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class="breadcrumbHomeIcon_YNFT"><path d="M10 19v-5h4v5c0 .55.45 1 1 1h3c.55 0 1-.45 1-1v-7h1.7c.46 0 .68-.57.33-.87L12.67 3.6c-.38-.34-.96-.34-1.34 0l-8.36 7.53c-.34.3-.13.87.33.87H5v7c0 .55.45 1 1 1h3c.55 0 1-.45 1-1z" fill="currentColor"></path></svg></a></li><li class="breadcrumbs__item"><span class="breadcrumbs__link">Consumer</span><meta itemprop="position" content="1"></li><li itemscope="" itemprop="itemListElement" itemtype="https://schema.org/ListItem" class="breadcrumbs__item breadcrumbs__item--active"><span class="breadcrumbs__link" itemprop="name">Pull Consumer</span><meta itemprop="position" content="2"></li></ul></nav><span class="theme-doc-version-badge badge badge--secondary">Version: 4.x</span><div class="tocCollapsible_ETCw theme-doc-toc-mobile tocMobile_ITEo"><button type="button" class="clean-btn tocCollapsibleButton_TO0P">On this page</button></div><div class="theme-doc-markdown markdown"><h1>Pull Consumer</h1><p>There are two kinds of Pull methods in RocketMQ. <code>Pull Consumer</code> is the more primitive one, which does not provide related subscription methods, The queue should be specified to pull while calling the pull method, and it needs to update the offset itself. The other one is the <code>Lite Pull Consumer</code>, which provides Subscribe and Assign mode, making it more convenient to use.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="pull-consumer-1">Pull Consumer<a href="#pull-consumer-1" class="hash-link" aria-label="Direct link to heading" title="Direct link to heading"></a></h2><p>The Pull Consumer example is as follows:</p><div class="language-java codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#393A34;--prism-background-color:#f6f8fa"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-java codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#393A34"><span class="token plain">public class PullConsumerTest {</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> public static void main(String[] args) throws MQClientException {</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> DefaultMQPullConsumer consumer = new DefaultMQPullConsumer("please_rename_unique_group_name_5");</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> consumer.setNamesrvAddr("127.0.0.1:9876");</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> consumer.start();</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> try {</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> MessageQueue mq = new MessageQueue();</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> mq.setQueueId(0);</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> mq.setTopic("TopicTest");</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> mq.setBrokerName("jinrongtong-MacBook-Pro.local");</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> long offset = 26;</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> PullResult pullResult = consumer.pull(mq, "*", offset, 32);</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> if (pullResult.getPullStatus().equals(PullStatus.FOUND)) {</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> System.out.printf("%s%n", pullResult.getMsgFoundList());</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> consumer.updateConsumeOffset(mq, pullResult.getNextBeginOffset());</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> }</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> } catch (Exception e) {</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> e.printStackTrace();</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> }</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> consumer.shutdown();</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> }</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg viewBox="0 0 24 24" class="copyButtonIcon_y97N"><path fill="currentColor" d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg viewBox="0 0 24 24" class="copyButtonSuccessIcon_LjdS"><path fill="currentColor" d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>First, the <code>DefaultMQPullConsumer</code> should be initialized and started, then constructs the queue <code>MessageQueue</code> to be pulled. Besides constructing it, <code>fetchSubscribeMessageQueues</code> method can also be called as shown below to get all the queues of a certain Topic and pull from the selected queue.</p><div class="language-java codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#393A34;--prism-background-color:#f6f8fa"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-java codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#393A34"><span class="token plain">Set<MessageQueue> queueSet = consumer.fetchSubscribeMessageQueues("TopicTest");</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg viewBox="0 0 24 24" class="copyButtonIcon_y97N"><path fill="currentColor" d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg viewBox="0 0 24 24" class="copyButtonSuccessIcon_LjdS"><path fill="currentColor" d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>After finding or constructing the queue, call the pull method to start pulling. The parameters such as the queue to be pulled, the filter expression, the offset to be pulled, and the maximum number of messages to be pulled should be passed in it. The <code>PullResult</code> will be returned after the operation is completed, and the PullStatus in the PullResult indicates the result status, as shown below:</p><div class="language-java codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#393A34;--prism-background-color:#f6f8fa"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-java codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#393A34"><span class="token plain">public enum PullStatus {</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> /**</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> * Founded</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> */</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> FOUND,</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> /**</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> * No new message can be pull</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> */</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> NO_NEW_MSG,</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> /**</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> * Filtering results can not match</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> */</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> NO_MATCHED_MSG,</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> /**</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> * Illegal offset,may be too big or too small</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> */</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> OFFSET_ILLEGAL</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg viewBox="0 0 24 24" class="copyButtonIcon_y97N"><path fill="currentColor" d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg viewBox="0 0 24 24" class="copyButtonSuccessIcon_LjdS"><path fill="currentColor" d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>FOUND means the message was pulled, NO_NEW_MSG means no new message was found, NO_MATCHED_MSG means no matching message, OFFSET_ILLEGAL means the incoming pull offset are illegal and may be large or small. If the pull status is FOUND, we can get the list of pulled messages via the <code>getMsgFoundList</code> method of <code>PullResult</code>. Finally, if the consumption is complete, the consumption offset are updated via the <code>updateConsumeOffset</code> method.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="lite-pull-consumer">Lite Pull Consumer<a href="#lite-pull-consumer" class="hash-link" aria-label="Direct link to heading" title="Direct link to heading"></a></h2><p>Lite Pull Consumer is a Pull Consumer introduced in RocketMQ 4.6.0, which is simpler to use than the original Pull Consumer and provides two modes, Subscribe and Assign. The Subscribe mode example is as follows:</p><div class="language-java codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#393A34;--prism-background-color:#f6f8fa"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-java codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#393A34"><span class="token plain">public class LitePullConsumerSubscribe {</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> public static volatile boolean running = true;</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> public static void main(String[] args) throws Exception {</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> DefaultLitePullConsumer litePullConsumer = new DefaultLitePullConsumer("lite_pull_consumer_test");</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> litePullConsumer.subscribe("TopicTest", "*");</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> litePullConsumer.setPullBatchSize(20);</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> litePullConsumer.start();</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> try {</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> while (running) {</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> List<MessageExt> messageExts = litePullConsumer.poll();</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> System.out.printf("%s%n", messageExts);</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> }</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> } finally {</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> litePullConsumer.shutdown();</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> }</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> }</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg viewBox="0 0 24 24" class="copyButtonIcon_y97N"><path fill="currentColor" d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg viewBox="0 0 24 24" class="copyButtonSuccessIcon_LjdS"><path fill="currentColor" d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>First of all, initialize <code>DefaultLitePullConsumer</code> and set <code>ConsumerGroupName</code>. Call the subscribe method afterward to subscribe to a topic and start it. Unlike the Push Consumer, <code>LitePullConsumer</code> pulls messages by the poll interface and returns the corresponding message list if it can pull the message, otherwise, it returns null. The maximum number of messages per pull can be set with <code>setPullBatchSize</code>, and the <code>LitePullConsumer</code> will automatically commits the offset by default. In the Subscribe mode, multiple <code>LitePullConsumer</code> under the same consumer group are load-balanced for consumption, consistent with the PushConsumer.</p><p>The following is an example of the Assign mode:</p><div class="language-java codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#393A34;--prism-background-color:#f6f8fa"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-java codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#393A34"><span class="token plain">public class LitePullConsumerAssign {</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> public static volatile boolean running = true;</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> public static void main(String[] args) throws Exception {</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> DefaultLitePullConsumer litePullConsumer = new DefaultLitePullConsumer("please_rename_unique_group_name");</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> litePullConsumer.setAutoCommit(false);</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> litePullConsumer.start();</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> Collection<MessageQueue> mqSet = litePullConsumer.fetchMessageQueues("TopicTest");</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> List<MessageQueue> list = new ArrayList<>(mqSet);</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> List<MessageQueue> assignList = new ArrayList<>();</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> for (int i = 0; i < list.size() / 2; i++) {</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> assignList.add(list.get(i));</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> }</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> litePullConsumer.assign(assignList);</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> litePullConsumer.seek(assignList.get(0), 10);</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> try {</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> while (running) {</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> List<MessageExt> messageExts = litePullConsumer.poll();</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> System.out.printf("%s %n", messageExts);</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> litePullConsumer.commitSync();</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> }</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> } finally {</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> litePullConsumer.shutdown();</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> }</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> }</span><br></span><span class="token-line" style="color:#393A34"><span class="token plain">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg viewBox="0 0 24 24" class="copyButtonIcon_y97N"><path fill="currentColor" d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg viewBox="0 0 24 24" class="copyButtonSuccessIcon_LjdS"><path fill="currentColor" d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>Assign mode still initializes <code>DefaultLitePullConsumer</code> at the beginning, here we use manual submission of offset, so set AutoCommit to false and then start the consumer. Unlike Subscribe mode, Assign mode does not have an automatic load balancing mechanism and requires the user to specify the queue to be pulled. Therefore, in the example, the queue under Topic is first fetched with fetchMessageQueues, and then half of the previous queue is fetched. The example also calls the seek method, which sets the offset in the first queue to be fetched from 10. Immediately after entering the loop keep calling the poll method to pull messages, and after pulling the messages call the commitSync method to manually submit the offset.</p></div><footer class="theme-doc-footer docusaurus-mt-lg"><div class="theme-doc-footer-edit-meta-row row"><div class="col"><a href="https://github.com/apache/rocketmq-site/tree/new-official-website/docs/03-consumer/03pull.md" target="_blank" rel="noreferrer noopener" class="theme-edit-this-page"><svg fill="currentColor" height="20" width="20" viewBox="0 0 40 40" class="iconEdit_Z9Sw" aria-hidden="true"><g><path d="m34.5 11.7l-3 3.1-6.3-6.3 3.1-3q0.5-0.5 1.2-0.5t1.1 0.5l3.9 3.9q0.5 0.4 0.5 1.1t-0.5 1.2z m-29.5 17.1l18.4-18.5 6.3 6.3-18.4 18.4h-6.3v-6.2z"></path></g></svg>Edit this page</a></div><div class="col lastUpdated_vwxv"></div></div></footer></article><nav class="pagination-nav docusaurus-mt-lg" aria-label="Docs pages navigation"><a class="pagination-nav__link pagination-nav__link--prev" 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