Disconnect

You can disconnect a MQTT client without the need to provide arguments. This will use the default parameters as defined in the MQTT specification or reasonable defaults if not defined there.

client.disconnect();

The return type depends on the used MQTT version and API flavour.

- The blocking API for disconnect has a Void return value since disconnects in MQTT are sent only with no response defined.
```
client.disconnect();
```
- The asynchronous API returns a CompletableFuture which completes with a Void return value.
```
CompletableFuture<Void> disconnectFuture = client.disconnect();
```
- The reactive API returns a Single which succeeds with a Void return since no response is expected. As the Single is a reactive type, the following line does not disconnect immediately but only after you subscribe to it (in terms of Reactive Streams).
```
Single<Void> disconnectSingle = client.connect();
```
- The blocking API for disconnect has a Void return value since disconnects in MQTT are sent only with no response defined.
```
client.disconnect();
```
- The asynchronous API returns a CompletableFuture which completes with a Void return value.
```
CompletableFuture<Void> disconnectFuture = client.disconnect();
```
- The reactive API returns a Single which succeeds with a Void return since no response is expected. As the Single is a reactive type, the following line does not disconnect immediately but only after you subscribe to it (in terms of Reactive Streams).
```
Single<Void> disconnectSingle = client.connect();
```

The rest of this section describes all possible properties of a Mqtt5Disconnect message. They can be set via a fluent builder API.

Mqtt5Disconnect disconnectMessage = Mqtt5Disconnect.builder()
        ... // here you can specify multiple properties described below
        .send();

Mqtt5Disconnect disconnectMessage = Mqtt5Disconnect.builder()
        ... // here you can specify multiple properties described below
        .build();

client.disconnect(disconnectMessage);

Mqtt5Disconnect disconnectMessage = Mqtt5Disconnect.builder()
        ... // here you can specify multiple properties described below
        .send();

Mqtt5Disconnect disconnectMessage = Mqtt5Disconnect.builder()
        ... // here you can specify multiple properties described below
        .build();

CompletableFuture<Void> disconnectFuture = client.disconnect(disconnectMessage);

Mqtt5Disconnect disconnectMessage = Mqtt5Disconnect.builder()
        ... // here you can specify multiple properties described below
        .applyDisconnect();

Mqtt5Disconnect disconnectMessage = Mqtt5Disconnect.builder()
        ... // here you can specify multiple properties described below
        .build();

Single<Void> disconnectSingle = client.disconnect(disconnectMessage);

The Disconnect call for MQTT 3.1.1 does not support any properties.

Disconnect Properties
See Also: Mqtt5DisconnectBuilderBase
Reason Code
The reason code of a disconnect message indicates to the broker the reason for the disconnect. This can be used to trigger broker behavior.
Property Values Default MQTT Specification
reasonCode See Mqtt5DisconnectReasonCode NORMAL_DISCONNECTION 3.14.2.1
- Fluent
- Prebuilt message
- ```
client.disconnectWith().reasonCode(Mqtt5DisconnectReasonCode.DISCONNECT_WITH_WILL_MESSAGE)...;
```
- ```
Mqtt5Disconnect disconnectMessage = Mqtt5Disconnect.builder()
    .reasonCode(Mqtt5DisconnectReasonCode.DISCONNECT_WITH_WILL_MESSAGE)...build();
```
Session Expiry Interval
The session expiry interval is the time interval (in seconds) the session will persist when the client is disconnected.
Property Values Default MQTT Specification
sessionExpiryInterval [0 - 4_294_967_295] N/A 3.14.2.2.2
If the Session Expiry Interval is absent, the Session Expiry Interval in the CONNECT packet is used.
- Fluent
- Prebuilt message
- ```
client.disconnectWith().sessionExpiryInterval(100)...;
```
- ```
Mqtt5Disconnect disconnectMessage = Mqtt5Disconnect.builder().sessionExpiryInterval(100)...build();
```
Session expiry can be disabled by setting it to 4_294_967_295 or using the method noSessionExpiry.
- ```
client.disconnectWith().noSessionExpiry()...;
```
- ```
Mqtt5Disconnect disconnectMessage = Mqtt5Disconnect.builder().noSessionExpiry()...build();
```
Additional Resources
MQTT 5 Essentials - Session and Message Expiry Intervals

Property	Values	Default	MQTT Specification
`reasonCode`	See Mqtt5DisconnectReasonCode	`NORMAL_DISCONNECTION`	3.14.2.1

Property	Values	Default	MQTT Specification
`sessionExpiryInterval`	[`0` - `4_294_967_295`]	N/A	3.14.2.2.2

User Properties

User Properties are user defined name and value pairs which are sent with the Mqtt5Disconnect message.

Method	Values	MQTT Specification
`userProperties.add`	`String, String` `MqttUtf8String, MqttUtf8String` `Mqtt5UserProperty`	3.1.2.11.8

client.disconnectWith()
        .userProperties()
            .add("name1", "value1")
            .add(Mqtt5UserProperty.of("name2", "value2"))
            .applyUserProperties()
        ...

Mqtt5Disconnect disconnectMessage = Mqtt5Disconnect.builder()
        .userProperties()
            .add("name1", "value1")
            .add(Mqtt5UserProperty.of("name2", "value2"))
            .applyUserProperties()
        ...
        .build();

You can also prebuild the Mqtt5UserProperties.

Mqtt5UserProperties connectUserProperties = Mqtt5UserProperties.builder()
        .add("name1", "value1")
        .add(Mqtt5UserProperty.of("name2", "value2"))
        .build();

Mqtt5Disconnect disconnectMessage = Mqtt5Disconnect.builder()
        .userProperties(connectUserProperties)
        ...
        .build();

Additional Resources

MQTT 5 Essentials - User Properties

Disconnect

Disconnect Properties

Reason Code

Session Expiry Interval

User Properties