Add pull API

java/client-apis/src/main/java/org/apache/rocketmq/client/apis/consumer/PullConsumer.java

@@ -0,0 +1,61 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.apache.rocketmq.client.apis.consumer;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.time.Duration;
+import java.util.Collection;
+import java.util.List;
+import java.util.Optional;
+import org.apache.rocketmq.client.apis.ClientException;
+import org.apache.rocketmq.client.apis.message.MessageQueue;
+import org.apache.rocketmq.client.apis.message.MessageView;
+
+public interface PullConsumer extends Closeable {
+    String getConsumerGroup();
+
+    void registerMessageQueueChangeListenerByTopic(String topic, TopicMessageQueueChangeListener listener);
+
+    Collection<MessageQueue> fetchMessageQueues(String topic) throws ClientException;
+
+    PullConsumer subscribe(String topic, FilterExpression filterExpression) throws ClientException;
+
+    PullConsumer unsubscribe(String topic);
+
+    void assign(Collection<MessageQueue> messageQueues);
+
+    List<MessageView> poll(Duration timeout);
+
+    void seek(MessageQueue messageQueue, long offset);
+
+    void pause(Collection<MessageQueue> messageQueues);
+
+    void resume(Collection<MessageQueue> messageQueues);
+
+    Optional<Long> committed(MessageQueue messageQueue);
+
+    void commit();
+
+    void seekToBegin(MessageQueue messageQueue) throws ClientException;
+
+    void seekToEnd(MessageQueue messageQueue) throws ClientException;
+
+    @Override
+    void close() throws IOException;
+}

java/client-apis/src/main/java/org/apache/rocketmq/client/apis/consumer/PullConsumerBuilder.java

@@ -0,0 +1,82 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.apache.rocketmq.client.apis.consumer;
+
+import java.time.Duration;
+import org.apache.rocketmq.client.apis.ClientConfiguration;
+import org.apache.rocketmq.client.apis.ClientException;
+
+public interface PullConsumerBuilder {
+    /**
+     * Set the client configuration for the consumer.
+     *
+     * @param clientConfiguration client's configuration.
+     * @return the consumer builder instance.
+     */
+    PullConsumerBuilder setClientConfiguration(ClientConfiguration clientConfiguration);
+
+    /**
+     * Set the load balancing group for the consumer.
+     *
+     * @param consumerGroup consumer load balancing group.
+     * @return the consumer builder instance.
+     */
+    PullConsumerBuilder setConsumerGroup(String consumerGroup);
+
+    /**
+     * Automate the consumer's offset commit.
+     *
+     * @return the consumer builder instance.
+     */
+    PullConsumerBuilder enableAutoCommit(boolean enable);
+
+    /**
+     * Set the consumer's offset commit interval if auto commit is enabled.
+     *
+     * @param duration offset commit interval
+     * @return the consumer builder instance.
+     */
+    PullConsumerBuilder setAutoCommitInterval(Duration duration);
+
+    /**
+     * Set the maximum number of messages cached locally.
+     *
+     * @param count message count.
+     * @return the consumer builder instance.
+     */
+    PullConsumerBuilder setMaxCacheMessageCountEachQueue(int count);
+
+    /**
+     * Set the maximum bytes of messages cached locally.
+     *
+     * @param bytes message size.
+     * @return the consumer builder instance.
+     */
+    PullConsumerBuilder setMaxCacheMessageSizeInBytesEachQueue(int bytes);
+
+    /**
+     * Finalize the build of {@link PullConsumer} and start.
+     *
+     * <p>This method will block until the pull consumer starts successfully.
+     *
+     * <p>Especially, if this method is invoked more than once, different pull consumer will be created and started.
+     *
+     * @return the pull consumer instance.
+     */
+    PullConsumer build() throws ClientException;
+}

java/client-apis/src/main/java/org/apache/rocketmq/client/apis/consumer/PushConsumerBuilder.java

@@ -86,7 +86,7 @@ public interface PushConsumerBuilder {
      *
      * <p>This method will block until the push consumer starts successfully.
      *
-     * <p>Especially, if this method is invoked more than once, different push consumers will be created and started.
+     * <p>Especially, if this method is invoked more than once, different push consumer will be created and started.
      *
      * @return the push consumer instance.
      */

java/client-apis/src/main/java/org/apache/rocketmq/client/apis/consumer/TopicMessageQueueChangeListener.java

@@ -0,0 +1,32 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.apache.rocketmq.client.apis.consumer;
+
+import java.util.Set;
+import org.apache.rocketmq.client.apis.message.MessageQueue;
+
+public interface TopicMessageQueueChangeListener {
+    /**
+     * This method will be invoked in the condition of queue numbers changed, These scenarios occur when the topic is
+     * expanded or shrunk.
+     *
+     * @param topic         the topic to listen.
+     * @param messageQueues
+     */
+    void onChanged(String topic, Set<MessageQueue> messageQueues);
+}

java/client-apis/src/main/java/org/apache/rocketmq/client/apis/message/MessageQueue.java

@@ -0,0 +1,24 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.apache.rocketmq.client.apis.message;
+
+public interface MessageQueue {
+    String getTopic();
+
+    String getId();
+}