Prefer Slice over Page in RepositoryItemReader

Resolves #4115

Author: hpoettker

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/data/RepositoryItemReader.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2023 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.
@@ -28,9 +28,9 @@
 import org.springframework.batch.item.adapter.DynamicMethodInvocationException;
 import org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader;
 import org.springframework.beans.factory.InitializingBean;
-import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Slice;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.repository.PagingAndSortingRepository;
 import org.springframework.lang.Nullable;
@@ -168,7 +168,7 @@ protected T doRead() throws Exception {
 				results = doPageRead();
 				page ++;
 
-				if(results.size() <= 0) {
+				if(results.isEmpty()) {
 					return null;
 				}
 
@@ -220,7 +220,7 @@ protected List<T> doPageRead() throws Exception {
 
 		invoker.setArguments(parameters.toArray());
 
-		Page<T> curPage = (Page<T>) doInvoke(invoker);
+		Slice<T> curPage = (Slice<T>) doInvoke(invoker);
 
 		return curPage.getContent();
 	}

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/data/RepositoryItemReaderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2020 the original author or authors.
+ * Copyright 2013-2023 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.
@@ -29,10 +29,11 @@
 
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.adapter.DynamicMethodInvocationException;
-import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageImpl;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Slice;
+import org.springframework.data.domain.SliceImpl;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.domain.Sort.Direction;
 import org.springframework.data.repository.PagingAndSortingRepository;
@@ -263,7 +264,7 @@ public void testDifferentTypes() throws Exception {
 		reader.setMethodName("findFirstNames");
 
 		ArgumentCaptor<PageRequest> pageRequestContainer = ArgumentCaptor.forClass(PageRequest.class);
-		when(differentRepository.findFirstNames(pageRequestContainer.capture())).thenReturn(new PageImpl<>(singletonList(
+		when(differentRepository.findFirstNames(pageRequestContainer.capture())).thenReturn(new SliceImpl<>(singletonList(
 			"result"
 		)));
 
@@ -365,7 +366,7 @@ public void testResetOfPage() throws Exception {
 	}
 
 	public interface TestRepository extends PagingAndSortingRepository<Map, Long> {
-		Page<String> findFirstNames(Pageable pageable);
+		Slice<String> findFirstNames(Pageable pageable);
 	}
 
 	// Simple object for readability

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/data/builder/RepositoryItemReaderBuilderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2018 the original author or authors.
+ * Copyright 2017-2023 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.
@@ -28,8 +28,8 @@
 import org.mockito.MockitoAnnotations;
 
 import org.springframework.batch.item.data.RepositoryItemReader;
-import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Slice;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.repository.PagingAndSortingRepository;
 
@@ -54,7 +54,7 @@ public class RepositoryItemReaderBuilderTests {
 	private TestRepository repository;
 
 	@Mock
-	private Page<String> page;
+	private Slice<String> slice;
 
 	private Map<String, Sort.Direction> sorts;
 
@@ -69,9 +69,9 @@ public void setUp() throws Exception {
 
 		List<String> testResult = new ArrayList<>();
 		testResult.add(TEST_CONTENT);
-		when(page.getContent()).thenReturn(testResult);
-		when(page.getSize()).thenReturn(5);
-		when(this.repository.foo(this.pageRequestContainer.capture())).thenReturn(this.page);
+		when(slice.getContent()).thenReturn(testResult);
+		when(slice.getSize()).thenReturn(5);
+		when(this.repository.foo(this.pageRequestContainer.capture())).thenReturn(this.slice);
 	}
 
 	@Test
@@ -116,7 +116,7 @@ public void testRepositoryMethodReferenceWithArgs() throws Exception {
 		ArgumentCaptor<String> arg2Captor = ArgumentCaptor.forClass(String.class);
 		ArgumentCaptor<String> arg3Captor = ArgumentCaptor.forClass(String.class);
 		when(this.repository.foo(arg1Captor.capture(), arg2Captor.capture(), arg3Captor.capture(),
-				this.pageRequestContainer.capture())).thenReturn(this.page);
+				this.pageRequestContainer.capture())).thenReturn(this.slice);
 
 		String result = (String) reader.read();
 		assertEquals("Result returned from reader was not expected value.", TEST_CONTENT, result);
@@ -244,7 +244,7 @@ public void testArguments() throws Exception {
 		ArgumentCaptor<String> arg2Captor = ArgumentCaptor.forClass(String.class);
 		ArgumentCaptor<String> arg3Captor = ArgumentCaptor.forClass(String.class);
 		when(this.repository.foo(arg1Captor.capture(), arg2Captor.capture(), arg3Captor.capture(),
-				this.pageRequestContainer.capture())).thenReturn(this.page);
+				this.pageRequestContainer.capture())).thenReturn(this.slice);
 
 		RepositoryItemReader<Object> reader = new RepositoryItemReaderBuilder<>().repository(this.repository)
 				.sorts(this.sorts)
@@ -264,7 +264,7 @@ public void testVarargArguments() throws Exception {
 		ArgumentCaptor<String> arg2Captor = ArgumentCaptor.forClass(String.class);
 		ArgumentCaptor<String> arg3Captor = ArgumentCaptor.forClass(String.class);
 		when(this.repository.foo(arg1Captor.capture(), arg2Captor.capture(), arg3Captor.capture(),
-				this.pageRequestContainer.capture())).thenReturn(this.page);
+				this.pageRequestContainer.capture())).thenReturn(this.slice);
 
 		RepositoryItemReader<Object> reader = new RepositoryItemReaderBuilder<>().repository(this.repository)
 				.sorts(this.sorts)

spring-batch-samples/src/main/java/org/springframework/batch/sample/data/CustomerCreditRepository.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013 the original author or authors.
+ * Copyright 2013-2023 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.
@@ -18,10 +18,10 @@
 import java.math.BigDecimal;
 
 import org.springframework.batch.sample.domain.trade.CustomerCredit;
-import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Slice;
 import org.springframework.data.repository.PagingAndSortingRepository;
 
 public interface CustomerCreditRepository extends PagingAndSortingRepository<CustomerCredit, Long>{
-	Page<CustomerCredit> findByCreditGreaterThan(BigDecimal credit, Pageable request);
+	Slice<CustomerCredit> findByCreditGreaterThan(BigDecimal credit, Pageable request);
 }