Update documentation

Document on how to use the BeanWrapperRowMapper with the StreamingXlsxItemReader as that requires a bit more configuration due to the streaming nature.

Next to the documentation also added a test case for this to show how to configure it as well.

Closes: #115

spring-batch-excel/src/test/java/org/springframework/batch/extensions/excel/streaming/StreamingXlsxMappingTests.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2002-2024 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.batch.extensions.excel.streaming;
+
+import java.util.Locale;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.batch.extensions.excel.Player;
+import org.springframework.batch.extensions.excel.ReflectionTestUtils;
+import org.springframework.batch.extensions.excel.mapping.BeanWrapperRowMapper;
+import org.springframework.batch.extensions.excel.support.rowset.DefaultRowSetFactory;
+import org.springframework.batch.extensions.excel.support.rowset.StaticColumnNameExtractor;
+import org.springframework.batch.item.ExecutionContext;
+import org.springframework.core.io.ClassPathResource;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class StreamingXlsxMappingTests {
+
+	@Test
+	void readAndMapRowsUsingRowMapper() throws Exception {
+		var columns = new String[] {"id", "position", "lastName", "firstName", "birthYear", "debutYear", "comment"};
+		var rowSetFactory = new DefaultRowSetFactory();
+		rowSetFactory.setColumnNameExtractor(new StaticColumnNameExtractor(columns));
+
+		var mapper = new BeanWrapperRowMapper<Player>();
+		mapper.setTargetType(Player.class);
+
+		var reader = new StreamingXlsxItemReader<Player>();
+		reader.setResource(new ClassPathResource("player.xlsx"));
+		reader.setRowSetFactory(rowSetFactory);
+		reader.setRowMapper(mapper);
+		reader.setLinesToSkip(1); // Skip header
+		reader.setUserLocale(Locale.US); // Use a Locale to not be dependent on environment
+		reader.afterPropertiesSet();
+
+		reader.open(new ExecutionContext());
+		Player row;
+		do {
+			row = reader.read();
+		}
+		while (row != null);
+
+		Integer readCount = (Integer) ReflectionTestUtils.getField(reader, "currentItemCount");
+		assertThat(readCount).isEqualTo(4321);
+	}
+}