Configure the right FieldSetMapper based on the type of items in FlatFileItemReaderBuilder

Resolves #4160

Author: fmbenhassine

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/file/builder/FlatFileItemReaderBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2020 the original author or authors.
+ * Copyright 2016-2022 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.
@@ -37,6 +37,7 @@
 import org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper;
 import org.springframework.batch.item.file.mapping.DefaultLineMapper;
 import org.springframework.batch.item.file.mapping.FieldSetMapper;
+import org.springframework.batch.item.file.mapping.RecordFieldSetMapper;
 import org.springframework.batch.item.file.separator.RecordSeparatorPolicy;
 import org.springframework.batch.item.file.separator.SimpleRecordSeparatorPolicy;
 import org.springframework.batch.item.file.transform.DefaultFieldSetFactory;
@@ -459,21 +460,26 @@ else if (this.delimitedBuilder != null) {
 			}
 
 			if (this.targetType != null || StringUtils.hasText(this.prototypeBeanName)) {
-				BeanWrapperFieldSetMapper<T> mapper = new BeanWrapperFieldSetMapper<>();
-				mapper.setTargetType(this.targetType);
-				mapper.setPrototypeBeanName(this.prototypeBeanName);
-				mapper.setStrict(this.beanMapperStrict);
-				mapper.setBeanFactory(this.beanFactory);
-				mapper.setDistanceLimit(this.distanceLimit);
-				mapper.setCustomEditors(this.customEditors);
-				try {
-					mapper.afterPropertiesSet();
+				if (this.targetType != null && this.targetType.isRecord()) {
+					RecordFieldSetMapper<T> mapper = new RecordFieldSetMapper(this.targetType);
+					lineMapper.setFieldSetMapper(mapper);
 				}
-				catch (Exception e) {
-					throw new IllegalStateException("Unable to initialize BeanWrapperFieldSetMapper", e);
+				else {
+					BeanWrapperFieldSetMapper<T> mapper = new BeanWrapperFieldSetMapper<>();
+					mapper.setTargetType(this.targetType);
+					mapper.setPrototypeBeanName(this.prototypeBeanName);
+					mapper.setStrict(this.beanMapperStrict);
+					mapper.setBeanFactory(this.beanFactory);
+					mapper.setDistanceLimit(this.distanceLimit);
+					mapper.setCustomEditors(this.customEditors);
+					try {
+						mapper.afterPropertiesSet();
+						lineMapper.setFieldSetMapper(mapper);
+					}
+					catch (Exception e) {
+						throw new IllegalStateException("Unable to initialize BeanWrapperFieldSetMapper", e);
+					}
 				}
-
-				lineMapper.setFieldSetMapper(mapper);
 			}
 			else if (this.fieldSetMapper != null) {
 				lineMapper.setFieldSetMapper(this.fieldSetMapper);

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/file/builder/FlatFileItemReaderBuilderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2020 the original author or authors.
+ * Copyright 2016-2022 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.
@@ -20,11 +20,16 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import org.junit.Assert;
 import org.junit.Test;
 
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.file.FlatFileItemReader;
+import org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper;
+import org.springframework.batch.item.file.mapping.DefaultLineMapper;
+import org.springframework.batch.item.file.mapping.RecordFieldSetMapper;
 import org.springframework.batch.item.file.separator.DefaultRecordSeparatorPolicy;
+import org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor;
 import org.springframework.batch.item.file.transform.DefaultFieldSet;
 import org.springframework.batch.item.file.transform.DelimitedLineTokenizer;
 import org.springframework.batch.item.file.transform.FieldSet;
@@ -442,6 +447,49 @@ public void testErrorMessageWhenNoLineTokenizerWasProvided() {
 		}
 	}
 
+	@Test
+	public void testSetupWithRecordTargetType() {
+		// given
+		record Person(int id, String name) {
+		}
+
+		// when
+		FlatFileItemReader<Person> reader = new FlatFileItemReaderBuilder<Person>().name("personReader")
+				.resource(getResource("1,foo")).targetType(Person.class).delimited().names("id", "name").build();
+
+		// then
+		Object lineMapper = ReflectionTestUtils.getField(reader, "lineMapper");
+		Assert.assertNotNull(lineMapper);
+		Assert.assertTrue(lineMapper instanceof DefaultLineMapper);
+		Object fieldSetMapper = ReflectionTestUtils.getField(lineMapper, "fieldSetMapper");
+		Assert.assertNotNull(fieldSetMapper);
+		Assert.assertTrue(fieldSetMapper instanceof RecordFieldSetMapper);
+	}
+
+	@Test
+	public void testSetupWithClassTargetType() {
+		// given
+		class Person {
+
+			int id;
+
+			String name;
+
+		}
+
+		// when
+		FlatFileItemReader<Person> reader = new FlatFileItemReaderBuilder<Person>().name("personReader")
+				.resource(getResource("1,foo")).targetType(Person.class).delimited().names("id", "name").build();
+
+		// then
+		Object lineMapper = ReflectionTestUtils.getField(reader, "lineMapper");
+		Assert.assertNotNull(lineMapper);
+		Assert.assertTrue(lineMapper instanceof DefaultLineMapper);
+		Object fieldSetMapper = ReflectionTestUtils.getField(lineMapper, "fieldSetMapper");
+		Assert.assertNotNull(fieldSetMapper);
+		Assert.assertTrue(fieldSetMapper instanceof BeanWrapperFieldSetMapper);
+	}
+
 	private Resource getResource(String contents) {
 		return new ByteArrayResource(contents.getBytes());
 	}