name);
 	}
@@ -138,7 +180,12 @@ public boolean isEntity() {
 
 	@Override
 	public SqlIdentifier getColumnName() {
-		return columnName.get();
+
+		if (columnNameExpression == null) {
+			return columnName.get();
+		}
+
+		return createSqlIdentifier(spelExpressionProcessor.evaluate(columnNameExpression));
 	}
 
 	@Override

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/Column.java

@@ -34,7 +34,8 @@
 public @interface Column {
 
 	/**
-	 * The mapping column name.
+	 * The column name. The attribute supports SpEL expressions to dynamically calculate the column name on a
+	 * per-operation basis.
 	 */
 	String value() default "";
 

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/ExpressionEvaluator.java

@@ -0,0 +1,48 @@
+package org.springframework.data.relational.core.mapping;
+
+import org.springframework.data.spel.EvaluationContextProvider;
+import org.springframework.expression.EvaluationException;
+import org.springframework.expression.Expression;
+import org.springframework.util.Assert;
+
+/**
+ * Provide support for processing SpEL expressions in @Table and @Column annotations, or anywhere we want to use SpEL
+ * expressions and sanitize the result of the evaluated SpEL expression. The default sanitization allows for digits,
+ * alphabetic characters and _ characters and strips out any other characters. Custom sanitization (if desired) can be
+ * achieved by creating a class that implements the {@link SqlIdentifierSanitizer} interface and then invoking the
+ * {@link #setSpelExpressionResultSanitizer(SqlIdentifierSanitizer)} method.
+ *
+ * @author Kurt Niemi
+ * @see SqlIdentifierSanitizer
+ * @since 3.1
+ */
+class ExpressionEvaluator {
+
+	private EvaluationContextProvider provider;
+
+	private SqlIdentifierSanitizer sanitizer = SqlIdentifierSanitizer.words();
+
+	public ExpressionEvaluator(EvaluationContextProvider provider) {
+		this.provider = provider;
+	}
+
+	public String evaluate(Expression expression) throws EvaluationException {
+
+		Assert.notNull(expression, "Expression must not be null.");
+
+		String result = expression.getValue(provider.getEvaluationContext(null), String.class);
+
+		return sanitizer.sanitize(result);
+	}
+
+	public void setSanitizer(SqlIdentifierSanitizer sanitizer) {
+
+		Assert.notNull(sanitizer, "SqlIdentifierSanitizer must not be null");
+
+		this.sanitizer = sanitizer;
+	}
+
+	public void setProvider(EvaluationContextProvider provider) {
+		this.provider = provider;
+	}
+}