Fix incorrect behaviour of RepositoryItemReader#jumpToItem() on restart

build.gradle

@@ -455,6 +455,7 @@ project('spring-batch-infrastructure-tests') {
 		testCompile("org.springframework:spring-oxm:$springVersion") {
 			exclude group: 'commons-lang', module: 'commons-lang'
 		}
+		testCompile "org.springframework.data:spring-data-jpa:$springDataJpaVersion"
 		testCompile "org.springframework:spring-jdbc:$springVersion"
 		testCompile "org.springframework:spring-test:$springVersion"
 		testCompile "org.mockito:mockito-core:$mockitoVersion"

spring-batch-infrastructure-tests/src/test/java/org/springframework/batch/item/database/RepositoryItemReaderIntegrationTests.java

@@ -0,0 +1,116 @@
+/*
+ * Copyright 2016 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
+ *
+ *      http://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.item.database;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.List;
+
+import org.junit.After;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.batch.item.ExecutionContext;
+import org.springframework.batch.item.data.RepositoryItemReader;
+import org.springframework.batch.item.sample.books.Author;
+import org.springframework.batch.item.sample.books.Book;
+import org.springframework.batch.item.sample.books.data.SimpleService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(locations = "RepositoryItemReaderCommonTests-context.xml")
+public class RepositoryItemReaderIntegrationTests {
+
+    private static final String CONTEXT_KEY = "RepositoryItemReader.read.count";
+
+    @Autowired
+    private SimpleService service;
+
+    @Autowired
+    private RepositoryItemReader<Author> reader;
+
+    @After
+    public void reinitializeReader() {
+        reader.close();
+    }
+
+    @Test
+    public void testReadFromFirstPos() throws Exception {
+        service.openReader(new ExecutionContext());
+
+        final List<Book> books = service.nextAuthorBooks();
+
+        assertEquals("Books list size", 2, books.size());
+        assertEquals("First book", "author 1 - book 1", books.get(0).getName());
+        assertEquals("Second book", "author 1 - book 2", books.get(1).getName());
+    }
+
+    @Test
+    public void testReadFromWithinPage() throws Exception {
+        reader.setCurrentItemCount(1);
+        service.openReader(new ExecutionContext());
+
+        final List<Book> books = service.nextAuthorBooks();
+
+        assertEquals("Books list size", 2, books.size());
+        assertEquals("First book", "author 2 - book 1", books.get(0).getName());
+        assertEquals("Second book", "author 2 - book 2", books.get(1).getName());
+    }
+
+    @Test
+    public void testReadFromNewPage() throws Exception {
+        reader.setPageSize(2);
+        reader.setCurrentItemCount(2); // 3rd item = 1rst of page 2
+        service.openReader(new ExecutionContext());
+
+        final List<Book> books = service.nextAuthorBooks();
+
+        assertEquals("Books list size", 2, books.size());
+        assertEquals("First book", "author 3 - book 1", books.get(0).getName());
+        assertEquals("Second book", "author 3 - book 2", books.get(1).getName());
+    }
+
+    @Test
+    public void testReadFromWithinPage_Restart() throws Exception {
+        final ExecutionContext executionContext = new ExecutionContext();
+        executionContext.putInt(CONTEXT_KEY, 1);
+        service.openReader(executionContext);
+
+        final List<Book> books = service.nextAuthorBooks();
+
+        assertEquals("Books list size", 2, books.size());
+        assertEquals("First book", "author 2 - book 1", books.get(0).getName());
+        assertEquals("Second book", "author 2 - book 2", books.get(1).getName());
+    }
+
+    @Test
+    public void testReadFromNewPage_Restart() throws Exception {
+        reader.setPageSize(2);
+        final ExecutionContext executionContext = new ExecutionContext();
+        executionContext.putInt(CONTEXT_KEY, 2);
+        service.openReader(executionContext);
+
+        final List<Book> books = service.nextAuthorBooks();
+
+        assertEquals("Books list size", 2, books.size());
+        assertEquals("First book", "author 3 - book 1", books.get(0).getName());
+        assertEquals("Second book", "author 3 - book 2", books.get(1).getName());
+    }
+
+}

spring-batch-infrastructure-tests/src/test/java/org/springframework/batch/item/sample/books/Author.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2016 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
+ *
+ *      http://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.item.sample.books;
+
+import javax.persistence.Basic;
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.OneToMany;
+import javax.persistence.Table;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * Basic domain object with a lazy one-to-many association.
+ *
+ * @author Antoine Kapps
+ */
+@Entity
+@Table(name = "T_AUTHORS")
+public class Author {
+
+    @Id
+    private int id;
+
+    @Basic
+    private String name;
+
+    @OneToMany
+    @JoinColumn(name = "AUTHOR_ID")
+    private List<Book> books;
+
+    public int getId() {
+        return id;
+    }
+    public String getName() {
+        return name;
+    }
+    public List<Book> getBooks() {
+        return books;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Author author = (Author) o;
+        return id == author.id &&
+                Objects.equals(name, author.name) &&
+                Objects.equals(books, author.books);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id, name, books);
+    }
+}

spring-batch-infrastructure-tests/src/test/java/org/springframework/batch/item/sample/books/Book.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2016 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
+ *
+ *      http://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.item.sample.books;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.Table;
+import java.util.Objects;
+
+/**
+ * Simple domain object implied in an association with {@link Author}.
+ *
+ * @author Antoine Kapps
+ */
+@Entity
+@Table(name = "T_BOOKS")
+public class Book {
+
+    @Id
+    private int id;
+    private String name;
+
+    public int getId() {
+        return id;
+    }
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Book book = (Book) o;
+        return id == book.id &&
+                Objects.equals(name, book.name);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id, name);
+    }
+}

spring-batch-infrastructure-tests/src/test/java/org/springframework/batch/item/sample/books/data/AuthorRepository.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2016 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
+ *
+ *      http://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.item.sample.books.data;
+
+import org.springframework.batch.item.sample.books.Author;
+import org.springframework.data.repository.PagingAndSortingRepository;
+import org.springframework.stereotype.Repository;
+
+
+@Repository
+public interface AuthorRepository extends PagingAndSortingRepository<Author, Integer> {
+}

spring-batch-infrastructure-tests/src/test/java/org/springframework/batch/item/sample/books/data/SimpleService.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2016 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
+ *
+ *      http://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.item.sample.books.data;
+
+import javax.transaction.Transactional;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.springframework.batch.item.ExecutionContext;
+import org.springframework.batch.item.data.RepositoryItemReader;
+import org.springframework.batch.item.sample.books.Author;
+import org.springframework.batch.item.sample.books.Book;
+
+/**
+ * A simple service based upon a {@link RepositoryItemReader}
+ */
+public class SimpleService {
+
+    private final RepositoryItemReader<Author> itemReader;
+
+    public SimpleService(RepositoryItemReader<Author> itemReader) {
+        this.itemReader = itemReader;
+    }
+
+    // Prepare the reader
+    public void openReader(ExecutionContext executionContext) throws Exception {
+        itemReader.open(executionContext);
+    }
+
+    // Reads next Author and returns his (lazy-loaded) books, inside a transaction (simulates the chunk's transaction)
+    @Transactional
+    public List<Book> nextAuthorBooks() throws Exception {
+        List<Book> result = new ArrayList<>();
+
+        final Author nextAuthor = itemReader.read();
+        if (nextAuthor != null) {
+            result.addAll(nextAuthor.getBooks());
+        }
+
+        return result;
+    }
+}

spring-batch-infrastructure-tests/src/test/resources/org/springframework/batch/item/database/RepositoryItemReaderCommonTests-context.xml

@@ -0,0 +1,56 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	   xmlns:jpa="http://www.springframework.org/schema/data/jpa"
+	   xmlns:tx="http://www.springframework.org/schema/tx"
+	   xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
+	   http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa.xsd
+	   http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
+
+	<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
+		<property name="driverClassName" value="org.hsqldb.jdbcDriver" />
+		<property name="url" value="jdbc:hsqldb:mem:testjpamydb" />
+	</bean>
+
+	<!--  Initialise the database -->
+	<bean id="dataSourceInitializer" class="test.jdbc.datasource.DataSourceInitializer">
+		<property name="dataSource" ref="dataSource"/>
+		<property name="initialize" value="true"/>
+		<property name="initScripts">
+			<list>
+				<value>classpath:org/springframework/batch/item/database/init-books-schema.sql</value>
+			</list>
+		</property>
+	</bean>
+
+	<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
+		<property name="entityManagerFactory" ref="entityManagerFactory" />
+	</bean>
+	<tx:annotation-driven transaction-manager="transactionManager"/>
+
+	<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
+		<property name="dataSource" ref="dataSource"/>
+		<property name="jpaVendorAdapter">
+			<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
+				<property name="showSql" value="false"/>
+			</bean>
+		</property>
+		<property name="packagesToScan" value="org.springframework.batch.item.sample.books"/>
+	</bean>
+
+	<jpa:repositories base-package="org.springframework.batch.item.sample.books.data"/>
+
+	<bean id="authorRepositoryItemReader" class="org.springframework.batch.item.data.RepositoryItemReader">
+		<property name="repository" ref="authorRepository"/>
+		<property name="methodName" value="findAll"/>
+		<property name="sort">
+			<map>
+				<entry key="id" value="ASC"/>
+			</map>
+		</property>
+	</bean>
+
+	<bean id="myService" class="org.springframework.batch.item.sample.books.data.SimpleService">
+		<constructor-arg ref="authorRepositoryItemReader"/>
+	</bean>
+
+</beans>