【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 
项目地址：https://gitee.com/mdxl/blog.git
提前了解：Springboot事件监听配置，本博客以Springboot2.1.5版本集成配置。
1、安装RocketMQ
官网介绍，自己点击按照步骤走：http://rocketmq.apache.org/docs/quick-start/
不过在启动broker的时候，可以更改成如下命令，意思为RocketMQ支持自动创建topic，默认不支持。
nohup sh bin/mqbroker -n localhost:9876 autoCreateTopicEnable=true &
2、pom依赖
<dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency> <dependency> <groupId>org.apache.rocketmq</groupId> <artifactId>rocketmq-client</artifactId> <version>4.4.0</version> </dependency> <dependency> <groupId>org.apache.rocketmq</groupId> <artifactId>rocketmq-common</artifactId> <version>4.4.0</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-configuration-processor</artifactId> <optional>true</optional> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency>
3、application.properties
server.port=8081 # rocketMQ配置 myrocket.rocketmq.namesrvAddr=192.168.1.121:9876 myrocket.rocketmq.producer_groupName=user_producer_group myrocket.rocketmq.producer_transaction_groupName=order_transaction myrocket.rocketmq.producer_tranInstanceName=user_producer_transacition myrocket.rocketmq.producer_instanceName=user_producer_instance myrocket.rocketmq.consumer_instanceName=user_consumer_instance myrocket.rocketmq.consumer_groupName=user_consumer_group myrocket.rocketmq.consumer_batchMaxSize=1 myrocket.rocketmq.consumer_broadcasting=false myrocket.rocketmq.subscribe[0]=user-topic:white myrocket.rocketmq.enableHistoryConsumer=false myrocket.rocketmq.enableOrderConsumer=false
4、配置实体类
@Component
@Configuration
@PropertySource("classpath:application.properties")
@ConfigurationProperties(prefix = "myrocket.rocketmq")
@Data
public class RocketMQProperties {
// NameServer地址
private String namesrvAddr;
// 生产者group名
private String producer_groupName;
// 生产者事务group名
private String producer_transaction_groupName;
// 生产者事务实例名称
private String producer_tranInstanceName;
// 生产者实例名称
private String producer_instanceName;
// 消费者group名
private String consumer_groupName;
// 消费者实例名称
private String consumer_instanceName;
// 消费者一次最大消费多少数量消息
private int consumer_batchMaxSize;
// 广播消费
private boolean consumer_broadcasting;
// 启动的时候是否消费历史记录
private boolean enableHistoryConsumer;
// 启动顺序消费
private boolean enableOrderConsumer;
// 消费的topic：tag
private List<String> subscribe = new ArrayList<>();
}
5、事件监听类
public class MessageEvent extends ApplicationEvent {
private static final long serialVersionUID = -4468405250074063206L;
private DefaultMQPushConsumer consumer;
private List<MessageExt> msgs;
public MessageEvent(List<MessageExt> msgs, DefaultMQPushConsumer consumer) throws Exception {
super(msgs);
this.consumer = consumer;
this.setMsgs(msgs);
}
public DefaultMQPushConsumer getConsumer() {
return consumer;
}
public void setConsumer(DefaultMQPushConsumer consumer) {
this.consumer = consumer;
}
public List<MessageExt> getMsgs() {
return msgs;
}
public void setMsgs(List<MessageExt> msgs) {
this.msgs = msgs;
}
}
6、rocketMq配置类
@Configuration
@EnableConfigurationProperties(RocketMQProperties.class)
public class RocketMQConfiguration {
private static final Logger logger = LoggerFactory.getLogger(RocketMQConfiguration.class);
@Autowired
private RocketMQProperties rocketMQProperties;
//事件监听
@Autowired
private ApplicationEventPublisher publisher = null;
private static boolean isFirstSub = true;
private static long startTime = System.currentTimeMillis();
/**
* 初始化
*/
@PostConstruct
public void init() {
}
/**
* 创建普通消息发送者实例
*/
@Bean
public DefaultMQProducer defaultProducer() throws MQClientException {
DefaultMQProducer producer = new DefaultMQProducer(
rocketMQProperties.getProducer_groupName());
producer.setNamesrvAddr(rocketMQProperties.getNamesrvAddr());
producer.setInstanceName(rocketMQProperties.getProducer_instanceName());
producer.setVipChannelEnabled(false);
producer.setRetryTimesWhenSendAsyncFailed(10);
producer.start();
logger.info("rocketmq producer server is starting....");
return producer;
}
/**
* 创建支持消息事务发送的实例
*/
@Bean
public TransactionMQProducer transactionProducer() throws MQClientException {
TransactionMQProducer producer = new TransactionMQProducer(
rocketMQProperties.getProducer_transaction_groupName());
producer.setNamesrvAddr(rocketMQProperties.getNamesrvAddr());
producer.setInstanceName(rocketMQProperties
.getProducer_tranInstanceName());
producer.setRetryTimesWhenSendAsyncFailed(10);
// 事务回查最小并发数
producer.setCheckThreadPoolMinSize(2);
// 事务回查最大并发数
producer.setCheckThreadPoolMaxSize(2);
// 队列数
producer.setCheckRequestHoldMax(2000);
producer.start();
logger.info("rocketmq transaction producer server is starting....");
return producer;
}
/**
* 创建消息消费的实例
*/
@Bean
public DefaultMQPushConsumer pushConsumer() throws MQClientException {
DefaultMQPushConsumer consumer = new DefaultMQPushConsumer(
rocketMQProperties.getConsumer_groupName());
consumer.setNamesrvAddr(rocketMQProperties.getNamesrvAddr());
consumer.setInstanceName(rocketMQProperties.getConsumer_instanceName());
//判断是否是广播模式
if (rocketMQProperties.isConsumer_broadcasting()) {
consumer.setMessageModel(MessageModel.BROADCASTING);
}
//设置批量消费
consumer.setConsumeMessageBatchMaxSize(rocketMQProperties
.getConsumer_batchMaxSize() == 0 ? 1 : rocketMQProperties
.getConsumer_batchMaxSize());
//获取topic和tag
List<String> subscribeList = rocketMQProperties.getSubscribe();
for (String sunscribe : subscribeList) {
consumer.subscribe(sunscribe.split(":")[0], sunscribe.split(":")[1]);
}
// 顺序消费
if (rocketMQProperties.isEnableOrderConsumer()) {
consumer.registerMessageListener(new MessageListenerOrderly() {
@Override
public ConsumeOrderlyStatus consumeMessage(
List<MessageExt> msgs, ConsumeOrderlyContext context) {
try {
context.setAutoCommit(true);
msgs = filterMessage(msgs);
if (msgs.size() == 0)
return ConsumeOrderlyStatus.SUCCESS;
publisher.publishEvent(new MessageEvent(msgs, consumer));
} catch (Exception e) {
e.printStackTrace();
return ConsumeOrderlyStatus.SUSPEND_CURRENT_QUEUE_A_MOMENT;
}
return ConsumeOrderlyStatus.SUCCESS;
}
});
} else {
// 并发消费
consumer.registerMessageListener(new MessageListenerConcurrently() {
@Override
public ConsumeConcurrentlyStatus consumeMessage(
List<MessageExt> msgs,
ConsumeConcurrentlyContext context) {
try {
//过滤消息
msgs = filterMessage(msgs);
if (msgs.size() == 0)
return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
publisher.publishEvent(new MessageEvent(msgs, consumer));
} catch (Exception e) {
e.printStackTrace();
return ConsumeConcurrentlyStatus.RECONSUME_LATER;
}
return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
}
});
}
new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(5000);
try {
consumer.start();
} catch (Exception e) {
e.printStackTrace();
}
logger.info("rocketmq consumer server is starting....");
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}).start();
return consumer;
}
/**
* 消息过滤
*/
private List<MessageExt> filterMessage(List<MessageExt> msgs) {
if (isFirstSub && !rocketMQProperties.isEnableHistoryConsumer()) {
msgs = msgs.stream()
.filter(item -> startTime - item.getBornTimestamp() < 0)
.collect(Collectors.toList());
}
if (isFirstSub && msgs.size() > 0) {
isFirstSub = false;
}
return msgs;
}
}
7、实体类
@Data
public class User{
private String id;
private String userName;
}
8、service层
@Component
public class ConsumerService {
@EventListener(condition = "#event.msgs[0].topic=='user-topic' && #event.msgs[0].tags=='white'")
public void rocketmqMsgListener(MessageEvent event) {
try {
List<MessageExt> msgs = event.getMsgs();
for (MessageExt msg : msgs) {
System.err.println("消费消息:"+new String(msg.getBody()));
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
9、controller层
@RestController
public class ProducerController {
@Autowired
private DefaultMQProducer defaultProducer;
@Autowired
private TransactionMQProducer transactionProducer;
/**
* 发送普通消息
*/
@GetMapping("/sendMessage")
public void sendMsg() {
for(int i=0;i<10;i++){
User user = new User();
user.setId(String.valueOf(i));
user.setUserName("osc木九天"+i+"号");
String json = JSON.toJSONString(user);
Message msg = new Message("user-topic","white",json.getBytes());
try {
SendResult sendResult = defaultProducer.send(msg);
System.out.println("消息id:"+sendResult.getMsgId()+":"+","+"发送状态:"+sendResult.getSendStatus());
} catch (Exception e) {
e.printStackTrace();
}
}
}
/**
* 发送事务消息
* @return
*/
@GetMapping("/sendTransactionMess")
public String sendTransactionMsg() {
SendResult sendResult = null;
try {
// a,b,c三个值对应三个不同的状态
String ms = "c";
Message msg = new Message("user-topic","white",ms.getBytes());
// 发送事务消息
sendResult = transactionProducer.sendMessageInTransaction(msg, (Message msg1, Object arg) -> {
String value = "";
if (arg instanceof String) {
value = (String) arg;
}
if (value == "") {
throw new RuntimeException("发送消息不能为空...");
} else if (value =="a") {
return LocalTransactionState.ROLLBACK_MESSAGE;
} else if (value =="b") {
return LocalTransactionState.COMMIT_MESSAGE;
}
return LocalTransactionState.ROLLBACK_MESSAGE;
}, 4);
System.out.println(sendResult);
} catch (Exception e) {
e.printStackTrace();
}
return sendResult.toString();
}
/**
* 支持顺序发送消息
*/
@GetMapping("/sendMessOrder")
public void sendMsgOrder() {
for(int i=0;i<10;i++) {
User user = new User();
user.setId(String.valueOf(i));
user.setUserName("选手" + i);
String json = JSON.toJSONString(user);
Message msg = new Message("user-topic", "white", json.getBytes());
try{
SendResult sendResult = defaultProducer.send(msg, new MessageQueueSelector() {
@Override
public MessageQueue select(List<MessageQueue> mqs, Message msg, Object arg) {
int index = ((Integer) arg) % mqs.size();
return mqs.get(index);
}
},i);
System.out.println("消息id:"+sendResult.getMsgId()+":"+","+"发送状态:"+sendResult.getSendStatus());
} catch (Exception e){
e.printStackTrace();
}
}
}
}
10、测试
来源：oschina
链接：https://my.oschina.net/mdxlcj/blog/3153861