Simple Message Queue (formerly MNS):Use sample code to send a message to a topic

Prerequisites

• SMQ SDK for Java is installed. For more information, see Install SDK for Java.

• An endpoint and an access credential are configured. For more information, see Configure endpoints and access credentials.

Encoding methods for message bodies

Sample code

For more information about how to download the sample code, see PublishMessageDemo.java.

import com.aliyun.mns.client.CloudAccount;
import com.aliyun.mns.client.CloudTopic;
import com.aliyun.mns.client.MNSClient;
import com.aliyun.mns.common.utils.ServiceSettings;
import com.aliyun.mns.model.Base64TopicMessage;
import com.aliyun.mns.model.RawTopicMessage;
import com.aliyun.mns.model.TopicMessage;


/**
 * 1. Configure the AccessKey ID and AccessKey secret in the environment based on Alibaba Cloud specifications. 
 * 2. Configure the ${"user.home"}/.aliyun-mns.properties file based on the following content:
 *           mns.endpoint=http://xxxxxxx
 *           mns.msgBodyBase64Switch=true/false
 */
public class PublishMessageDemo {
    private static final Boolean IS_BASE64 = Boolean.valueOf(ServiceSettings.getMNSPropertyValue("msgBodyBase64Switch","false"));

    public static void main(String[] args) {
        String topicName = "TestTopic";
        String message = "hello world!";

        CloudAccount account = new CloudAccount(ServiceSettings.getMNSAccountEndpoint());
        //this client need only initialize once
        MNSClient client = account.getMNSClient();

        publishMsg(client, topicName, message);

        client.close();
    }

    private static void publishMsg(MNSClient client, String topicName, String message) {

        CloudTopic topic = client.getTopicRef(topicName);
        TopicMessage msg = IS_BASE64 ?  new Base64TopicMessage() : new RawTopicMessage();
        try {
            msg.setMessageBody(message);
            // Optional. Specify a filtering tag for the message.
            //msg.setMessageTag("filterTag");
            TopicMessage publishResultMsg = topic.publishMessage(msg);
            System.out.println("message publish.");
            System.out.println("reqId:"+publishResultMsg.getRequestId());
            System.out.println("msgId:"+publishResultMsg.getMessageId());
            System.out.println("md5:"+publishResultMsg.getMessageBodyMD5());
        } catch (Exception e) {
            e.printStackTrace();
            System.out.println("publishMsg error");
        }
    }
}