在第三方支付中,例如支付寶、或者微信,對於訂單請求,第三方支付系統採用的是消息同步返回、異步通知+主動補償查詢的補償機制。
例如一個支付結果的通知,一方面會在支付頁面跳轉時候返回支付結果(一般只用作前端展示使用,非最終狀態),同時會採用後臺異步通知機制(有前臺、後臺通知的,以後臺異步通知結果爲準),但由於前臺跳轉、後臺結果通知都可能失效,因此還以定時補單+請求方主動查詢接口作爲輔助手段。
常見的補單操作,任務調度策略一般設定30秒、60秒、3分鐘、6分鐘、10分鐘調度多次(以自己業務需要),如果調度接收到響應確認報文,補單成功,則中止對應訂單的調度任務;如果超過補單上限次數,則停止補單,避免無謂的資源浪費。請求端隨時可以發起請求報文查詢對應訂單的狀態。
producer發佈消息,通過exchangeA的消息會被分發到QueueA,Consumer監聽queueA,一旦有消息到來就被消費,這邊的消費業務就是通知前端,如果通知失敗,就創建一個延遲隊列declareQueue,設置每個消息的ttl然後通過declare_exchange將消息分發到declare_queue,因爲declare_queue沒有consumer並且declare_queue中的消息設置了ttl,當ttl到期後,將通過DEX路由到queueA,被重新消費。
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);// 設置消息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);// 設置消息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();
}
}
消息通過dlx轉發的情況下,header頭部會帶有x-death的一個數組,裏面包含消息的各項屬性,比如說消息成爲死信的原因reason,original-expiration這個字段表示消息在原來隊列中的過期時間,根據這個值來確定下一次通知的延遲時間應該是多少秒。