原文地址：RocketMQ樣例 - 一直在路上
在基本樣例中我們提供如下的功能場景：
maven:
<dependency>
<groupId>org.apache.rocketmq</groupId>
<artifactId>rocketmq-client</artifactId>
<version>4.3.0</version>
</dependency>
gradle
compile 'org.apache.rocketmq:rocketmq-client:4.3.0'
這種可靠性同步地發送方式使用的比較廣泛，比如：重要的訊息通知，簡訊通知。
public class SyncProducer {
public static void main(String[] args) throws Exception {
// 範例化訊息生產者Producer
DefaultMQProducer producer = new DefaultMQProducer("please_rename_unique_group_name");
// 設定NameServer的地址
producer.setNamesrvAddr("localhost:9876");
// 啓動Producer範例
producer.start();
for (int i = 0; i < 100; i++) {
// 建立訊息，並指定Topic，Tag和訊息體
Message msg = new Message("TopicTest" /* Topic */,
"TagA" /* Tag */,
("Hello RocketMQ " + i).getBytes(RemotingHelper.DEFAULT_CHARSET) /* Message body */
);
// 發送訊息到一個Broker
SendResult sendResult = producer.send(msg);
// 通過sendResult返回訊息是否成功送達
System.out.printf("%s%n", sendResult);
}
// 如果不再發送訊息，關閉Producer範例。
producer.shutdown();
}
}
非同步訊息通常用在對響應時間敏感的業務場景，即發送端不能容忍長時間地等待Broker的響應。
public class AsyncProducer {
public static void main(String[] args) throws Exception {
// 範例化訊息生產者Producer
DefaultMQProducer producer = new DefaultMQProducer("please_rename_unique_group_name");
// 設定NameServer的地址
producer.setNamesrvAddr("localhost:9876");
// 啓動Producer範例
producer.start();
producer.setRetryTimesWhenSendAsyncFailed(0);
int messageCount = 100;
// 根據訊息數量範例化倒計時計算器
final CountDownLatch2 countDownLatch = new CountDownLatch2(messageCount);
for (int i = 0; i < messageCount; i++) {
final int index = i;
// 建立訊息，並指定Topic，Tag和訊息體
Message msg = new Message("TopicTest",
"TagA",
"OrderID188",
"Hello world".getBytes(RemotingHelper.DEFAULT_CHARSET));
// SendCallback接收非同步返回結果的回撥
producer.send(msg, new SendCallback() {
@Override
public void onSuccess(SendResult sendResult) {
System.out.printf("%-10d OK %s %n", index,
sendResult.getMsgId());
}
@Override
public void onException(Throwable e) {
System.out.printf("%-10d Exception %s %n", index, e);
e.printStackTrace();
}
});
}
// 等待5s
countDownLatch.await(5, TimeUnit.SECONDS);
// 如果不再發送訊息，關閉Producer範例。
producer.shutdown();
}
}
這種方式主要用在不特別關心發送結果的場景，例如日誌發送。
public class OnewayProducer {
public static void main(String[] args) throws Exception{
// 範例化訊息生產者Producer
DefaultMQProducer producer = new DefaultMQProducer("please_rename_unique_group_name");
// 設定NameServer的地址
producer.setNamesrvAddr("localhost:9876");
// 啓動Producer範例
producer.start();
for (int i = 0; i < 100; i++) {
// 建立訊息，並指定Topic，Tag和訊息體
Message msg = new Message("TopicTest" /* Topic */,
"TagA" /* Tag */,
("Hello RocketMQ " + i).getBytes(RemotingHelper.DEFAULT_CHARSET) /* Message body */
);
// 發送單向訊息，沒有任何返回結果
producer.sendOneway(msg);
}
// 如果不再發送訊息，關閉Producer範例。
producer.shutdown();
}
}
public class Consumer {
public static void main(String[] args) throws InterruptedException, MQClientException {
// 範例化消費者
DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("please_rename_unique_group_name");
// 設定NameServer的地址
consumer.setNamesrvAddr("localhost:9876");
// 訂閱一個或者多個Topic，以及Tag來過濾需要消費的訊息
consumer.subscribe("TopicTest", "*");
// 註冊回撥實現類來處理從broker拉取回來的訊息
consumer.registerMessageListener(new MessageListenerConcurrently() {
@Override
public ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> msgs, ConsumeConcurrentlyContext context) {
System.out.printf("%s Receive New Messages: %s %n", Thread.currentThread().getName(), msgs);
// 標記該訊息已經被成功消費
return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
}
});
// 啓動消費者範例
consumer.start();
System.out.printf("Consumer Started.%n");
}
}
訊息有序指的是可以按照訊息的發送順序來消費(FIFO)。RocketMQ可以嚴格的保證訊息有序，可以分爲分割區有序或者全域性有序。
順序消費的原理解析，在預設的情況下訊息發送會採取Round Robin輪詢方式把訊息發送到不同的queue(分割區佇列)；而消費訊息的時候從多個queue上拉取訊息，這種情況發送和消費是不能保證順序。但是如果控制發送的順序訊息只依次發送到同一個queue中，消費的時候只從這個queue上依次拉取，則就保證了順序。當發送和消費參與的queue只有一個，則是全域性有序；如果多個queue參與，則爲分割區有序，即相對每個queue，訊息都是有序的。
下面 下麪用訂單進行分割區有序的範例。一個訂單的順序流程是：建立、付款、推播、完成。訂單號相同的訊息會被先後 先後發送到同一個佇列中，消費時，同一個OrderId獲取到的肯定是同一個佇列。
package org.apache.rocketmq.example.order2;
import org.apache.rocketmq.client.producer.DefaultMQProducer;
import org.apache.rocketmq.client.producer.MessageQueueSelector;
import org.apache.rocketmq.client.producer.SendResult;
import org.apache.rocketmq.common.message.Message;
import org.apache.rocketmq.common.message.MessageQueue;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
/**
* Producer，發送順序訊息
*/
public class Producer {
public static void main(String[] args) throws Exception {
DefaultMQProducer producer = new DefaultMQProducer("please_rename_unique_group_name");
producer.setNamesrvAddr("127.0.0.1:9876");
producer.start();
String[] tags = new String[]{"TagA", "TagC", "TagD"};
// 訂單列表
List<OrderStep> orderList = new Producer().buildOrders();
Date date = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String dateStr = sdf.format(date);
for (int i = 0; i < 10; i++) {
// 加個時間字首
String body = dateStr + " Hello RocketMQ " + orderList.get(i);
Message msg = new Message("TopicTest", tags[i % tags.length], "KEY" + i, body.getBytes());
SendResult sendResult = producer.send(msg, new MessageQueueSelector() {
@Override
public MessageQueue select(List<MessageQueue> mqs, Message msg, Object arg) {
Long id = (Long) arg; //根據訂單id選擇發送queue
long index = id % mqs.size();
return mqs.get((int) index);
}
}, orderList.get(i).getOrderId());//訂單id
System.out.println(String.format("SendResult status:%s, queueId:%d, body:%s",
sendResult.getSendStatus(),
sendResult.getMessageQueue().getQueueId(),
body));
}
producer.shutdown();
}
/**
* 訂單的步驟
*/
private static class OrderStep {
private long orderId;
private String desc;
public long getOrderId() {
return orderId;
}
public void setOrderId(long orderId) {
this.orderId = orderId;
}
public String getDesc() {
return desc;
}
public void setDesc(String desc) {
this.desc = desc;
}
@Override
public String toString() {
return "OrderStep{" +
"orderId=" + orderId +
", desc='" + desc + '\'' +
'}';
}
}
/**
* 生成模擬訂單數據
*/
private List<OrderStep> buildOrders() {
List<OrderStep> orderList = new ArrayList<OrderStep>();
OrderStep orderDemo = new OrderStep();
orderDemo.setOrderId(15103111039L);
orderDemo.setDesc("建立");
orderList.add(orderDemo);
orderDemo = new OrderStep();
orderDemo.setOrderId(15103111065L);
orderDemo.setDesc("建立");
orderList.add(orderDemo);
orderDemo = new OrderStep();
orderDemo.setOrderId(15103111039L);
orderDemo.setDesc("付款");
orderList.add(orderDemo);
orderDemo = new OrderStep();
orderDemo.setOrderId(15103117235L);
orderDemo.setDesc("建立");
orderList.add(orderDemo);
orderDemo = new OrderStep();
orderDemo.setOrderId(15103111065L);
orderDemo.setDesc("付款");
orderList.add(orderDemo);
orderDemo = new OrderStep();
orderDemo.setOrderId(15103117235L);
orderDemo.setDesc("付款");
orderList.add(orderDemo);
orderDemo = new OrderStep();
orderDemo.setOrderId(15103111065L);
orderDemo.setDesc("完成");
orderList.add(orderDemo);
orderDemo = new OrderStep();
orderDemo.setOrderId(15103111039L);
orderDemo.setDesc("推播");
orderList.add(orderDemo);
orderDemo = new OrderStep();
orderDemo.setOrderId(15103117235L);
orderDemo.setDesc("完成");
orderList.add(orderDemo);
orderDemo = new OrderStep();
orderDemo.setOrderId(15103111039L);
orderDemo.setDesc("完成");
orderList.add(orderDemo);
return orderList;
}
}
import org.apache.rocketmq.client.consumer.DefaultMQPushConsumer;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyContext;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyStatus;
import org.apache.rocketmq.client.consumer.listener.MessageListenerConcurrently;
import org.apache.rocketmq.common.message.MessageExt;
import java.util.List;
package org.apache.rocketmq.example.order2;
import org.apache.rocketmq.client.consumer.DefaultMQPushConsumer;
import org.apache.rocketmq.client.consumer.listener.ConsumeOrderlyContext;
import org.apache.rocketmq.client.consumer.listener.ConsumeOrderlyStatus;
import org.apache.rocketmq.client.consumer.listener.MessageListenerOrderly;
import org.apache.rocketmq.common.consumer.ConsumeFromWhere;
import org.apache.rocketmq.common.message.MessageExt;
import java.util.List;
import java.util.Random;
import java.util.concurrent.TimeUnit;
/**
* 順序訊息消費，帶事務方式（應用可控制Offset什麼時候提交）
*/
public class ConsumerInOrder {
public static void main(String[] args) throws Exception {
DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("please_rename_unique_group_name_3");
consumer.setNamesrvAddr("127.0.0.1:9876");
/**
* 設定Consumer第一次啓動是從佇列頭部開始消費還是佇列尾部開始消費<br>
* 如果非第一次啓動，那麼按照上次消費的位置繼續消費
*/
consumer.setConsumeFromWhere(ConsumeFromWhere.CONSUME_FROM_FIRST_OFFSET);
consumer.subscribe("TopicTest", "TagA || TagC || TagD");
consumer.registerMessageListener(new MessageListenerOrderly() {
Random random = new Random();
@Override
public ConsumeOrderlyStatus consumeMessage(List<MessageExt> msgs, ConsumeOrderlyContext context) {
context.setAutoCommit(true);
for (MessageExt msg : msgs) {
// 可以看到每個queue有唯一的consume執行緒來消費, 訂單對每個queue(分割區)有序
System.out.println("consumeThread=" + Thread.currentThread().getName() + "queueId=" + msg.getQueueId() + ", content:" + new String(msg.getBody()));
}
try {
//模擬業務邏輯處理中...
TimeUnit.SECONDS.sleep(random.nextInt(10));
} catch (Exception e) {
e.printStackTrace();
}
return ConsumeOrderlyStatus.SUCCESS;
}
});
consumer.start();
System.out.println("Consumer Started.");
}
}
import org.apache.rocketmq.client.consumer.DefaultMQPushConsumer;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyContext;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyStatus;
import org.apache.rocketmq.client.consumer.listener.MessageListenerConcurrently;
import org.apache.rocketmq.common.message.MessageExt;
import java.util.List;
public class ScheduledMessageConsumer {
public static void main(String[] args) throws Exception {
// 範例化消費者
DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("ExampleConsumer");
// 訂閱Topics
consumer.subscribe("TestTopic", "*");
// 註冊訊息監聽者
consumer.registerMessageListener(new MessageListenerConcurrently() {
@Override
public ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> messages, ConsumeConcurrentlyContext context) {
for (MessageExt message : messages) {
// Print approximate delay time period
System.out.println("Receive message[msgId=" + message.getMsgId() + "] " + (System.currentTimeMillis() - message.getStoreTimestamp()) + "ms later");
}
return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
}
});
// 啓動消費者
consumer.start();
}
}
import org.apache.rocketmq.client.producer.DefaultMQProducer;
import org.apache.rocketmq.common.message.Message;
public class ScheduledMessageProducer {
public static void main(String[] args) throws Exception {
// 範例化一個生產者來產生延時訊息
DefaultMQProducer producer = new DefaultMQProducer("ExampleProducerGroup");
// 啓動生產者
producer.start();
int totalMessagesToSend = 100;
for (int i = 0; i < totalMessagesToSend; i++) {
Message message = new Message("TestTopic", ("Hello scheduled message " + i).getBytes());
// 設定延時等級3,這個訊息將在10s之後發送(現在只支援固定的幾個時間,詳看delayTimeLevel)
message.setDelayTimeLevel(3);
// 發送訊息
producer.send(message);
}
// 關閉生產者
producer.shutdown();
}
}
您將會看到訊息的消費比儲存時間晚10秒。
比如電商裡，提交了一個訂單就可以發送一個延時訊息，1h後去檢查這個訂單的狀態，如果還是未付款就取消訂單釋放庫存。
// org/apache/rocketmq/store/config/MessageStoreConfig.java
private String messageDelayLevel = "1s 5s 10s 30s 1m 2m 3m 4m 5m 6m 7m 8m 9m 10m 20m 30m 1h 2h";
現在RocketMq並不支援任意時間的延時，需要設定幾個固定的延時等級，從1s到2h分別對應着等級1到18
訊息消費失敗會進入延時訊息佇列，訊息發送時間與設定的延時等級和重試次數有關，詳見程式碼SendMessageProcessor.java
批次發送訊息能顯著提高傳遞小訊息的效能。限制是這些批次訊息應該有相同的topic，相同的waitStoreMsgOK，而且不能是延時訊息。此外，這一批訊息的總大小不應超過4MB。
如果您每次只發送不超過4MB的訊息，則很容易使用批次處理，樣例如下：
String topic = "BatchTest";
List<Message> messages = new ArrayList<>();
messages.add(new Message(topic, "TagA", "OrderID001", "Hello world 0".getBytes()));
messages.add(new Message(topic, "TagA", "OrderID002", "Hello world 1".getBytes()));
messages.add(new Message(topic, "TagA", "OrderID003", "Hello world 2".getBytes()));
try {
producer.send(messages);
} catch (Exception e) {
e.printStackTrace();
//處理error
}
複雜度只有當你發送大批次時纔會增長，你可能不確定它是否超過了大小限制（4MB）。這時候你最好把你的訊息列表分割一下：
public class ListSplitter implements Iterator<List<Message>> {
private final int SIZE_LIMIT = 1024 * 1024 * 4;
private final List<Message> messages;
private int currIndex;
public ListSplitter(List<Message> messages) {
this.messages = messages;
}
@Override public boolean hasNext() {
return currIndex < messages.size();
}
@Override public List<Message> next() {
int startIndex = getStartIndex();
int nextIndex = startIndex;
int totalSize = 0;
for (; nextIndex < messages.size(); nextIndex++) {
Message message = messages.get(nextIndex);
int tmpSize = calcMessageSize(message);
if (tmpSize + totalSize > SIZE_LIMIT) {
break;
} else {
totalSize += tmpSize;
}
}
List<Message> subList = messages.subList(startIndex, nextIndex);
currIndex = nextIndex;
return subList;
}
private int getStartIndex() {
Message currMessage = messages.get(currIndex);
int tmpSize = calcMessageSize(currMessage);
while(tmpSize > SIZE_LIMIT) {
currIndex += 1;
Message message = messages.get(curIndex);
tmpSize = calcMessageSize(message);
}
return currIndex;
}
private int calcMessageSize(Message message) {
int tmpSize = message.getTopic().length() + message.getBody().length();
Map<String, String> properties = message.getProperties();
for (Map.Entry<String, String> entry : properties.entrySet()) {
tmpSize += entry.getKey().length() + entry.getValue().length();
}
tmpSize = tmpSize + 20; // 增加⽇日誌的開銷20位元組
return tmpSize;
}
}
//把大的訊息分裂成若幹個小的訊息
ListSplitter splitter = new ListSplitter(messages);
while (splitter.hasNext()) {
try {
List<Message> listItem = splitter.next();
producer.send(listItem);
} catch (Exception e) {
e.printStackTrace();
//處理error
}
}
在大多數情況下，TAG是一個簡單而有用的設計，其可以來選擇您想要的訊息。例如：
DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("CID_EXAMPLE");
consumer.subscribe("TOPIC", "TAGA || TAGB || TAGC");
消費者將接收包含TAGA或TAGB或TAGC的訊息。但是限制是一個訊息只能有一個標籤，這對於複雜的場景可能不起作用。在這種情況下，可以使用SQL表達式篩選訊息。SQL特性可以通過發送訊息時的屬性來進行計算。在RocketMQ定義的語法下，可以實現一些簡單的邏輯。下面 下麪是一個例子：
------------
| message |
|----------| a > 5 AND b = 'abc'
| a = 10 | --------------------> Gotten
| b = 'abc'|
| c = true |
------------
------------
| message |
|----------| a > 5 AND b = 'abc'
| a = 1 | --------------------> Missed
| b = 'abc'|
| c = true |
------------
RocketMQ只定義了一些基本語法來支援這個特性。你也可以很容易地擴充套件它。
常數支援型別爲：
只有使用push模式的消費者才能 纔能用使用SQL92標準的sql語句，介面如下：
public void subscribe(finalString topic, final MessageSelector messageSelector)
發送訊息時，你能通過putUserProperty來設定訊息的屬性
DefaultMQProducer producer = new DefaultMQProducer("please_rename_unique_group_name");
producer.start();
Message msg = new Message("TopicTest",
tag,
("Hello RocketMQ " + i).getBytes(RemotingHelper.DEFAULT_CHARSET)
);
// 設定一些屬性
msg.putUserProperty("a", String.valueOf(i));
SendResult sendResult = producer.send(msg);
producer.shutdown();
用MessageSelector.bySql來使用sql篩選訊息
DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("please_rename_unique_group_name_4");
// 只有訂閱的訊息有這個屬性a, a >=0 and a <= 3
consumer.subscribe("TopicTest", MessageSelector.bySql("a between 0 and 3");
consumer.registerMessageListener(new MessageListenerConcurrently() {
@Override
public ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> msgs, ConsumeConcurrentlyContext context) {
return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
}
});
consumer.start();
事務訊息共有三種狀態，提交狀態、回滾狀態、中間狀態：
使用 TransactionMQProducer類建立生產者，並指定唯一的 ProducerGroup，就可以設定自定義執行緒池來處理這些檢查請求。執行本地事務後、需要根據執行結果對訊息佇列進行回覆 回復。回傳的事務狀態在請參考前一節。
import org.apache.rocketmq.client.consumer.DefaultMQPushConsumer;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyContext;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyStatus;
import org.apache.rocketmq.client.consumer.listener.MessageListenerConcurrently;
import org.apache.rocketmq.common.message.MessageExt;
import java.util.List;
public class TransactionProducer {
public static void main(String[] args) throws MQClientException, InterruptedException {
TransactionListener transactionListener = new TransactionListenerImpl();
TransactionMQProducer producer = new TransactionMQProducer("please_rename_unique_group_name");
ExecutorService executorService = new ThreadPoolExecutor(2, 5, 100, TimeUnit.SECONDS, new ArrayBlockingQueue<Runnable>(2000), new ThreadFactory() {
@Override
public Thread newThread(Runnable r) {
Thread thread = new Thread(r);
thread.setName("client-transaction-msg-check-thread");
return thread;
}
});
producer.setExecutorService(executorService);
producer.setTransactionListener(transactionListener);
producer.start();
String[] tags = new String[] {"TagA", "TagB", "TagC", "TagD", "TagE"};
for (int i = 0; i < 10; i++) {
try {
Message msg =
new Message("TopicTest1234", tags[i % tags.length], "KEY" + i,
("Hello RocketMQ " + i).getBytes(RemotingHelper.DEFAULT_CHARSET));
SendResult sendResult = producer.sendMessageInTransaction(msg, null);
System.out.printf("%s%n", sendResult);
Thread.sleep(10);
} catch (MQClientException | UnsupportedEncodingException e) {
e.printStackTrace();
}
}
for (int i = 0; i < 100000; i++) {
Thread.sleep(1000);
}
producer.shutdown();
}
}
當發送半訊息成功時，我們使用 executeLocalTransaction 方法來執行本地事務。它返回前一節中提到的三個事務狀態之一。checkLocalTransaction 方法用於檢查本地事務狀態，並回應訊息佇列的檢查請求。它也是返回前一節中提到的三個事務狀態之一。
public class TransactionListenerImpl implements TransactionListener {
private AtomicInteger transactionIndex = new AtomicInteger(0);
private ConcurrentHashMap<String, Integer> localTrans = new ConcurrentHashMap<>();
@Override
public LocalTransactionState executeLocalTransaction(Message msg, Object arg) {
int value = transactionIndex.getAndIncrement();
int status = value % 3;
localTrans.put(msg.getTransactionId(), status);
return LocalTransactionState.UNKNOW;
}
@Override
public LocalTransactionState checkLocalTransaction(MessageExt msg) {
Integer status = localTrans.get(msg.getTransactionId());
if (null != status) {
switch (status) {
case 0:
return LocalTransactionState.UNKNOW;
case 1:
return LocalTransactionState.COMMIT_MESSAGE;
case 2:
return LocalTransactionState.ROLLBACK_MESSAGE;
}
}
return LocalTransactionState.COMMIT_MESSAGE;
}
}
transactionCheckMax參數來修改此限制。如果已經檢查某條訊息超過 N 次的話（ N = transactionCheckMax ） 則 Broker 將丟棄此訊息，並在預設情況下同時列印錯誤日誌。使用者可以通過重寫 AbstractTransactionalMessageCheckListener 類來修改這個行爲。transactionTimeout 參數。RocketMQ日誌提供log4j、log4j2和logback日誌框架作爲業務應用，下面 下麪是設定樣例
按下面 下麪樣例使用log4j屬性設定
log4j.appender.mq=org.apache.rocketmq.logappender.log4j.RocketmqLog4jAppender
log4j.appender.mq.Tag=yourTag
log4j.appender.mq.Topic=yourLogTopic
log4j.appender.mq.ProducerGroup=yourLogGroup
log4j.appender.mq.NameServerAddress=yourRocketmqNameserverAddress
log4j.appender.mq.layout=org.apache.log4j.PatternLayout
log4j.appender.mq.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-4r [%t] (%F:%L) %-5p - %m%n
按下面 下麪樣例使用log4j xml設定來使用非同步新增日誌
<appender name="mqAppender1"class="org.apache.rocketmq.logappender.log4j.RocketmqLog4jAppender">
<param name="Tag" value="yourTag" />
<param name="Topic" value="yourLogTopic" />
<param name="ProducerGroup" value="yourLogGroup" />
<param name="NameServerAddress" value="yourRocketmqNameserverAddress"/>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d{yyyy-MM-dd HH:mm:ss}-%p %t %c - %m%n" />
</layout>
</appender>
<appender name="mqAsyncAppender1"class="org.apache.log4j.AsyncAppender">
<param name="BufferSize" value="1024" />
<param name="Blocking" value="false" />
<appender-ref ref="mqAppender1"/>
</appender>
用log4j2時，設定如下，如果想要非阻塞，只需要使用非同步新增參照即可
<RocketMQ name="rocketmqAppender" producerGroup="yourLogGroup" nameServerAddress="yourRocketmqNameserverAddress"
topic="yourLogTopic" tag="yourTag">
<PatternLayout pattern="%d [%p] hahahah %c %m%n"/>
</RocketMQ>
<appender name="mqAppender1"class="org.apache.rocketmq.logappender.logback.RocketmqLogbackAppender">
<tag>yourTag</tag>
<topic>yourLogTopic</topic>
<producerGroup>yourLogGroup</producerGroup>
<nameServerAddress>yourRocketmqNameserverAddress</nameServerAddress>
<layout>
<pattern>%date %p %t - %m%n</pattern>
</layout>
</appender>
<appender name="mqAsyncAppender1"class="ch.qos.logback.classic.AsyncAppender">
<queueSize>1024</queueSize>
<discardingThreshold>80</discardingThreshold>
<maxFlushTime>2000</maxFlushTime>
<neverBlock>true</neverBlock>
<appender-ref ref="mqAppender1"/>
</appender>
OpenMessaging旨在建立訊息和流處理規範，以爲金融、電子商務、物聯網和大數據領域提供通用框架及工業級指導方案。在分佈式異構環境中，設計原則是面向雲、簡單、靈活和獨立於語言。符合這些規範將幫助企業方便的開發跨平臺和操作系統的異構訊息傳遞應用程式。提供了openmessaging-api 0.3.0-alpha的部分實現，下面 下麪的範例演示如何基於OpenMessaging存取RocketMQ。
下面 下麪的範例演示如何在同步、非同步或單向傳輸中向RocketMQ代理髮送訊息。
import io.openmessaging.Future;
import io.openmessaging.FutureListener;
import io.openmessaging.Message;
import io.openmessaging.MessagingAccessPoint;
import io.openmessaging.OMS;
import io.openmessaging.producer.Producer;
import io.openmessaging.producer.SendResult;
import java.nio.charset.Charset;
import java.util.concurrent.CountDownLatch;
public class SimpleProducer {
public static void main(String[] args) {
final MessagingAccessPoint messagingAccessPoint =
OMS.getMessagingAccessPoint("oms:rocketmq://localhost:9876/default:default");
final Producer producer = messagingAccessPoint.createProducer();
messagingAccessPoint.startup();
System.out.printf("MessagingAccessPoint startup OK%n");
producer.startup();
System.out.printf("Producer startup OK%n");
{
Message message = producer.createBytesMessage("OMS_HELLO_TOPIC", "OMS_HELLO_BODY".getBytes(Charset.forName("UTF-8")));
SendResult sendResult = producer.send(message);
//final Void aVoid = result.get(3000L);
System.out.printf("Send async message OK, msgId: %s%n", sendResult.messageId());
}
final CountDownLatch countDownLatch = new CountDownLatch(1);
{
final Future<SendResult> result = producer.sendAsync(producer.createBytesMessage("OMS_HELLO_TOPIC", "OMS_HELLO_BODY".getBytes(Charset.forName("UTF-8"))));
result.addListener(new FutureListener<SendResult>() {
@Override
public void operationComplete(Future<SendResult> future) {
if (future.getThrowable() != null) {
System.out.printf("Send async message Failed, error: %s%n", future.getThrowable().getMessage());
} else {
System.out.printf("Send async message OK, msgId: %s%n", future.get().messageId());
}
countDownLatch.countDown();
}
});
}
{
producer.sendOneway(producer.createBytesMessage("OMS_HELLO_TOPIC", "OMS_HELLO_BODY".getBytes(Charset.forName("UTF-8"))));
System.out.printf("Send oneway message OK%n");
}
try {
countDownLatch.await();
Thread.sleep(500); // 等一些時間來發送訊息
} catch (InterruptedException ignore) {
}
producer.shutdown();
}
}
用OMS PullConsumer 來從指定的佇列中拉取訊息
import io.openmessaging.Message;
import io.openmessaging.MessagingAccessPoint;
import io.openmessaging.OMS;
import io.openmessaging.OMSBuiltinKeys;
import io.openmessaging.consumer.PullConsumer;
import io.openmessaging.producer.Producer;
import io.openmessaging.producer.SendResult;
public class SimplePullConsumer {
public static void main(String[] args) {
final MessagingAccessPoint messagingAccessPoint =
OMS.getMessagingAccessPoint("oms:rocketmq://localhost:9876/default:default");
messagingAccessPoint.startup();
final Producer producer = messagingAccessPoint.createProducer();
final PullConsumer consumer = messagingAccessPoint.createPullConsumer(
OMS.newKeyValue().put(OMSBuiltinKeys.CONSUMER_ID, "OMS_CONSUMER"));
messagingAccessPoint.startup();
System.out.printf("MessagingAccessPoint startup OK%n");
final String queueName = "TopicTest";
producer.startup();
Message msg = producer.createBytesMessage(queueName, "Hello Open Messaging".getBytes());
SendResult sendResult = producer.send(msg);
System.out.printf("Send Message OK. MsgId: %s%n", sendResult.messageId());
producer.shutdown();
consumer.attachQueue(queueName);
consumer.startup();
System.out.printf("Consumer startup OK%n");
// 執行直到發現一個訊息被髮送了
boolean stop = false;
while (!stop) {
Message message = consumer.receive();
if (message != null) {
String msgId = message.sysHeaders().getString(Message.BuiltinKeys.MESSAGE_ID);
System.out.printf("Received one message: %s%n", msgId);
consumer.ack(msgId);
if (!stop) {
stop = msgId.equalsIgnoreCase(sendResult.messageId());
}
} else {
System.out.printf("Return without any message%n");
}
}
consumer.shutdown();
messagingAccessPoint.shutdown();
}
}
以下示範如何將 OMS PushConsumer 新增到指定的佇列，並通過 MessageListener 消費這些訊息。
import io.openmessaging.Message;
import io.openmessaging.MessagingAccessPoint;
import io.openmessaging.OMS;
import io.openmessaging.OMSBuiltinKeys;
import io.openmessaging.consumer.MessageListener;
import io.openmessaging.consumer.PushConsumer;
public class SimplePushConsumer {
public static void main(String[] args) {
final MessagingAccessPoint messagingAccessPoint = OMS
.getMessagingAccessPoint("oms:rocketmq://localhost:9876/default:default");
final PushConsumer consumer = messagingAccessPoint.
createPushConsumer(OMS.newKeyValue().put(OMSBuiltinKeys.CONSUMER_ID, "OMS_CONSUMER"));
messagingAccessPoint.startup();
System.out.printf("MessagingAccessPoint startup OK%n");
Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() {
@Override
public void run() {
consumer.shutdown();
messagingAccessPoint.shutdown();
}
}));
consumer.attachQueue("OMS_HELLO_TOPIC", new MessageListener() {
@Override
public void onReceived(Message message, Context context) {
System.out.printf("Received one message: %s%n", message.sysHeaders().getString(Message.BuiltinKeys.MESSAGE_ID));
context.ack();
}
});
consumer.startup();
System.out.printf("Consumer startup OK%n");
}
}