java.md

Java SDK

Package: com.robustmq.mq9
Requires: Java 17+, jnats, jackson-databind

Install

<dependency>
  <groupId>com.robustmq</groupId>
  <artifactId>robustmq</artifactId>
  <version>1.0.1</version>
</dependency>

Quick start

import com.robustmq.mq9.*;
import java.util.List;

MQ9Client client = new MQ9Client("nats://demo.robustmq.com:4222");
client.connect();

// Create mailbox
Mailbox mailbox = client.create(3600).get();

// Send
client.send(mailbox.getMailId(), "hello".getBytes(), Priority.NORMAL).get();

// Subscribe
var dispatcher = client.subscribe(mailbox.getMailId(), msg ->
    System.out.println(new String(msg.getPayload())),
    null, "").get();

// List metadata (no payload)
List<MessageMeta> metas = client.list(mailbox.getMailId()).get();
// metas.get(i).getMsgId(), .getPriority(), .getTs()

// Delete
client.delete(mailbox.getMailId(), metas.get(0).getMsgId()).get();

dispatcher.unsubscribe(null);
client.close();

API

MQ9Client(String server)

void connect() throws MQ9Error
void close()                          // AutoCloseable

CompletableFuture<Mailbox> create(int ttl)
CompletableFuture<Mailbox> createPublic(int ttl, String name, String desc)

CompletableFuture<Void> send(String mailId, byte[] payload, Priority priority)

CompletableFuture<Dispatcher> subscribe(String mailId, MessageHandler handler,
                                         Priority priority,   // null = all
                                         String queueGroup)

CompletableFuture<List<MessageMeta>> list(String mailId)
// MessageMeta: getMsgId(), getPriority(), getTs()

CompletableFuture<Void> delete(String mailId, String msgId)

Priority

Priority.CRITICAL  // "critical" — highest
Priority.URGENT    // "urgent"
Priority.NORMAL    // "normal" — default, no suffix

Public mailbox

Mailbox pub = client.createPublic(3600, "task.queue", "Tasks").get();
// pub.getMailId() == "task.queue"

Queue group

client.subscribe(mailId, handler, null, "workers").get();