Move KafkaItemReader integration tests to a separate class

Tests requiring a kafka broker should be part of the
integration tests suite, not the unit tests suite.
This commit is contained in:
Mahmoud Ben Hassine
2023-07-05 08:54:11 +02:00
parent d6904ba43b
commit 060c96f01f
2 changed files with 335 additions and 303 deletions

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@@ -0,0 +1,329 @@
/*
* Copyright 2019-2023 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.
* 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.item.kafka;
import java.time.Duration;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import org.apache.kafka.clients.admin.NewTopic;
import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.clients.consumer.OffsetAndMetadata;
import org.apache.kafka.common.TopicPartition;
import org.apache.kafka.common.serialization.StringDeserializer;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.springframework.batch.item.ExecutionContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.core.DefaultKafkaProducerFactory;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.kafka.core.ProducerFactory;
import org.springframework.kafka.test.EmbeddedKafkaBroker;
import org.springframework.kafka.test.context.EmbeddedKafka;
import org.springframework.kafka.test.utils.KafkaTestUtils;
import org.springframework.test.context.junit.jupiter.SpringExtension;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.containsInAnyOrder;
import static org.hamcrest.Matchers.is;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNull;
/**
* @author Mathieu Ouellet
* @author Mahmoud Ben Hassine
*/
@EmbeddedKafka
@ExtendWith(SpringExtension.class)
class KafkaItemReaderIntegrationTests {
@Autowired
private EmbeddedKafkaBroker embeddedKafka;
private KafkaItemReader<String, String> reader;
private KafkaTemplate<String, String> template;
private Properties consumerProperties;
@BeforeAll
static void setUpTopics(@Autowired EmbeddedKafkaBroker embeddedKafka) {
embeddedKafka.addTopics(new NewTopic("topic1", 1, (short) 1), new NewTopic("topic2", 2, (short) 1),
new NewTopic("topic3", 1, (short) 1), new NewTopic("topic4", 2, (short) 1),
new NewTopic("topic5", 1, (short) 1), new NewTopic("topic6", 1, (short) 1));
}
@BeforeEach
void setUp() {
Map<String, Object> producerProperties = KafkaTestUtils.producerProps(embeddedKafka);
ProducerFactory<String, String> producerFactory = new DefaultKafkaProducerFactory<>(producerProperties);
this.template = new KafkaTemplate<>(producerFactory);
this.consumerProperties = new Properties();
this.consumerProperties.setProperty(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG,
embeddedKafka.getBrokersAsString());
this.consumerProperties.setProperty(ConsumerConfig.GROUP_ID_CONFIG, "1");
this.consumerProperties.setProperty(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG,
StringDeserializer.class.getName());
this.consumerProperties.setProperty(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG,
StringDeserializer.class.getName());
}
@Test
void testReadFromSinglePartition() throws ExecutionException, InterruptedException {
this.template.setDefaultTopic("topic1");
var futures = new ArrayList<CompletableFuture<?>>();
futures.add(this.template.sendDefault("val0"));
futures.add(this.template.sendDefault("val1"));
futures.add(this.template.sendDefault("val2"));
futures.add(this.template.sendDefault("val3"));
for (var future : futures) {
future.get();
}
this.reader = new KafkaItemReader<>(this.consumerProperties, "topic1", 0);
this.reader.setPollTimeout(Duration.ofSeconds(1));
this.reader.open(new ExecutionContext());
String item = this.reader.read();
assertThat(item, is("val0"));
item = this.reader.read();
assertThat(item, is("val1"));
item = this.reader.read();
assertThat(item, is("val2"));
item = this.reader.read();
assertThat(item, is("val3"));
item = this.reader.read();
assertNull(item);
this.reader.close();
}
@Test
void testReadFromSinglePartitionFromCustomOffset() throws ExecutionException, InterruptedException {
this.template.setDefaultTopic("topic5");
var futures = new ArrayList<CompletableFuture<?>>();
futures.add(this.template.sendDefault("val0")); // <-- offset 0
futures.add(this.template.sendDefault("val1")); // <-- offset 1
futures.add(this.template.sendDefault("val2")); // <-- offset 2
futures.add(this.template.sendDefault("val3")); // <-- offset 3
for (var future : futures) {
future.get();
}
this.reader = new KafkaItemReader<>(this.consumerProperties, "topic5", 0);
// specify which offset to start from
Map<TopicPartition, Long> partitionOffsets = new HashMap<>();
partitionOffsets.put(new TopicPartition("topic5", 0), 2L);
this.reader.setPartitionOffsets(partitionOffsets);
this.reader.setPollTimeout(Duration.ofSeconds(1));
this.reader.open(new ExecutionContext());
String item = this.reader.read();
assertThat(item, is("val2"));
item = this.reader.read();
assertThat(item, is("val3"));
item = this.reader.read();
assertNull(item);
this.reader.close();
}
@Test
void testReadFromSinglePartitionFromTheOffsetStoredInKafka() throws Exception {
// first run: read a topic from the beginning
this.template.setDefaultTopic("topic6");
var futures = new ArrayList<CompletableFuture<?>>();
futures.add(this.template.sendDefault("val0")); // <-- offset 0
futures.add(this.template.sendDefault("val1")); // <-- offset 1
for (var future : futures) {
future.get();
}
this.reader = new KafkaItemReader<>(this.consumerProperties, "topic6", 0);
this.reader.setPollTimeout(Duration.ofSeconds(1));
this.reader.open(new ExecutionContext());
String item = this.reader.read();
assertThat(item, is("val0"));
item = this.reader.read();
assertThat(item, is("val1"));
item = this.reader.read();
assertNull(item);
this.reader.close();
// The offset stored in Kafka should be equal to 2 at this point
OffsetAndMetadata currentOffset = KafkaTestUtils.getCurrentOffset(embeddedKafka.getBrokersAsString(), "1",
"topic6", 0);
assertEquals(2, currentOffset.offset());
// second run (with same consumer group ID): new messages arrived since the last
// run.
this.template.sendDefault("val2"); // <-- offset 2
this.template.sendDefault("val3"); // <-- offset 3
this.reader = new KafkaItemReader<>(this.consumerProperties, "topic6", 0);
// Passing an empty map means the reader should start from the offset stored in
// Kafka (offset 2 in this case)
this.reader.setPartitionOffsets(new HashMap<>());
this.reader.setPollTimeout(Duration.ofSeconds(1));
this.reader.open(new ExecutionContext());
item = this.reader.read();
assertThat(item, is("val2"));
item = this.reader.read();
assertThat(item, is("val3"));
item = this.reader.read();
assertNull(item);
this.reader.close();
}
@Test
void testReadFromMultiplePartitions() throws ExecutionException, InterruptedException {
this.template.setDefaultTopic("topic2");
var futures = new ArrayList<CompletableFuture<?>>();
futures.add(this.template.sendDefault("val0"));
futures.add(this.template.sendDefault("val1"));
futures.add(this.template.sendDefault("val2"));
futures.add(this.template.sendDefault("val3"));
for (var future : futures) {
future.get();
}
this.reader = new KafkaItemReader<>(this.consumerProperties, "topic2", 0, 1);
this.reader.setPollTimeout(Duration.ofSeconds(1));
this.reader.open(new ExecutionContext());
List<String> items = new ArrayList<>();
items.add(this.reader.read());
items.add(this.reader.read());
items.add(this.reader.read());
items.add(this.reader.read());
assertThat(items, containsInAnyOrder("val0", "val1", "val2", "val3"));
String item = this.reader.read();
assertNull(item);
this.reader.close();
}
@Test
void testReadFromSinglePartitionAfterRestart() throws ExecutionException, InterruptedException {
this.template.setDefaultTopic("topic3");
var futures = new ArrayList<CompletableFuture<?>>();
futures.add(this.template.sendDefault("val0"));
futures.add(this.template.sendDefault("val1"));
futures.add(this.template.sendDefault("val2"));
futures.add(this.template.sendDefault("val3"));
futures.add(this.template.sendDefault("val4"));
for (var future : futures) {
future.get();
}
ExecutionContext executionContext = new ExecutionContext();
Map<TopicPartition, Long> offsets = new HashMap<>();
offsets.put(new TopicPartition("topic3", 0), 1L);
executionContext.put("topic.partition.offsets", offsets);
// topic3-0: val0, val1, val2, val3, val4
// ^
// |
// last committed offset = 1 (should restart from offset = 2)
this.reader = new KafkaItemReader<>(this.consumerProperties, "topic3", 0);
this.reader.setPollTimeout(Duration.ofSeconds(1));
this.reader.open(executionContext);
List<String> items = new ArrayList<>();
items.add(this.reader.read());
items.add(this.reader.read());
items.add(this.reader.read());
assertThat(items, containsInAnyOrder("val2", "val3", "val4"));
String item = this.reader.read();
assertNull(item);
this.reader.close();
}
@Test
void testReadFromMultiplePartitionsAfterRestart() throws ExecutionException, InterruptedException {
var futures = new ArrayList<CompletableFuture<?>>();
futures.add(this.template.send("topic4", 0, null, "val0"));
futures.add(this.template.send("topic4", 0, null, "val2"));
futures.add(this.template.send("topic4", 0, null, "val4"));
futures.add(this.template.send("topic4", 0, null, "val6"));
futures.add(this.template.send("topic4", 1, null, "val1"));
futures.add(this.template.send("topic4", 1, null, "val3"));
futures.add(this.template.send("topic4", 1, null, "val5"));
futures.add(this.template.send("topic4", 1, null, "val7"));
for (var future : futures) {
future.get();
}
ExecutionContext executionContext = new ExecutionContext();
Map<TopicPartition, Long> offsets = new HashMap<>();
offsets.put(new TopicPartition("topic4", 0), 1L);
offsets.put(new TopicPartition("topic4", 1), 2L);
executionContext.put("topic.partition.offsets", offsets);
// topic4-0: val0, val2, val4, val6
// ^
// |
// last committed offset = 1 (should restart from offset = 2)
// topic4-1: val1, val3, val5, val7
// ^
// |
// last committed offset = 2 (should restart from offset = 3)
this.reader = new KafkaItemReader<>(this.consumerProperties, "topic4", 0, 1);
this.reader.setPollTimeout(Duration.ofSeconds(1));
this.reader.open(executionContext);
List<String> items = new ArrayList<>();
items.add(this.reader.read());
items.add(this.reader.read());
items.add(this.reader.read());
assertThat(items, containsInAnyOrder("val4", "val6", "val7"));
String item = this.reader.read();
assertNull(item);
this.reader.close();
}
}

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@@ -1,5 +1,5 @@
/*
* Copyright 2019-2022 the original author or authors.
* Copyright 2019-2023 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.
@@ -17,81 +17,20 @@
package org.springframework.batch.item.kafka;
import java.time.Duration;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import org.apache.kafka.clients.admin.NewTopic;
import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.clients.consumer.OffsetAndMetadata;
import org.apache.kafka.common.TopicPartition;
import org.apache.kafka.common.serialization.StringDeserializer;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.springframework.batch.item.ExecutionContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.core.DefaultKafkaProducerFactory;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.kafka.core.ProducerFactory;
import org.springframework.kafka.test.EmbeddedKafkaBroker;
import org.springframework.kafka.test.context.EmbeddedKafka;
import org.springframework.kafka.test.utils.KafkaTestUtils;
import org.springframework.test.context.junit.jupiter.SpringExtension;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.containsInAnyOrder;
import static org.hamcrest.Matchers.is;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNull;
import static org.junit.jupiter.api.Assertions.assertThrows;
/**
* @author Mathieu Ouellet
* @author Mahmoud Ben Hassine
*/
@EmbeddedKafka
@ExtendWith(SpringExtension.class)
class KafkaItemReaderTests {
@Autowired
private EmbeddedKafkaBroker embeddedKafka;
private KafkaItemReader<String, String> reader;
private KafkaTemplate<String, String> template;
private Properties consumerProperties;
@BeforeAll
static void setUpTopics(@Autowired EmbeddedKafkaBroker embeddedKafka) {
embeddedKafka.addTopics(new NewTopic("topic1", 1, (short) 1), new NewTopic("topic2", 2, (short) 1),
new NewTopic("topic3", 1, (short) 1), new NewTopic("topic4", 2, (short) 1),
new NewTopic("topic5", 1, (short) 1), new NewTopic("topic6", 1, (short) 1));
}
@BeforeEach
void setUp() {
Map<String, Object> producerProperties = KafkaTestUtils.producerProps(embeddedKafka);
ProducerFactory<String, String> producerFactory = new DefaultKafkaProducerFactory<>(producerProperties);
this.template = new KafkaTemplate<>(producerFactory);
this.consumerProperties = new Properties();
this.consumerProperties.setProperty(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG,
embeddedKafka.getBrokersAsString());
this.consumerProperties.setProperty(ConsumerConfig.GROUP_ID_CONFIG, "1");
this.consumerProperties.setProperty(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG,
StringDeserializer.class.getName());
this.consumerProperties.setProperty(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG,
StringDeserializer.class.getName());
}
@Test
void testValidation() {
Exception exception = assertThrows(IllegalArgumentException.class,
@@ -103,7 +42,7 @@ class KafkaItemReaderTests {
assertEquals("bootstrap.servers property must be provided", exception.getMessage());
Properties consumerProperties = new Properties();
consumerProperties.put("bootstrap.servers", embeddedKafka);
consumerProperties.put("bootstrap.servers", "mockServer");
exception = assertThrows(IllegalArgumentException.class,
() -> new KafkaItemReader<>(consumerProperties, "topic", 0));
assertEquals("group.id property must be provided", exception.getMessage());
@@ -126,252 +65,16 @@ class KafkaItemReaderTests {
exception = assertThrows(Exception.class, () -> new KafkaItemReader<>(consumerProperties, "topic"));
assertEquals("At least one partition must be provided", exception.getMessage());
this.reader = new KafkaItemReader<>(consumerProperties, "topic", 0);
KafkaItemReader<String, String> reader = new KafkaItemReader<>(consumerProperties, "topic", 0);
exception = assertThrows(IllegalArgumentException.class, () -> this.reader.setPollTimeout(null));
exception = assertThrows(IllegalArgumentException.class, () -> reader.setPollTimeout(null));
assertEquals("pollTimeout must not be null", exception.getMessage());
exception = assertThrows(IllegalArgumentException.class, () -> this.reader.setPollTimeout(Duration.ZERO));
exception = assertThrows(IllegalArgumentException.class, () -> reader.setPollTimeout(Duration.ZERO));
assertEquals("pollTimeout must not be zero", exception.getMessage());
exception = assertThrows(IllegalArgumentException.class,
() -> this.reader.setPollTimeout(Duration.ofSeconds(-1)));
exception = assertThrows(IllegalArgumentException.class, () -> reader.setPollTimeout(Duration.ofSeconds(-1)));
assertEquals("pollTimeout must not be negative", exception.getMessage());
}
@Test
void testReadFromSinglePartition() throws ExecutionException, InterruptedException {
this.template.setDefaultTopic("topic1");
var futures = new ArrayList<CompletableFuture<?>>();
futures.add(this.template.sendDefault("val0"));
futures.add(this.template.sendDefault("val1"));
futures.add(this.template.sendDefault("val2"));
futures.add(this.template.sendDefault("val3"));
for (var future : futures) {
future.get();
}
this.reader = new KafkaItemReader<>(this.consumerProperties, "topic1", 0);
this.reader.setPollTimeout(Duration.ofSeconds(1));
this.reader.open(new ExecutionContext());
String item = this.reader.read();
assertThat(item, is("val0"));
item = this.reader.read();
assertThat(item, is("val1"));
item = this.reader.read();
assertThat(item, is("val2"));
item = this.reader.read();
assertThat(item, is("val3"));
item = this.reader.read();
assertNull(item);
this.reader.close();
}
@Test
void testReadFromSinglePartitionFromCustomOffset() throws ExecutionException, InterruptedException {
this.template.setDefaultTopic("topic5");
var futures = new ArrayList<CompletableFuture<?>>();
futures.add(this.template.sendDefault("val0")); // <-- offset 0
futures.add(this.template.sendDefault("val1")); // <-- offset 1
futures.add(this.template.sendDefault("val2")); // <-- offset 2
futures.add(this.template.sendDefault("val3")); // <-- offset 3
for (var future : futures) {
future.get();
}
this.reader = new KafkaItemReader<>(this.consumerProperties, "topic5", 0);
// specify which offset to start from
Map<TopicPartition, Long> partitionOffsets = new HashMap<>();
partitionOffsets.put(new TopicPartition("topic5", 0), 2L);
this.reader.setPartitionOffsets(partitionOffsets);
this.reader.setPollTimeout(Duration.ofSeconds(1));
this.reader.open(new ExecutionContext());
String item = this.reader.read();
assertThat(item, is("val2"));
item = this.reader.read();
assertThat(item, is("val3"));
item = this.reader.read();
assertNull(item);
this.reader.close();
}
@Test
void testReadFromSinglePartitionFromTheOffsetStoredInKafka() throws Exception {
// first run: read a topic from the beginning
this.template.setDefaultTopic("topic6");
var futures = new ArrayList<CompletableFuture<?>>();
futures.add(this.template.sendDefault("val0")); // <-- offset 0
futures.add(this.template.sendDefault("val1")); // <-- offset 1
for (var future : futures) {
future.get();
}
this.reader = new KafkaItemReader<>(this.consumerProperties, "topic6", 0);
this.reader.setPollTimeout(Duration.ofSeconds(1));
this.reader.open(new ExecutionContext());
String item = this.reader.read();
assertThat(item, is("val0"));
item = this.reader.read();
assertThat(item, is("val1"));
item = this.reader.read();
assertNull(item);
this.reader.close();
// The offset stored in Kafka should be equal to 2 at this point
OffsetAndMetadata currentOffset = KafkaTestUtils.getCurrentOffset(embeddedKafka.getBrokersAsString(), "1",
"topic6", 0);
assertEquals(2, currentOffset.offset());
// second run (with same consumer group ID): new messages arrived since the last
// run.
this.template.sendDefault("val2"); // <-- offset 2
this.template.sendDefault("val3"); // <-- offset 3
this.reader = new KafkaItemReader<>(this.consumerProperties, "topic6", 0);
// Passing an empty map means the reader should start from the offset stored in
// Kafka (offset 2 in this case)
this.reader.setPartitionOffsets(new HashMap<>());
this.reader.setPollTimeout(Duration.ofSeconds(1));
this.reader.open(new ExecutionContext());
item = this.reader.read();
assertThat(item, is("val2"));
item = this.reader.read();
assertThat(item, is("val3"));
item = this.reader.read();
assertNull(item);
this.reader.close();
}
@Test
void testReadFromMultiplePartitions() throws ExecutionException, InterruptedException {
this.template.setDefaultTopic("topic2");
var futures = new ArrayList<CompletableFuture<?>>();
futures.add(this.template.sendDefault("val0"));
futures.add(this.template.sendDefault("val1"));
futures.add(this.template.sendDefault("val2"));
futures.add(this.template.sendDefault("val3"));
for (var future : futures) {
future.get();
}
this.reader = new KafkaItemReader<>(this.consumerProperties, "topic2", 0, 1);
this.reader.setPollTimeout(Duration.ofSeconds(1));
this.reader.open(new ExecutionContext());
List<String> items = new ArrayList<>();
items.add(this.reader.read());
items.add(this.reader.read());
items.add(this.reader.read());
items.add(this.reader.read());
assertThat(items, containsInAnyOrder("val0", "val1", "val2", "val3"));
String item = this.reader.read();
assertNull(item);
this.reader.close();
}
@Test
void testReadFromSinglePartitionAfterRestart() throws ExecutionException, InterruptedException {
this.template.setDefaultTopic("topic3");
var futures = new ArrayList<CompletableFuture<?>>();
futures.add(this.template.sendDefault("val0"));
futures.add(this.template.sendDefault("val1"));
futures.add(this.template.sendDefault("val2"));
futures.add(this.template.sendDefault("val3"));
futures.add(this.template.sendDefault("val4"));
for (var future : futures) {
future.get();
}
ExecutionContext executionContext = new ExecutionContext();
Map<TopicPartition, Long> offsets = new HashMap<>();
offsets.put(new TopicPartition("topic3", 0), 1L);
executionContext.put("topic.partition.offsets", offsets);
// topic3-0: val0, val1, val2, val3, val4
// ^
// |
// last committed offset = 1 (should restart from offset = 2)
this.reader = new KafkaItemReader<>(this.consumerProperties, "topic3", 0);
this.reader.setPollTimeout(Duration.ofSeconds(1));
this.reader.open(executionContext);
List<String> items = new ArrayList<>();
items.add(this.reader.read());
items.add(this.reader.read());
items.add(this.reader.read());
assertThat(items, containsInAnyOrder("val2", "val3", "val4"));
String item = this.reader.read();
assertNull(item);
this.reader.close();
}
@Test
void testReadFromMultiplePartitionsAfterRestart() throws ExecutionException, InterruptedException {
var futures = new ArrayList<CompletableFuture<?>>();
futures.add(this.template.send("topic4", 0, null, "val0"));
futures.add(this.template.send("topic4", 0, null, "val2"));
futures.add(this.template.send("topic4", 0, null, "val4"));
futures.add(this.template.send("topic4", 0, null, "val6"));
futures.add(this.template.send("topic4", 1, null, "val1"));
futures.add(this.template.send("topic4", 1, null, "val3"));
futures.add(this.template.send("topic4", 1, null, "val5"));
futures.add(this.template.send("topic4", 1, null, "val7"));
for (var future : futures) {
future.get();
}
ExecutionContext executionContext = new ExecutionContext();
Map<TopicPartition, Long> offsets = new HashMap<>();
offsets.put(new TopicPartition("topic4", 0), 1L);
offsets.put(new TopicPartition("topic4", 1), 2L);
executionContext.put("topic.partition.offsets", offsets);
// topic4-0: val0, val2, val4, val6
// ^
// |
// last committed offset = 1 (should restart from offset = 2)
// topic4-1: val1, val3, val5, val7
// ^
// |
// last committed offset = 2 (should restart from offset = 3)
this.reader = new KafkaItemReader<>(this.consumerProperties, "topic4", 0, 1);
this.reader.setPollTimeout(Duration.ofSeconds(1));
this.reader.open(executionContext);
List<String> items = new ArrayList<>();
items.add(this.reader.read());
items.add(this.reader.read());
items.add(this.reader.read());
assertThat(items, containsInAnyOrder("val4", "val6", "val7"));
String item = this.reader.read();
assertNull(item);
this.reader.close();
}
}