在第三方支付中,例如支付宝、或者微信,对于订单请求,第三方支付系统采用的是消息同步返回、异步通知+主动补偿查询的补偿机制。
由于互联网通信的不可靠性,例如双方网络、服务器、应用等因素的影响,不管是同步返回、异步通知、主动查询报文都可能出现超时无响应、报文丢失等情况,所以像支付业务,对结果的通知一般采用几种方案结合的补偿机制,不能完全依赖某一种机制。
例如一个支付结果的通知,一方面会在支付页面跳转时候返回支付结果(一般只用作前端展示使用,非最终状态),同时会采用后台异步通知机制(有前台、后台通知的,以后台异步通知结果为准),但由于前台跳转、后台结果通知都可能失效,因此还以定时补单+请求方主动查询接口作为辅助手段。
常见的补单操作,任务调度策略一般设定30秒、60秒、3分钟、6分钟、10分钟调度多次(以自己业务需要),如果调度接收到响应确认报文,补单成功,则中止对应订单的调度任务;如果超过补单上限次数,则停止补单,避免无谓的资源浪费。请求端随时可以发起请求报文查询对应订单的状态。
在日常开发中,对于网站前端来说,支付计费中心对于订单请求信息的处理也是通过消息同步返回、异步通知+主动补偿查询相结合的机制,其中对于订单的异步通知,目前的通知策略为3s、30s、60s、120s、180、300s的阶梯性通知。返回成功情况下就不继续通知了,本来打算使用将失败的消息写到数据库等待发送,然后每秒查询数据库获取消息通知前端。但觉得这样的处理方式太粗暴。存在以下缺点:
1 、每秒请求有点儿浪费资源; 2 、通知方式不稳定; 3 、无法承受大数据量等等
所以最终打算使用rabbitmq的消息延迟+死信队列来实现。消息模型如下:
producer发布消息,通过exchangeA的消息会被分发到QueueA,Consumer监听queueA,一旦有消息到来就被消费,这边的消费业务就是通知前端,如果通知失败,就创建一个延迟队列declareQueue,设置每个消息的ttl然后通过declare_exchange将消息分发到declare_queue,因为declare_queue没有consumer并且declare_queue中的消息设置了ttl,当ttl到期后,将通过DEX路由到queueA,被重新消费。
代码如下:DeclareQueue.java
- package org.delayQueue;
- import com.rabbitmq.client.BuiltinExchangeType;
- import com.rabbitmq.client.Channel;
- import com.rabbitmq.client.Connection;
- import com.rabbitmq.client.ConnectionFactory;
- public class DeclareQueue {
- public static String EXCHANGE_NAME = "notifyExchange";
- public static void init() {
- ConnectionFactory factory = new ConnectionFactory();
- factory.setHost("localhost");
- factory.setPort(5672);
- Connection connection = null;
- try {
- connection = factory.newConnection();
- Channel channel = connection.createChannel();
- channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.TOPIC);
- String routingKey = "AliPaynotify";
- String message = "http://localhost:8080/BossCenter/payGateway/notifyRecv.jsp?is_success=T?ify_id=4ab9bed148d043d0bf75460706f7774a?ify_time=2014-08-29+16%3A22%3A02?ify_type=trade_status_sync&out_trade_no=1421712120109862&total_fee=424.42&trade_no=14217121201098611&trade_status=TRADE_SUCCESS";
- channel.basicPublish(EXCHANGE_NAME, routingKey, null, message.getBytes());
- System.out.println(" [x] Sent :" + message);
- } catch (Exception e) {
- // TODO Auto-generated catch block
- e.printStackTrace();
- } finally {
- if (connection != null) {
- try {
- connection.close();
- } catch (Exception ignore) {
- }
- }
- }
- }
- public static void main(String args[]) {
- init();
- }
- }
DeclareConsumer.java
- package org.delayQueue;
- import java.io.BufferedReader;
- import java.io.IOException;
- import java.io.InputStreamReader;
- import java.util.ArrayList;
- import java.util.HashMap;
- import java.util.List;
- import java.util.Map;
- import java.util.Map.Entry;
- import org.apache.http.HttpResponse;
- import org.apache.http.client.ClientProtocolException;
- import org.apache.http.client.HttpClient;
- import org.apache.http.client.methods.HttpPost;
- import org.apache.http.impl.client.DefaultHttpClient;
- import com.rabbitmq.client.AMQP;
- import com.rabbitmq.client.Channel;
- import com.rabbitmq.client.Connection;
- import com.rabbitmq.client.ConnectionFactory;
- import com.rabbitmq.client.Consumer;
- import com.rabbitmq.client.DefaultConsumer;
- import com.rabbitmq.client.Envelope;
- public class DeclareConsumer {
- public static String EXCHANGE_NAME = "notifyExchange";
- public static String QU_declare_15S = "Qu_declare_15s";
- public static String EX_declare_15S = "EX_declare_15s";
- public static String ROUTINGKEY = "AliPaynotify";
- public static Connection connection = null;
- public static Channel channel = null;
- public static Channel DECLARE_15S_CHANNEL = null;
- public static String declare_queue = "init";
- public static String originalExpiration = "0";
- public static void init() throws Exception {
- ConnectionFactory factory = new ConnectionFactory();
- factory.setHost("localhost");
- factory.setPort(5672);
- connection = factory.newConnection();
- channel = connection.createChannel();
- DECLARE_15S_CHANNEL = connection.createChannel();
- }
- public static void consume() {
- try {
- channel.exchangeDeclare(EXCHANGE_NAME, "topic");
- final String queueName = channel.queueDeclare().getQueue();
- channel.queueBind(queueName, EXCHANGE_NAME, ROUTINGKEY);
- System.out.println(" [*] Waiting for messages. To exit press CTRL+C");
- final Consumer consumer = new DefaultConsumer(channel) {
- @Override
- public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
- String message = new String(body, "UTF-8");
- Map<String, Object> headers = properties.getHeaders();
- if (headers != null) {
- List<Map<String, Object>> xDeath = (List<Map<String, Object>>) headers.get("x-death");
- System.out.println("xDeath--- > " + xDeath);
- if (xDeath != null && !xDeath.isEmpty()) {
- Map<String, Object> entrys = xDeath.get(0);
- // for(Entry<String, Object>
- // entry:entrys.entrySet()){
- // System.out.println(entry.getKey()+":"+entry.getValue());
- // }
- originalExpiration = entrys.get("original-expiration").toString();
- }
- }
- System.out.println(" [x] Received ‘" + envelope.getRoutingKey() + "‘:‘" + message + "‘" + "time" + System.currentTimeMillis());
- HttpClient httpClient = new DefaultHttpClient();
- HttpPost post = new HttpPost(message);
- HttpResponse response = httpClient.execute(post);
- BufferedReader inreader = null;
- if (response.getStatusLine().getStatusCode() == 200) {
- inreader = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), "UTF-8"));
- StringBuffer responseBody = new StringBuffer();
- String line = null;
- while ((line = inreader.readLine()) != null) {
- responseBody.append(line);
- }
- if (!responseBody.equals("success")) {
- // putDeclre15s(message);
- if (originalExpiration.equals("0")) {
- putDeclreQueue(message, 3000, QU_declare_15S);
- }
- if (originalExpiration.equals("3000")) {
- putDeclreQueue(message, 30000, QU_declare_15S);
- }
- if (originalExpiration.equals("30000")) {
- putDeclreQueue(message, 60000, QU_declare_15S);
- }
- if (originalExpiration.equals("60000")) {
- putDeclreQueue(message, 120000, QU_declare_15S);
- }
- if (originalExpiration.equals("120000")) {
- putDeclreQueue(message, 180000, QU_declare_15S);
- }
- if (originalExpiration.equals("180000")) {
- putDeclreQueue(message, 300000, QU_declare_15S);
- }
- if (originalExpiration.equals("300000")) {
- // channel.basicConsume(QU_declare_300S,true, this);
- System.out.println("finish notify");
- }
- }
- } else {
- System.out.println(response.getStatusLine().getStatusCode());
- }
- }
- };
- channel.basicConsume(queueName, true, consumer);
- } catch (Exception e) {
- e.printStackTrace();
- } finally {
- }
- }
- static Map<String, Object> xdeathMap = new HashMap<String, Object>();
- static List<Map<String, Object>> xDeath = new ArrayList<Map<String, Object>>();
- static Map<String, Object> xdeathParam = new HashMap<String, Object>();
- public static void putDeclre15s(String message) throws IOException {
- channel.exchangeDeclare(EX_declare_15S, "topic");
- Map<String, Object> args = new HashMap<String, Object>();
- args.put("x-dead-letter-exchange", EXCHANGE_NAME);// 死信exchange
- AMQP.BasicProperties.Builder builder = new AMQP.BasicProperties.Builder();
- builder.expiration("3000").deliveryMode(2);// 设置消息TTL
- AMQP.BasicProperties properties = builder.build();
- channel.queueDeclare(QU_declare_15S, false, false, false, args);
- channel.queueBind(QU_declare_15S, EX_declare_15S, ROUTINGKEY);
- channel.basicPublish(EX_declare_15S, ROUTINGKEY, properties, message.getBytes());
- System.out.println("send message in QA_DEFERRED_15S" + message + "time" + System.currentTimeMillis());
- }
- public static void putDeclreQueue(String message, int mis, String queue) throws IOException {
- channel.exchangeDeclare(EX_declare_15S, "topic");
- Map<String, Object> args = new HashMap<String, Object>();
- args.put("x-dead-letter-exchange", EXCHANGE_NAME);// 死信exchange
- AMQP.BasicProperties.Builder builder = new AMQP.BasicProperties.Builder();
- builder.expiration(String.valueOf(mis)).deliveryMode(2);// 设置消息TTL
- AMQP.BasicProperties properties = builder.build();
- channel.queueDeclare(queue, false, false, false, args);
- channel.queueBind(queue, EX_declare_15S, ROUTINGKEY);
- channel.basicPublish(EX_declare_15S, ROUTINGKEY, properties, message.getBytes());
- System.out.println("send message in " + queue + message + "time============" + System.currentTimeMillis());
- }
- public static void main(String args[]) throws Exception {
- init();
- consume();
- }
- }
消息通过dlx转发的情况下,header头部会带有x-death的一个数组,里面包含消息的各项属性,比如说消息成为死信的原因reason,original-expiration这个字段表示消息在原来队列中的过期时间,根据这个值来确定下一次通知的延迟时间应该是多少秒。
运行结果如下:
原文地址:https://www.cnblogs.com/jpfss/p/9908853.html