RabbitMQ系列-实现RPC异步调用
使用Spring AMQP实现RPC异步调用
示列
服务器端
应用启动类代码，
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;
import java.util.concurrent.TimeUnit;
@ComponentScan
public class Application {
public static void main(String[] args) throws Exception{
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(Application.class);
System.out.println("===server startup======");
TimeUnit.SECONDS.sleep(120);
context.close();
}
}
配置类：
监听了sms队列，这个队列将会是客户端请求消息发送到的队列，配置了适配器，适配器中去调用服务，适配器返回的值就是服务端返回给客户端的RPC调用的结果
import org.springframework.amqp.core.AcknowledgeMode;
import org.springframework.amqp.rabbit.connection.CachingConnectionFactory;
import org.springframework.amqp.rabbit.connection.ConnectionFactory;
import org.springframework.amqp.rabbit.core.RabbitAdmin;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer;
import org.springframework.amqp.rabbit.listener.adapter.MessageListenerAdapter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class MQConfig {
@Bean
public ConnectionFactory connectionFactory(){
CachingConnectionFactory factory = new CachingConnectionFactory();
factory.setUri("amqp://zhihao.miao:[email protected]:5672");
return factory;
}
@Bean
public RabbitAdmin rabbitAdmin(ConnectionFactory connectionFactory){
RabbitAdmin rabbitAdmin = new RabbitAdmin(connectionFactory);
return rabbitAdmin;
}
@Bean
public RabbitTemplate rabbitTemplate(ConnectionFactory connectionFactory){
RabbitTemplate rabbitTemplate = new RabbitTemplate(connectionFactory);
return rabbitTemplate;
}
@Bean
public SimpleMessageListenerContainer messageListenerContainer(ConnectionFactory connectionFactory){
SimpleMessageListenerContainer container = new SimpleMessageListenerContainer();
container.setConnectionFactory(connectionFactory);
container.setQueueNames("sms");
container.setAcknowledgeMode(AcknowledgeMode.NONE);
//使用适配器的方式
container.setMessageListener(new MessageListenerAdapter(new SendSMSHandler()));
return container;
}
}
处理器，处理器中调用具体的服务，我们此列子中处理器方法返回的值是boolean类型
import java.util.concurrent.TimeUnit;
public class SendSMSHandler {
public boolean handleMessage(byte[] body){
String _body = new String(body);
System.out.println(_body);
String[] sms = _body.split(":");
String phone = sms[0];
String content = sms[1];
boolean is = SendSMSTool.sendSMS(phone,content);
try {
TimeUnit.SECONDS.sleep(6);
} catch (InterruptedException e) {
e.printStackTrace();
}
return is;
}
}
服务接口
public class SendSMSTool {
public static boolean sendSMS(String phone,String content){
System.out.println("发送短信内容：【"+content+"】到手机号："+phone);
return phone.length() > 6;
}
}
服务端步骤
- 消息处理方法，一定要有返回值，这个返回值就是就是server回复客户端的结果。比如我们
SendSMSHandler.handleMessage方法返回的值。
客户端
应用启动类：
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessageProperties;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.amqp.rabbit.support.CorrelationData;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;
import java.util.UUID;
import java.util.concurrent.TimeUnit;
@ComponentScan
public class Application {
public static void main(String[] args) throws Exception{
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(Application.class);
RabbitTemplate rabbitTemplate = context.getBean(RabbitTemplate.class);
//设置超时时间，单位是ms
rabbitTemplate.setReplyTimeout(10000);
String phone = "15634344321";
String content ="周年庆，五折优惠";
MessageProperties messageProperties = new MessageProperties();
Message message = new Message((phone+":"+content).getBytes(),messageProperties);
//rabbitTemplate.send("","sms",message);
Message reply = rabbitTemplate.sendAndReceive("","sms",message,
new CorrelationData(UUID.randomUUID().toString()));
System.out.println(reply);
System.out.println("message,body:"+new String(reply.getBody()));
System.out.println("message,properties:"+reply.getMessageProperties());
TimeUnit.SECONDS.sleep(30);
context.close();
}
}
配置类代码：
import org.springframework.amqp.rabbit.connection.CachingConnectionFactory;
import org.springframework.amqp.rabbit.connection.ConnectionFactory;
import org.springframework.amqp.rabbit.core.RabbitAdmin;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class MQConfig {
@Bean
public ConnectionFactory connectionFactory(){
CachingConnectionFactory factory = new CachingConnectionFactory();
factory.setUri("amqp://zhihao.miao:[email protected]:5672");
return factory;
}
@Bean
public RabbitAdmin rabbitAdmin(ConnectionFactory connectionFactory){
RabbitAdmin rabbitAdmin = new RabbitAdmin(connectionFactory);
return rabbitAdmin;
}
@Bean
public RabbitTemplate rabbitTemplate(ConnectionFactory connectionFactory){
RabbitTemplate rabbitTemplate = new RabbitTemplate(connectionFactory);
return rabbitTemplate;
}
}
如果服务端睡眠6s，则客户端通过sendAndReceive方法接收到的Message对象为空，怎样设置呢？
客户端通过设置rabbitTemplate.setReplyTimeout(10000);就可以了。
客户端步骤
- 使用
sendAndReceive方法发送消息，该方法返回一个Message对象，该对象就是server返回的结果 sendAndReceive如果超过5s还没有收到结果，则返回null，这个超时时间可以通过rabbitTemplate.setReplyTimeout()来进行设置- server端返回的结果一定要注意，和
MessageConverter有关，默认的org.springframework.amqp.support.converter.SimpleMessageConverter会把基本的数据类型转换成Serializable对象，这样的话，client端接收的也是序列化的java对象，所以，需要合理设置MessageConverter。
示列代码中服务端返回给客户端的是Boolean类型,
启动服务端客户端代码：
服务器打印控制台打印：
15634344321:周年庆，五折优惠
发送短信内容：【周年庆，五折优惠】到手机号：15634344321
客户端控制台打印：
message,body:����sr��java.lang.Boolean� r�՜�����Z��valuexp�
message,properties:MessageProperties [headers={}, timestamp=null, messageId=null, userId=null, receivedUserId=null, appId=null, clusterId=null, type=null, correlationId=null, correlationIdString=null, replyTo=null, contentType=application/x-java-serialized-object, contentEncoding=null, contentLength=0, deliveryMode=null, receivedDeliveryMode=PERSISTENT, expiration=null, priority=0, redelivered=false, receivedExchange=, receivedRoutingKey=amq.rabbitmq.reply-to.g2dkAB5yYWJiaXRAaVpicDFqY3d4N3NmYjFud3pyZWh5NloAAFu0AAAABwI=.kHL9zxtdQmtcxl0mQF8zrg==, receivedDelay=null, deliveryTag=1, messageCount=null, consumerTag=null, consumerQueue=null]
我们发现客户端接收到的数据乱码，将服务端的处理器的返回值改写成String类型的，
import java.util.concurrent.TimeUnit;
public class SendSMSHandler {
public String handleMessage(byte[] body){
String _body = new String(body);
System.out.println(_body);
String[] sms = _body.split(":");
String phone = sms[0];
String content = sms[1];
boolean is = SendSMSTool.sendSMS(phone,content);
try {
TimeUnit.SECONDS.sleep(6);
} catch (InterruptedException e) {
e.printStackTrace();
}
return is ? "success":"false";
}
}
此时发现客户端接收的消息数据没有乱码，原因何在？我们总结一下就是服务器端处理器返回给客户端boolean类型，那么返回的消息数据就乱码，如果返回的是String类型，那么返回的消息数据就不会乱码。
之前我们学习了org.springframework.amqp.support.converter.MessageConverter接口，当客户端向服务端发送消息的时候会进行消息类型转换，调用了fromMessage方法，而当服务器返回给客户端的时候会将服务端的对象转换成Message对象，很明显调用的是toMessage方法。
我们知道org.springframework.amqp.support.converter.MessageConverter接口的默认实现是org.springframework.amqp.support.converter.SimpleMessageConverter，而toMessage方法的实现是在其继承的对象AbstractMessageConverter中，
我们看到其AbstractMessageConverter.toMessage方法的实现逻辑是：
@Override
public final Message toMessage(Object object, MessageProperties messageProperties)
throws MessageConversionException {
if (messageProperties == null) {
messageProperties = new MessageProperties();
}
//将对象转换成Message对象
Message message = createMessage(object, messageProperties);
messageProperties = message.getMessageProperties();
if (this.createMessageIds && messageProperties.getMessageId() == null) {
messageProperties.setMessageId(UUID.randomUUID().toString());
}
return message;
}
其createMessage方法就是将对象转换成Message对象，
/**
* Creates an AMQP Message from the provided Object.
*/
@Override
protected Message createMessage(Object object, MessageProperties messageProperties) throws MessageConversionException {
byte[] bytes = null;
if (object instanceof byte[]) {
bytes = (byte[]) object;
messageProperties.setContentType(MessageProperties.CONTENT_TYPE_BYTES);
}
else if (object instanceof String) {
try {
bytes = ((String) object).getBytes(this.defaultCharset);
}
catch (UnsupportedEncodingException e) {
throw new MessageConversionException(
"failed to convert to Message content", e);
}
messageProperties.setContentType(MessageProperties.CONTENT_TYPE_TEXT_PLAIN);
messageProperties.setContentEncoding(this.defaultCharset);
}
//因为boolean类型实现Serializable接口，所以会将其序列化
else if (object instanceof Serializable) {
try {
bytes = SerializationUtils.serialize(object);
}
catch (IllegalArgumentException e) {
throw new MessageConversionException(
"failed to convert to serialized Message content", e);
}
messageProperties.setContentType(MessageProperties.CONTENT_TYPE_SERIALIZED_OBJECT);
}
if (bytes != null) {
messageProperties.setContentLength(bytes.length);
}
return new Message(bytes, messageProperties);
}
我们在程序中将序列化对象直接转换成字符串所以乱码，而返回的是String类型的情形的时候先将字符串转换成相应的字节数组，然后返回new Message(bytes, messageProperties);就不会乱码。
继续探讨，当我们服务端返回的是一个对象的时候，客户端会返回空
返回的对象：
public class SendStatus {
private String phone;
private String result;
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
public String getResult() {
return result;
}
public void setResult(String result) {
this.result = result;
}
}
将该对象返回：
public class SendSMSHandler {
public SendStatus handleMessage(byte[] body){
String _body = new String(body);
System.out.println(_body);
String[] sms = _body.split(":");
String phone = sms[0];
String content = sms[1];
boolean is = SendSMSTool.sendSMS(phone,content);
SendStatus sendStatus = new SendStatus();
sendStatus.setPhone(phone);
sendStatus.setResult(is ? "SUCCESS":"FAILURE");
return sendStatus;
}
}
服务端控制台：
15634344321:周年庆，五折优惠
发送短信内容：【周年庆，五折优惠】到手机号：15634344321
客户端：
message,body:
message,properties:MessageProperties [headers={}, timestamp=null, messageId=null, userId=null, receivedUserId=null, appId=null, clusterId=null, type=null, correlationId=null, correlationIdString=null, replyTo=null, contentType=application/octet-stream, contentEncoding=null, contentLength=0, deliveryMode=null, receivedDeliveryMode=PERSISTENT, expiration=null, priority=0, redelivered=false, receivedExchange=, receivedRoutingKey=amq.rabbitmq.reply-to.g2dkAB5yYWJiaXRAaVpicDFqY3d4N3NmYjFud3pyZWh5NloAAFxBAAAABwI=.01fOGW/nvS2nz6gKza+cjg==, receivedDelay=null, deliveryTag=1, messageCount=null, consumerTag=null, consumerQueue=null]
原因何在，因为我们定义的SendStatus不走createMessage中的所有if分支，最后返回的是null，怎么解决呢，要么自己去定义一个org.springframework.amqp.support.converter.MessageConverter实现，要么换一个默认的org.springframework.amqp.support.converter.MessageConverter实现。
改造后的示列
使用AMQP自带的消息类型转换器Jackson2JsonMessageConverter
服务端
应用启动类，
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;
import java.util.concurrent.TimeUnit;
@ComponentScan
public class Application {
public static void main(String[] args) throws Exception{
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(Application.class);
System.out.println("===server startup======");
TimeUnit.SECONDS.sleep(120);
context.close();
}
}
配置类，添加自定义的消息转换器
import org.springframework.amqp.core.AcknowledgeMode;
import org.springframework.amqp.rabbit.connection.CachingConnectionFactory;
import org.springframework.amqp.rabbit.connection.ConnectionFactory;
import org.springframework.amqp.rabbit.core.RabbitAdmin;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer;
import org.springframework.amqp.rabbit.listener.adapter.MessageListenerAdapter;
import org.springframework.amqp.support.converter.Jackson2JsonMessageConverter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class MQConfig {
@Bean
public ConnectionFactory connectionFactory(){
CachingConnectionFactory factory = new CachingConnectionFactory();
factory.setUri("amqp://zhihao.miao:[email protected]:5672");
return factory;
}
@Bean
public RabbitAdmin rabbitAdmin(ConnectionFactory connectionFactory){
RabbitAdmin rabbitAdmin = new RabbitAdmin(connectionFactory);
return rabbitAdmin;
}
@Bean
public RabbitTemplate rabbitTemplate(ConnectionFactory connectionFactory){
RabbitTemplate rabbitTemplate = new RabbitTemplate(connectionFactory);
return rabbitTemplate;
}
@Bean
public SimpleMessageListenerContainer messageListenerContainer(ConnectionFactory connectionFactory){
SimpleMessageListenerContainer container = new SimpleMessageListenerContainer();
container.setConnectionFactory(connectionFactory);
container.setQueueNames("sms");
container.setAcknowledgeMode(AcknowledgeMode.NONE);
//使用适配器的方式
container.setMessageListener(new MessageListenerAdapter(new SendSMSHandler(),new Jackson2JsonMessageConverter()));
return container;
}
}
处理器handler，返回自定义的SendStatus类型
import java.util.concurrent.TimeUnit;
public class SendSMSHandler {
public SendStatus handleMessage(byte[] body){
String _body = new String(body);
System.out.println(_body);
String[] sms = _body.split(":");
String phone = sms[0];
String content = sms[1];
boolean is = SendSMSTool.sendSMS(phone,content);
SendStatus sendStatus = new SendStatus();
sendStatus.setPhone(phone);
sendStatus.setResult(is ? "SUCCESS":"FAILURE");
try {
TimeUnit.SECONDS.sleep(6);
} catch (InterruptedException e) {
e.printStackTrace();
}
return sendStatus;
}
}
接口服务，
public class SendSMSTool {
public static boolean sendSMS(String phone,String content){
System.out.println("发送短信内容：【"+content+"】到手机号："+phone);
return phone.length() > 6;
}
}
服务端返回的对象，
public class SendStatus {
private String phone;
private String result;
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
public String getResult() {
return result;
}
public void setResult(String result) {
this.result = result;
}
}
客户端
应用启动类，
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessageProperties;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.amqp.rabbit.support.CorrelationData;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;
import java.util.UUID;
import java.util.concurrent.TimeUnit;
@ComponentScan
public class Application {
public static void main(String[] args) throws Exception{
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(Application.class);
RabbitTemplate rabbitTemplate = context.getBean(RabbitTemplate.class);
//设置超时时间，单位是ms
rabbitTemplate.setReplyTimeout(10000);
String phone = "15634344321";
String content ="周年庆，五折优惠";
MessageProperties messageProperties = new MessageProperties();
Message message = new Message((phone+":"+content).getBytes(),messageProperties);
//rabbitTemplate.send("","sms",message);
Message reply = rabbitTemplate.sendAndReceive("","sms",message,
new CorrelationData(UUID.randomUUID().toString()));
System.out.println(reply);
System.out.println("message,body:"+new String(reply.getBody()));
System.out.println("message,properties:"+reply.getMessageProperties());
TimeUnit.SECONDS.sleep(30);
context.close();
}
}
配置类
import org.springframework.amqp.rabbit.connection.CachingConnectionFactory;
import org.springframework.amqp.rabbit.connection.ConnectionFactory;
import org.springframework.amqp.rabbit.core.RabbitAdmin;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class MQConfig {
@Bean
public ConnectionFactory connectionFactory(){
CachingConnectionFactory factory = new CachingConnectionFactory();
factory.setUri("amqp://zhihao.miao:[email protected]:5672");
return factory;
}
@Bean
public RabbitAdmin rabbitAdmin(ConnectionFactory connectionFactory){
RabbitAdmin rabbitAdmin = new RabbitAdmin(connectionFactory);
return rabbitAdmin;
}
@Bean
public RabbitTemplate rabbitTemplate(ConnectionFactory connectionFactory){
RabbitTemplate rabbitTemplate = new RabbitTemplate(connectionFactory);
return rabbitTemplate;
}
}
启动服务器客户端，客户端返回
message,body:{"phone":"15634344321","result":"SUCCESS"}
message,properties:MessageProperties [headers={__TypeId__=rpc.server.SendStatus}, timestamp=null, messageId=null, userId=null, receivedUserId=null, appId=null, clusterId=null, type=null, correlationId=null, correlationIdString=null, replyTo=null, contentType=application/json, contentEncoding=UTF-8, contentLength=0, deliveryMode=null, receivedDeliveryMode=PERSISTENT, expiration=null, priority=0, redelivered=false, receivedExchange=, receivedRoutingKey=amq.rabbitmq.reply-to
返回了SendStatus的JSON格式，因为使用了Jackson2JsonMessageConverter消息类型转换器。
转自:https://www.jianshu.com/p/24b88ccfb019