Consistently return empty array in case of empty batch arguments

Issue: SPR-17476

(cherry picked from commit 362c59c)

Author: jhoeller

spring-jdbc/src/main/java/org/springframework/jdbc/core/BatchUpdateUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -25,24 +25,29 @@
  * Mainly for internal use within the framework.
  *
  * @author Thomas Risberg
+ * @author Juergen Hoeller
  * @since 3.0
  */
 public abstract class BatchUpdateUtils {
 
 	public static int[] executeBatchUpdate(
-			String sql, final List<Object[]> batchValues, final int[] columnTypes, JdbcOperations jdbcOperations) {
+			String sql, final List<Object[]> batchArgs, final int[] columnTypes, JdbcOperations jdbcOperations) {
+
+		if (batchArgs.isEmpty()) {
+			return new int[0];
+		}
 
 		return jdbcOperations.batchUpdate(
 				sql,
 				new BatchPreparedStatementSetter() {
 					@Override
 					public void setValues(PreparedStatement ps, int i) throws SQLException {
-						Object[] values = batchValues.get(i);
+						Object[] values = batchArgs.get(i);
 						setStatementParameters(values, ps, columnTypes);
 					}
 					@Override
 					public int getBatchSize() {
-						return batchValues.size();
+						return batchArgs.size();
 					}
 				});
 	}

spring-jdbc/src/main/java/org/springframework/jdbc/core/namedparam/NamedParameterBatchUpdateUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -28,15 +28,16 @@
  * Mainly for internal use within the framework.
  *
  * @author Thomas Risberg
+ * @author Juergen Hoeller
  * @since 3.0
  */
 public class NamedParameterBatchUpdateUtils extends BatchUpdateUtils {
 
-	public static int[] executeBatchUpdateWithNamedParameters(final ParsedSql parsedSql,
-			final SqlParameterSource[] batchArgs, JdbcOperations jdbcOperations) {
+	public static int[] executeBatchUpdateWithNamedParameters(
+			final ParsedSql parsedSql, final SqlParameterSource[] batchArgs, JdbcOperations jdbcOperations) {
 
-		if (batchArgs.length <= 0) {
-			return new int[] {0};
+		if (batchArgs.length == 0) {
+			return new int[0];
 		}
 
 		String sqlToUse = NamedParameterUtils.substituteNamedParameters(parsedSql, batchArgs[0]);