add: limit support

Signed-off-by: Artemiy Degtyarev <[email protected]>

Author: Artemiy Degtyarev

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/repository/query/PartTreeJdbcQuery.java

@@ -191,7 +191,7 @@ private JdbcQueryExecution<?> getQueryExecution(ResultProcessor processor,
 
 		if (getQueryMethod().isScrollQuery()) {
 			//noinspection unchecked
-			return new ScrollQueryExecution<>((JdbcQueryExecution<Collection<Object>>) queryExecution, accessor.getScrollPosition(), this.tree.getMaxResults(), tree.getSort());
+			return new ScrollQueryExecution<>((JdbcQueryExecution<Collection<Object>>) queryExecution, accessor.getScrollPosition(), this.tree.getMaxResults(), tree.getSort(), tree.getResultLimit());
 		}
 
 		if (getQueryMethod().isSliceQuery()) {
@@ -260,15 +260,17 @@ private JdbcQueryExecution<?> getJdbcQueryExecution(@Nullable ResultSetExtractor
 
 	static class ScrollQueryExecution<T> implements JdbcQueryExecution<Window<T>> {
 		private final JdbcQueryExecution<? extends Collection<T>> delegate;
-		private final ScrollPosition position;
+		private final @Nullable ScrollPosition position;
 		private final @Nullable Integer maxResults;
 		private final Sort sort;
+		private final Limit limit;
 
-		ScrollQueryExecution(JdbcQueryExecution<? extends Collection<T>> delegate, ScrollPosition position, @Nullable Integer maxResults, Sort sort) {
+		ScrollQueryExecution(JdbcQueryExecution<? extends Collection<T>> delegate, @Nullable ScrollPosition position, @Nullable Integer maxResults, Sort sort, Limit limit) {
 			this.delegate = delegate;
 			this.position = position;
 			this.maxResults = maxResults;
 			this.sort = sort;
+			this.limit = limit;
 		}
 
 		@Override
@@ -293,7 +295,16 @@ static class ScrollQueryExecution<T> implements JdbcQueryExecution<Window<T>> {
 				positionFunction = (ignoredI) -> ScrollPosition.of(finalKeys, ((KeysetScrollPosition) position).getDirection()) ;
 			}
 
-			boolean hasNext = resultList.size() >= maxResults;
+			if (positionFunction == null)
+				throw new UnsupportedOperationException("Not supported scroll type.");
+
+			boolean hasNext;
+			if (maxResults != null)
+				hasNext = resultList.size() >= maxResults;
+			else if (limit.isLimited())
+				hasNext = resultList.size() >= limit.max();
+			else
+				hasNext = !resultList.isEmpty();
 
 			return Window.from(resultList, positionFunction, hasNext);
 		}