RocketMQ是我们常用的消息中间件，在运行单元测试时，我们可能不需要真正发送消息（除非是为了测试发送消息），也不想因为连结不上RocketMQ的Broker,NameServer而影响单元测试运行。
那我们该如何Mock RocketMQ消息生产者呢？
请看例子：
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//RocketMQ消息生产者 Mock public class RocetMQProducerMockingTest { // 把RocketMQ的生产者mock @BeforeClass public static void mockRocketMQ() { new RocketMQProducerMockUp(); } @Test public void testSendRocketMQMessage() throws Exception { DefaultMQProducer producer = new DefaultMQProducer("test_producer"); producer.setNamesrvAddr("192.168.0.2:9876;192.168.0.3:9876"); producer.start(); for (int i = 0; i < 20; i++) { Message msg = new Message("testtopic", "TagA", ("Hello " + i).getBytes()); // 因为mq生产者已经mock,所以消息并不会真正的发送，即使nameServer连不上，也不影响单元测试的运行 SendResult result = producer.send(msg); Assert.isTrue(result.getSendStatus() == SendStatus.SEND_OK); Assert.isTrue(result.getMsgId() != null); } producer.shutdown(); }} |
最关键的类是RocketMQProducerMockUp，这个类改变了生产者默认实现。代码如下：
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//MQ消息发送者 的MockUp(伪类） public class RocketMQProducerMockUp extends MockUp<DefaultMQProducer> { @Mock void init() throws MQClientException { // 构造函数也什么都不做 } @Mock void start() throws MQClientException { // 启动，什么都不做 } @Mock void shutdown() { // 关闭，也什么都不做 } @Mock List<MessageQueue> fetchPublishMessageQueues(final String topic) throws MQClientException { // 欺骗调用方，返回不存在的消息队列，因为消息并不会真正发送嘛 List<MessageQueue> queues = new ArrayList<MessageQueue>(); MessageQueue q = new MessageQueue(); q.setBrokerName("testbrokername"); q.setQueueId(1); q.setTopic("testtopic"); queues.add(q); return queues; } // 下面是对各个send方法的mock,都返回消息成功结果 @Mock SendResult send(final Message msg) throws MQClientException, RemotingException, MQBrokerException, InterruptedException { return newSuccessSendResult(); } @Mock SendResult send(final Message msg, final long timeout) throws MQClientException, RemotingException, MQBrokerException, InterruptedException { return newSuccessSendResult(); } @Mock void send(final Message msg, final SendCallback sendCallback) throws MQClientException, RemotingException, InterruptedException { sendCallback.onSuccess(this.newSuccessSendResult()); } @Mock void send(final Message msg, final SendCallback sendCallback, final long timeout) throws MQClientException, RemotingException, InterruptedException { sendCallback.onSuccess(this.newSuccessSendResult()); } @Mock void sendOneway(final Message msg) throws MQClientException, RemotingException, InterruptedException { } @Mock SendResult send(final Message msg, final MessageQueue mq) throws MQClientException, RemotingException, MQBrokerException, InterruptedException { return newSuccessSendResult(); } @Mock SendResult send(final Message msg, final MessageQueue mq, final long timeout) throws MQClientException, RemotingException, MQBrokerException, InterruptedException { return newSuccessSendResult(); } @Mock void send(final Message msg, final MessageQueue mq, final SendCallback sendCallback) throws MQClientException, RemotingException, InterruptedException { sendCallback.onSuccess(this.newSuccessSendResult()); } @Mock void send(final Message msg, final MessageQueue mq, final SendCallback sendCallback, long timeout) throws MQClientException, RemotingException, InterruptedException { sendCallback.onSuccess(this.newSuccessSendResult()); } @Mock void sendOneway(final Message msg, final MessageQueue mq) throws MQClientException, RemotingException, InterruptedException { } @Mock SendResult send(final Message msg, final MessageQueueSelector selector, final Object arg) throws MQClientException, RemotingException, MQBrokerException, InterruptedException { return newSuccessSendResult(); } @Mock SendResult send(final Message msg, final MessageQueueSelector selector, final Object arg, final long timeout) throws MQClientException, RemotingException, MQBrokerException, InterruptedException { return newSuccessSendResult(); } @Mock void send(final Message msg, final MessageQueueSelector selector, final Object arg, final SendCallback sendCallback) throws MQClientException, RemotingException, InterruptedException { sendCallback.onSuccess(this.newSuccessSendResult()); } @Mock void send(final Message msg, final MessageQueueSelector selector, final Object arg, final SendCallback sendCallback, final long timeout) throws MQClientException, RemotingException, InterruptedException { sendCallback.onSuccess(this.newSuccessSendResult()); } @Mock void sendOneway(final Message msg, final MessageQueueSelector selector, final Object arg) throws MQClientException, RemotingException, InterruptedException { } @Mock TransactionSendResult sendMessageInTransaction(final Message msg, final LocalTransactionExecuter tranExecuter, final Object arg) throws MQClientException { return newTransactionSendResult(); } private TransactionSendResult newTransactionSendResult() { TransactionSendResult success = new TransactionSendResult(); success.setSendStatus(SendStatus.SEND_OK); success.setMsgId(UUID.randomUUID().toString()); MessageQueue q = new MessageQueue(); q.setBrokerName("testbrokername"); q.setQueueId(1); q.setTopic("testtopic"); success.setMessageQueue(q); success.setLocalTransactionState(LocalTransactionState.COMMIT_MESSAGE); return success; } private SendResult newSuccessSendResult() { SendResult success = new SendResult(); success.setSendStatus(SendStatus.SEND_OK); success.setMsgId(UUID.randomUUID().toString()); MessageQueue q = new MessageQueue(); q.setBrokerName("testbrokername"); q.setQueueId(1); q.setTopic("testtopic"); success.setMessageQueue(q); return success; }}
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来源：https://www.cnblogs.com/funkboy/p/12012559.html