removed function indirection for condition construction

Author: schauder

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/convert/SqlGenerator.java

@@ -33,7 +33,6 @@
 import org.springframework.data.relational.core.query.CriteriaDefinition;
 import org.springframework.data.relational.core.query.Query;
 import org.springframework.data.relational.core.sql.*;
-import org.springframework.data.relational.core.sql.render.RenderContext;
 import org.springframework.data.relational.core.sql.render.SqlRenderer;
 import org.springframework.data.util.Lazy;
 import org.springframework.data.util.Pair;
@@ -94,10 +93,6 @@ class SqlGenerator {
 	private final QueryMapper queryMapper;
 	private final Dialect dialect;
 
-	private final Function<Map<AggregatePath, Column>, Condition> inCondition;
-	private final Function<Map<AggregatePath, Column>, Condition> equalityCondition;
-	private final Function<Map<AggregatePath, Column>, Condition> notNullCondition;
-
 	/**
 	 * Create a new {@link SqlGenerator} given {@link RelationalMappingContext} and {@link RelationalPersistentEntity}.
 	 *
@@ -116,11 +111,6 @@ class SqlGenerator {
 		this.columns = new Columns(entity, mappingContext, converter);
 		this.queryMapper = new QueryMapper(converter);
 		this.dialect = dialect;
-
-		inCondition = inCondition();
-		equalityCondition = equalityCondition();
-		notNullCondition = isNotNullCondition();
-
 	}
 
 	/**
@@ -208,7 +198,7 @@ private Condition getSubselectCondition(AggregatePath path,
 	}
 
 	private Expression toExpression(Map<AggregatePath, Column> columnsMap) {
-			return TupleExpression.maybeWrap(new ArrayList<>(columnsMap.values()));
+		return TupleExpression.maybeWrap(new ArrayList<>(columnsMap.values()));
 	}
 
 	private BindMarker getBindMarker(SqlIdentifier columnName) {
@@ -454,7 +444,7 @@ String createDeleteAllSql(@Nullable PersistentPropertyPath<RelationalPersistentP
 			return render(deleteAll.build());
 		}
 
-		return createDeleteByPathAndCriteria(mappingContext.getAggregatePath(path), notNullCondition);
+		return createDeleteByPathAndCriteria(mappingContext.getAggregatePath(path), this::isNotNullCondition);
 	}
 
 	/**
@@ -465,7 +455,7 @@ String createDeleteAllSql(@Nullable PersistentPropertyPath<RelationalPersistentP
 	 * @return the statement as a {@link String}. Guaranteed to be not {@literal null}.
 	 */
 	String createDeleteByPath(PersistentPropertyPath<RelationalPersistentProperty> path) {
-		return createDeleteByPathAndCriteria(mappingContext.getAggregatePath(path), equalityCondition);
+		return createDeleteByPathAndCriteria(mappingContext.getAggregatePath(path), this::equalityCondition);
 	}
 
 	/**
@@ -476,63 +466,55 @@ String createDeleteByPath(PersistentPropertyPath<RelationalPersistentProperty> p
 	 * @return the statement as a {@link String}. Guaranteed to be not {@literal null}.
 	 */
 	String createDeleteInByPath(PersistentPropertyPath<RelationalPersistentProperty> path) {
-		return createDeleteByPathAndCriteria(mappingContext.getAggregatePath(path), inCondition);
+		return createDeleteByPathAndCriteria(mappingContext.getAggregatePath(path), this::inCondition);
 	}
 
 	/**
-	 * Constructs a function for constructing a where condition. The where condition will be of the form
-	 * {@literal <columns> IN :bind-marker}
+	 * Constructs a where condition. The where condition will be of the form {@literal <columns> IN :bind-marker}
 	 */
-	private Function<Map<AggregatePath, Column>, Condition> inCondition() {
-
-		return columnMap -> {
+	private Condition inCondition(Map<AggregatePath, Column> columnMap) {
 
-			List<Column> columns = List.copyOf(columnMap.values());
+		List<Column> columns = List.copyOf(columnMap.values());
 
-			if (columns.size() == 1) {
-				return Conditions.in(columns.get(0), getBindMarker(IDS_SQL_PARAMETER));
-			}
-			return Conditions.in(TupleExpression.create(columns), getBindMarker(IDS_SQL_PARAMETER));
-		};
+		if (columns.size() == 1) {
+			return Conditions.in(columns.get(0), getBindMarker(IDS_SQL_PARAMETER));
+		}
+		return Conditions.in(TupleExpression.create(columns), getBindMarker(IDS_SQL_PARAMETER));
 	}
 
 	/**
-	 * Constructs a function for constructing a where. The where condition will be of the form
+	 * Constructs a where-condition. The where condition will be of the form
 	 * {@literal <column-a> = :bind-marker-a AND <column-b> = :bind-marker-b ...}
 	 */
-	private Function<Map<AggregatePath, Column>, Condition> equalityCondition() {
+	private Condition equalityCondition(Map<AggregatePath, Column> columnMap) {
 
 		AggregatePath.ColumnInfos idColumnInfos = mappingContext.getAggregatePath(entity).getTableInfo().idColumnInfos();
 
-		return columnMap -> {
-
-			Condition result = null;
-			for (Map.Entry<AggregatePath, Column> entry : columnMap.entrySet()) {
-				BindMarker bindMarker = getBindMarker(idColumnInfos.get(entry.getKey()).name());
-				Comparison singleCondition = entry.getValue().isEqualTo(bindMarker);
+		Condition result = null;
+		for (Map.Entry<AggregatePath, Column> entry : columnMap.entrySet()) {
+			BindMarker bindMarker = getBindMarker(idColumnInfos.get(entry.getKey()).name());
+			Comparison singleCondition = entry.getValue().isEqualTo(bindMarker);
 
-				result = result == null ? singleCondition : result.and(singleCondition);
-			}
-			return result;
-		};
+			result = result == null ? singleCondition : result.and(singleCondition);
+		}
+		Assert.state(result != null, "We need at least one condition");
+		return result;
 	}
 
 	/**
 	 * Constructs a function for constructing where a condition. The where condition will be of the form
 	 * {@literal <column-a> IS NOT NULL AND <column-b> IS NOT NULL ... }
 	 */
-	private Function<Map<AggregatePath, Column>, Condition> isNotNullCondition() {
-
-		return columnMap -> {
+	private Condition isNotNullCondition(Map<AggregatePath, Column> columnMap) {
 
-			Condition result = null;
-			for (Column column : columnMap.values()) {
-				Condition singleCondition = column.isNotNull();
+		Condition result = null;
+		for (Column column : columnMap.values()) {
+			Condition singleCondition = column.isNotNull();
 
-				result = result == null ? singleCondition : result.and(singleCondition);
-			}
-			return result;
-		};
+			result = result == null ? singleCondition : result.and(singleCondition);
+		}
+		Assert.state(result != null, "We need at least one condition");
+		return result;
 	}
 
 	private String createFindOneSql() {