Package org.bluezoo.gumdrop.mqtt.client

Class MQTTClient

java.lang.Object

org.bluezoo.gumdrop.mqtt.client.MQTTClient

public class MQTTClient
extends Object

High-level MQTT client facade.

Provides a simple API for connecting to MQTT brokers. Internally creates a TCPTransportFactory, ClientEndpoint, and MQTTClientProtocolHandler, following the same pattern as SMTPClient.

Usage

 MQTTClient client = new MQTTClient("broker.example.com", 1883);
 client.setClientId("myClient");
 client.connect(new MQTTClientCallback() {
     public void connected(boolean sessionPresent, int returnCode) {
         client.subscribe("sensors/#", QoS.AT_LEAST_ONCE);
     }
     public void connectionLost(Exception cause) { ... }
     public void subscribeAcknowledged(int id, int[] qos) { ... }
     public void publishComplete(int id) { ... }
 }, (topic, payload, qos, retain) -> {
     System.out.println("Received: " + topic);
 });
 

Author:

Chris Burdess

See Also:

• MQTTClientProtocolHandler
• MQTTClientCallback

Constructor Summary

Constructors

Constructor	Description
MQTTClient(String host, int port)
MQTTClient(InetAddress host, int port)
MQTTClient(SelectorLoop selectorLoop, String host, int port)
MQTTClient(SelectorLoop selectorLoop, InetAddress host, int port)

Method Summary

Modifier and Type	Method	Description
void	connect(MQTTClientCallback callback, MQTTMessageListener messageListener)	Connects to the MQTT broker.
void	disconnect()	Sends DISCONNECT and closes the connection.
int	publish(String topic, byte[] payload, QoS qos, boolean retain)	Publishes a message to a topic.
int	publish(String topic, String payload, QoS qos)	Publishes a UTF-8 string message.
void	setCleanSession(boolean cleanSession)
void	setClientId(String clientId)
void	setCredentials(String username, String password)
void	setKeepAlive(int keepAlive)
void	setKeystoreFile(Path path)
void	setKeystorePass(String pass)
void	setMessageStore(MQTTMessageStore messageStore)
void	setSecure(boolean secure)
void	setSSLContext(SSLContext context)
void	setTrustManager(X509TrustManager trustManager)
void	setVersion(MQTTVersion version)
void	setWill(String topic, byte[] payload, QoS qos, boolean retain)
int	subscribe(String[] topicFilters, QoS[] qosLevels)	Subscribes to multiple topic filters.
int	subscribe(String topicFilter, QoS qos)	Subscribes to a single topic filter.
int	unsubscribe(String... topicFilters)	Unsubscribes from topic filters.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

MQTTClient

public MQTTClient(String host,
 int port)

MQTTClient

public MQTTClient(SelectorLoop selectorLoop,
 String host,
 int port)

MQTTClient

public MQTTClient(InetAddress host,
 int port)

MQTTClient

public MQTTClient(SelectorLoop selectorLoop,
 InetAddress host,
 int port)

Method Details

setSecure

public void setSecure(boolean secure)

setSSLContext

public void setSSLContext(SSLContext context)

setTrustManager

public void setTrustManager(X509TrustManager trustManager)

setKeystoreFile

public void setKeystoreFile(Path path)

setKeystorePass

public void setKeystorePass(String pass)

setVersion

public void setVersion(MQTTVersion version)

setClientId

public void setClientId(String clientId)

setCleanSession

public void setCleanSession(boolean cleanSession)

setKeepAlive

public void setKeepAlive(int keepAlive)

setCredentials

public void setCredentials(String username,
 String password)

setMessageStore

public void setMessageStore(MQTTMessageStore messageStore)

setWill

public void setWill(String topic,
 byte[] payload,
 QoS qos,
 boolean retain)

connect

public void connect(MQTTClientCallback callback,
 MQTTMessageListener messageListener)
             throws IOException

Connects to the MQTT broker.

Parameters:

callback - lifecycle callback

messageListener - message delivery callback

Throws:

IOException - if the transport cannot be created

publish

public int publish(String topic,
 byte[] payload,
 QoS qos,
 boolean retain)

Publishes a message to a topic.

Returns:

the packet ID (0 for QoS 0)

publish

public int publish(String topic,
 String payload,
 QoS qos)

Publishes a UTF-8 string message.

subscribe

public int subscribe(String topicFilter,
 QoS qos)

Subscribes to a single topic filter.

Returns:

the packet ID

subscribe

public int subscribe(String[] topicFilters,
 QoS[] qosLevels)

Subscribes to multiple topic filters.

Returns:

the packet ID

unsubscribe

public int unsubscribe(String... topicFilters)

Unsubscribes from topic filters.

Returns:

the packet ID

disconnect

public void disconnect()

Sends DISCONNECT and closes the connection.