MINOR: Fix a number of warnings in clients test (#8073)

Reviewers: Ismael Juma <ismael@juma.me.uk>, Andrew Choi <li_andchoi@microsoft.com>

clients/src/test/java/org/apache/kafka/clients/consumer/ConsumerConfigTest.java

@@ -29,8 +29,8 @@ import static org.junit.Assert.assertEquals;
 
 public class ConsumerConfigTest {
 
-    private final Deserializer keyDeserializer = new ByteArrayDeserializer();
-    private final Deserializer valueDeserializer = new StringDeserializer();
+    private final Deserializer<byte[]> keyDeserializer = new ByteArrayDeserializer();
+    private final Deserializer<String> valueDeserializer = new StringDeserializer();
     private final String keyDeserializerClassName = keyDeserializer.getClass().getName();
     private final String valueDeserializerClassName = valueDeserializer.getClass().getName();
     private final Object keyDeserializerClass = keyDeserializer.getClass();

clients/src/test/java/org/apache/kafka/clients/consumer/internals/ConsumerCoordinatorTest.java

@@ -53,7 +53,6 @@ import org.apache.kafka.common.message.OffsetCommitResponseData;
 import org.apache.kafka.common.message.SyncGroupResponseData;
 import org.apache.kafka.common.metrics.KafkaMetric;
 import org.apache.kafka.common.metrics.Metrics;
-import org.apache.kafka.common.metrics.Sensor;
 import org.apache.kafka.common.protocol.Errors;
 import org.apache.kafka.common.record.RecordBatch;
 import org.apache.kafka.common.requests.AbstractRequest;
@@ -252,10 +251,6 @@ public class ConsumerCoordinatorTest {
         return metrics.metrics().get(metrics.metricName(name, "consumer" + groupId + "-coordinator-metrics"));
     }
 
-    private Sensor getSensor(final String name) {
-        return metrics.sensor(name);
-    }
-
     @Test
     public void testSelectRebalanceProtcol() {
         List<ConsumerPartitionAssignor> assignors = new ArrayList<>();

clients/src/test/java/org/apache/kafka/clients/consumer/internals/FetcherTest.java

@@ -134,7 +134,6 @@ import static org.junit.Assert.fail;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.spy;
 
-@SuppressWarnings("deprecation")
 public class FetcherTest {
     private static final double EPSILON = 0.0001;
 
@@ -2011,7 +2010,7 @@ public class FetcherTest {
             ClientRequest request = client.newClientRequest(node.idString(), builder, time.milliseconds(), true);
             client.send(request, time.milliseconds());
             client.poll(1, time.milliseconds());
-            FetchResponse response = fullFetchResponse(tp0, nextRecords, Errors.NONE, i, throttleTimeMs);
+            FetchResponse<MemoryRecords> response = fullFetchResponse(tp0, nextRecords, Errors.NONE, i, throttleTimeMs);
             buffer = response.serialize(ApiKeys.FETCH,
                     ApiKeys.FETCH.latestVersion(),
                     request.correlationId());
@@ -3104,7 +3103,7 @@ public class FetcherTest {
                 2, 0L, null, this.records));
         partitions1.put(tp1, new FetchResponse.PartitionData<>(Errors.NONE, 100L,
                 FetchResponse.INVALID_LAST_STABLE_OFFSET, 0L, null, emptyRecords));
-        FetchResponse resp1 = new FetchResponse<>(Errors.NONE, partitions1, 0, 123);
+        FetchResponse<MemoryRecords> resp1 = new FetchResponse<>(Errors.NONE, partitions1, 0, 123);
         client.prepareResponse(resp1);
         assertEquals(1, fetcher.sendFetches());
         assertFalse(fetcher.hasCompletedFetches());
@@ -3130,7 +3129,7 @@ public class FetcherTest {
 
         // The second response contains no new records.
         LinkedHashMap<TopicPartition, FetchResponse.PartitionData<MemoryRecords>> partitions2 = new LinkedHashMap<>();
-        FetchResponse resp2 = new FetchResponse<>(Errors.NONE, partitions2, 0, 123);
+        FetchResponse<MemoryRecords> resp2 = new FetchResponse<>(Errors.NONE, partitions2, 0, 123);
         client.prepareResponse(resp2);
         assertEquals(1, fetcher.sendFetches());
         consumerClient.poll(time.timer(0));
@@ -3143,7 +3142,7 @@ public class FetcherTest {
         LinkedHashMap<TopicPartition, FetchResponse.PartitionData<MemoryRecords>> partitions3 = new LinkedHashMap<>();
         partitions3.put(tp0, new FetchResponse.PartitionData<>(Errors.NONE, 100L,
                 4, 0L, null, this.nextRecords));
-        FetchResponse resp3 = new FetchResponse<>(Errors.NONE, partitions3, 0, 123);
+        FetchResponse<MemoryRecords> resp3 = new FetchResponse<>(Errors.NONE, partitions3, 0, 123);
         client.prepareResponse(resp3);
         assertEquals(1, fetcher.sendFetches());
         consumerClient.poll(time.timer(0));
@@ -3202,7 +3201,7 @@ public class FetcherTest {
                         }
 
                         @Override
-                        public boolean handleResponse(FetchResponse response) {
+                        public boolean handleResponse(FetchResponse<?> response) {
                             verifySessionPartitions();
                             return handler.handleResponse(response);
                         }

clients/src/test/java/org/apache/kafka/clients/consumer/internals/PartitionAssignorAdapterTest.java

@@ -101,7 +101,6 @@ public class PartitionAssignorAdapterTest {
     }
 
     @Test
-    @SuppressWarnings("deprecation")
     public void testOnAssignment() {
         OldPartitionAssignor oldAssignor = new OldPartitionAssignor();
         ConsumerPartitionAssignor adaptedAssignor = new PartitionAssignorAdapter(oldAssignor);

clients/src/test/java/org/apache/kafka/clients/producer/KafkaProducerTest.java

@@ -133,8 +133,8 @@ public class KafkaProducerTest {
         Properties props = new Properties();
         props.setProperty(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9999");
         props.setProperty(ProducerConfig.TRANSACTIONAL_ID_CONFIG, "transactionalId");
-        props.setProperty(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, new StringSerializer().getClass().getName());
-        props.setProperty(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, new StringSerializer().getClass().getName());
+        props.setProperty(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+        props.setProperty(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
 
         ProducerConfig config = new ProducerConfig(props);
         assertTrue(config.getBoolean(ProducerConfig.ENABLE_IDEMPOTENCE_CONFIG));
@@ -457,7 +457,7 @@ public class KafkaProducerTest {
 
         // Four request updates where the topic isn't present, at which point the timeout expires and a
         // TimeoutException is thrown
-        Future future = producer.send(record);
+        Future<RecordMetadata> future = producer.send(record);
         verify(metadata, times(4)).requestUpdateForTopic(topic);
         verify(metadata, times(4)).awaitUpdate(anyInt(), anyLong());
         verify(metadata, times(5)).fetch();
@@ -533,7 +533,7 @@ public class KafkaProducerTest {
 
         // Four request updates where the requested partition is out of range, at which point the timeout expires
         // and a TimeoutException is thrown
-        Future future = producer.send(record);
+        Future<RecordMetadata> future = producer.send(record);
         verify(metadata, times(4)).requestUpdateForTopic(topic);
         verify(metadata, times(4)).awaitUpdate(anyInt(), anyLong());
         verify(metadata, times(5)).fetch();
@@ -644,9 +644,7 @@ public class KafkaProducerTest {
     private <T extends Serializer<String>> void doTestHeaders(Class<T> serializerClassToMock) {
         Map<String, Object> configs = new HashMap<>();
         configs.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9999");
-        @SuppressWarnings("unchecked") // it is safe to suppress, since this is a mock class
         Serializer<String> keySerializer = mock(serializerClassToMock);
-        @SuppressWarnings("unchecked")
         Serializer<String> valueSerializer = mock(serializerClassToMock);
 
         long nowMs = Time.SYSTEM.milliseconds();
@@ -689,7 +687,7 @@ public class KafkaProducerTest {
     public void closeShouldBeIdempotent() {
         Properties producerProps = new Properties();
         producerProps.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9000");
-        Producer producer = new KafkaProducer<>(producerProps, new ByteArraySerializer(), new ByteArraySerializer());
+        Producer<byte[], byte[]> producer = new KafkaProducer<>(producerProps, new ByteArraySerializer(), new ByteArraySerializer());
         producer.close();
         producer.close();
     }
@@ -698,12 +696,12 @@ public class KafkaProducerTest {
     public void testMetricConfigRecordingLevel() {
         Properties props = new Properties();
         props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9000");
-        try (KafkaProducer producer = new KafkaProducer<>(props, new ByteArraySerializer(), new ByteArraySerializer())) {
+        try (KafkaProducer<byte[], byte[]> producer = new KafkaProducer<>(props, new ByteArraySerializer(), new ByteArraySerializer())) {
             assertEquals(Sensor.RecordingLevel.INFO, producer.metrics.config().recordLevel());
         }
 
         props.put(ProducerConfig.METRICS_RECORDING_LEVEL_CONFIG, "DEBUG");
-        try (KafkaProducer producer = new KafkaProducer<>(props, new ByteArraySerializer(), new ByteArraySerializer())) {
+        try (KafkaProducer<byte[], byte[]> producer = new KafkaProducer<>(props, new ByteArraySerializer(), new ByteArraySerializer())) {
             assertEquals(Sensor.RecordingLevel.DEBUG, producer.metrics.config().recordLevel());
         }
     }

clients/src/test/java/org/apache/kafka/common/config/AbstractConfigTest.java

@@ -407,7 +407,7 @@ public class AbstractConfigTest {
             "org.apache.kafka.common.config.provider.InvalidConfigProvider");
         props.put("testKey", "${test:/foo/bar/testpath:testKey}");
         try {
-            TestIndirectConfigResolution config = new TestIndirectConfigResolution(props);
+            new TestIndirectConfigResolution(props);
             fail("Expected a config exception due to invalid props :" + props);
         } catch (KafkaException e) {
             // this is good

clients/src/test/java/org/apache/kafka/common/metrics/stats/FrequenciesTest.java

@@ -101,7 +101,6 @@ public class FrequenciesTest {
     }
 
     @Test
-    @SuppressWarnings("deprecation")
     public void testUseWithMetrics() {
         MetricName name1 = name("1");
         MetricName name2 = name("2");

clients/src/test/java/org/apache/kafka/common/network/SslTransportLayerTest.java

@@ -277,7 +277,6 @@ public class SslTransportLayerTest {
         sslServerConfigs = getTrustingConfig(serverCertStores, clientCertStores);
         sslClientConfigs = getTrustingConfig(clientCertStores, serverCertStores);
 
-        SecurityProtocol securityProtocol = SecurityProtocol.SSL;
         server = createEchoServer(SecurityProtocol.SSL);
         InetSocketAddress addr = new InetSocketAddress("localhost", server.port());
 

clients/src/test/java/org/apache/kafka/common/protocol/ErrorsTest.java

@@ -40,7 +40,7 @@ public class ErrorsTest {
 
     @Test
     public void testUniqueExceptions() {
-        Set<Class> exceptionSet = new HashSet<>();
+        Set<Class<?>> exceptionSet = new HashSet<>();
         for (Errors error : Errors.values()) {
             if (error != Errors.NONE)
                 exceptionSet.add(error.exception().getClass());

clients/src/test/java/org/apache/kafka/common/requests/RequestResponseTest.java

@@ -642,7 +642,7 @@ public class RequestResponseTest {
                 6, FetchResponse.INVALID_LOG_START_OFFSET, Optional.empty(), emptyList(), records));
 
         FetchResponse<MemoryRecords> response = new FetchResponse<>(Errors.NONE, responseData, 10, INVALID_SESSION_ID);
-        FetchResponse deserialized = FetchResponse.parse(toBuffer(response.toStruct((short) 4)), (short) 4);
+        FetchResponse<MemoryRecords> deserialized = FetchResponse.parse(toBuffer(response.toStruct((short) 4)), (short) 4);
         assertEquals(responseData, deserialized.responseData());
     }
 
@@ -656,7 +656,7 @@ public class RequestResponseTest {
         }
     }
 
-    private void verifyFetchResponseFullWrite(short apiVersion, FetchResponse fetchResponse) throws Exception {
+    private void verifyFetchResponseFullWrite(short apiVersion, FetchResponse<MemoryRecords> fetchResponse) throws Exception {
         int correlationId = 15;
 
         short responseHeaderVersion = FETCH.responseHeaderVersion(apiVersion);
@@ -1038,14 +1038,6 @@ public class RequestResponseTest {
             .setProtocolName("range")    // Added in v5 but ignorable
             .setAssignments(assignments);
 
-        JoinGroupRequestData.JoinGroupRequestProtocolCollection protocols =
-            new JoinGroupRequestData.JoinGroupRequestProtocolCollection(
-                Collections.singleton(
-                    new JoinGroupRequestData.JoinGroupRequestProtocol()
-                        .setName("consumer-range")
-                        .setMetadata(new byte[0])).iterator()
-            );
-
         // v3 and above could set group instance id
         if (version >= 3)
             data.setGroupInstanceId("groupInstanceId");

clients/src/test/java/org/apache/kafka/common/security/authenticator/SaslServerAuthenticatorTest.java

@@ -31,7 +31,6 @@ import org.apache.kafka.common.security.auth.AuthenticateCallbackHandler;
 import org.apache.kafka.common.security.auth.SecurityProtocol;
 import org.apache.kafka.common.protocol.types.Struct;
 import org.apache.kafka.common.requests.RequestHeader;
-import org.apache.kafka.common.security.JaasContext;
 import org.apache.kafka.common.security.plain.PlainLoginModule;
 import org.apache.kafka.common.utils.AppInfoParser;
 import org.apache.kafka.common.utils.Time;
@@ -152,8 +151,6 @@ public class SaslServerAuthenticatorTest {
                                                        String mechanism, ChannelMetadataRegistry metadataRegistry) throws IOException {
         TestJaasConfig jaasConfig = new TestJaasConfig();
         jaasConfig.addEntry("jaasContext", PlainLoginModule.class.getName(), new HashMap<String, Object>());
-        Map<String, JaasContext> jaasContexts = Collections.singletonMap(mechanism,
-                new JaasContext("jaasContext", JaasContext.Type.SERVER, jaasConfig, null));
         Map<String, Subject> subjects = Collections.singletonMap(mechanism, new Subject());
         Map<String, AuthenticateCallbackHandler> callbackHandlers = Collections.singletonMap(
                 mechanism, new SaslServerCallbackHandler());

clients/src/test/java/org/apache/kafka/common/security/ssl/SslFactoryTest.java

@@ -376,15 +376,6 @@ public class SslFactoryTest {
         );
     }
 
-    private SslEngineBuilder.SecurityStore sslTrustStore(Map<String, Object> sslConfig) {
-        return new SslEngineBuilder.SecurityStore(
-                (String) sslConfig.get(SslConfigs.SSL_TRUSTSTORE_TYPE_CONFIG),
-                (String) sslConfig.get(SslConfigs.SSL_TRUSTSTORE_LOCATION_CONFIG),
-                (Password) sslConfig.get(SslConfigs.SSL_TRUSTSTORE_PASSWORD_CONFIG),
-                null
-        );
-    }
-
     private TestSslUtils.SslConfigsBuilder sslConfigsBuilder(Mode mode) {
         return new TestSslUtils.SslConfigsBuilder(mode).tlsProtocol(tlsProtocol);
     }

clients/src/test/java/org/apache/kafka/common/utils/UtilsTest.java

@@ -72,8 +72,8 @@ public class UtilsTest {
         cases.put("lkjh234lh9fiuh90y23oiuhsafujhadof229phr9h19h89h8".getBytes(), -58897971);
         cases.put(new byte[]{'a', 'b', 'c'}, 479470107);
 
-        for (Map.Entry c : cases.entrySet()) {
-            assertEquals((int) c.getValue(), murmur2((byte[]) c.getKey()));
+        for (Map.Entry<byte[], Integer> c : cases.entrySet()) {
+            assertEquals(c.getValue().intValue(), murmur2(c.getKey()));
         }
     }
 

clients/src/test/java/org/apache/kafka/test/TestUtils.java

@@ -276,8 +276,8 @@ public class TestUtils {
     }
 
     public static Properties producerConfig(final String bootstrapServers,
-                                            final Class keySerializer,
-                                            final Class valueSerializer,
+                                            final Class<?> keySerializer,
+                                            final Class<?> valueSerializer,
                                             final Properties additional) {
         final Properties properties = new Properties();
         properties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
@@ -288,14 +288,14 @@ public class TestUtils {
         return properties;
     }
 
-    public static Properties producerConfig(final String bootstrapServers, final Class keySerializer, final Class valueSerializer) {
+    public static Properties producerConfig(final String bootstrapServers, final Class<?> keySerializer, final Class<?> valueSerializer) {
         return producerConfig(bootstrapServers, keySerializer, valueSerializer, new Properties());
     }
 
     public static Properties consumerConfig(final String bootstrapServers,
                                             final String groupId,
-                                            final Class keyDeserializer,
-                                            final Class valueDeserializer,
+                                            final Class<?> keyDeserializer,
+                                            final Class<?> valueDeserializer,
                                             final Properties additional) {
 
         final Properties consumerConfig = new Properties();
@@ -310,8 +310,8 @@ public class TestUtils {
 
     public static Properties consumerConfig(final String bootstrapServers,
                                             final String groupId,
-                                            final Class keyDeserializer,
-                                            final Class valueDeserializer) {
+                                            final Class<?> keyDeserializer,
+                                            final Class<?> valueDeserializer) {
         return consumerConfig(bootstrapServers,
             groupId,
             keyDeserializer,
@@ -322,7 +322,7 @@ public class TestUtils {
     /**
      * returns consumer config with random UUID for the Group ID
      */
-    public static Properties consumerConfig(final String bootstrapServers, final Class keyDeserializer, final Class valueDeserializer) {
+    public static Properties consumerConfig(final String bootstrapServers, final Class<?> keyDeserializer, final Class<?> valueDeserializer) {
         return consumerConfig(bootstrapServers,
             UUID.randomUUID().toString(),
             keyDeserializer,