Package com.hivemq.client.mqtt.lifecycle

Interface MqttClientReconnector

All Known Subinterfaces:

Mqtt3ClientReconnector, Mqtt5ClientReconnector

@DoNotImplement
public interface MqttClientReconnector

A reconnector is supplied by a MqttClientDisconnectedContext and can be used for reconnecting.

The client will reconnect only if at least one of the methods reconnect(boolean) or reconnectWhen(CompletableFuture, BiConsumer) is called.

All methods must only be called in MqttClientDisconnectedListener.onDisconnected(MqttClientDisconnectedContext). Some methods can also be called in the callback supplied to reconnectWhen(CompletableFuture, BiConsumer).

Since:

1.1

Field Summary

Fields

Modifier and Type	Field	Description
static final long	DEFAULT_DELAY_MS	Default delay in milliseconds the client will wait for before trying to reconnect.
static final boolean	DEFAULT_RECONNECT	If reconnect is enabled by default.
static final boolean	DEFAULT_REPUBLISH_IF_SESSION_EXPIRED	If republish when the session expired before the client reconnected successfully is enabled by default.
static final boolean	DEFAULT_RESUBSCRIBE_IF_SESSION_EXPIRED	If resubscribe when the session expired before the client reconnected successfully is enabled by default.
static final boolean	DEFAULT_RESUBSCRIBE_IF_SESSION_PRESENT	If resubscribe when the session is present when the client reconnected successfully is enabled by default.

Method Summary

Modifier and Type	Method	Description
@NotNull MqttClientReconnector	delay(long delay, @NotNull TimeUnit timeUnit)	Sets a delay the client will wait for before trying to reconnect.
int	getAttempts()
long	getDelay(@NotNull TimeUnit timeUnit)	Returns the currently set delay the client will wait for before trying to reconnect.
@NotNull MqttClientTransportConfig	getTransportConfig()	Returns the currently set transport configuration the client will try to reconnect with.
boolean	isReconnect()
boolean	isRepublishIfSessionExpired()
boolean	isResubscribeIfSessionExpired()
boolean	isResubscribeIfSessionPresent()
@NotNull MqttClientReconnector	reconnect(boolean reconnect)	Instructs the client to reconnect or not.
<T> @NotNull MqttClientReconnector	reconnectWhen(@NotNull CompletableFuture<T> future, @Nullable BiConsumer<? super T,? super Throwable> callback)	Instructs the client to reconnect after a future completes.
@NotNull MqttClientReconnector	republishIfSessionExpired(boolean republish)	Instructs the client to queue pending Publish messages and automatically publish them even if the session expired before reconnected successfully.
@NotNull MqttClientReconnector	resubscribeIfSessionExpired(boolean resubscribe)	Instructs the client to automatically restore its subscriptions when the session expired before it reconnected successfully.
@NotNull MqttClientReconnector	resubscribeIfSessionPresent(boolean resubscribeIfSessionPresent)	Instructs the client to automatically restore its subscriptions when reconnected successfully and the session is still present.
@NotNull MqttClientTransportConfigBuilder.Nested<? extends MqttClientReconnector>	transportConfig()	Fluent counterpart of transportConfig(MqttClientTransportConfig).
@NotNull MqttClientReconnector	transportConfig(@NotNull MqttClientTransportConfig transportConfig)	Sets a different transport configuration the client will try to reconnect with.

Field Details

DEFAULT_RECONNECT

static final boolean DEFAULT_RECONNECT

If reconnect is enabled by default.

Since:

1.2

See Also:

• Constant Field Values

DEFAULT_RESUBSCRIBE_IF_SESSION_PRESENT

static final boolean DEFAULT_RESUBSCRIBE_IF_SESSION_PRESENT

If resubscribe when the session is present when the client reconnected successfully is enabled by default.

Since:

1.3.7

See Also:

• Constant Field Values

DEFAULT_RESUBSCRIBE_IF_SESSION_EXPIRED

static final boolean DEFAULT_RESUBSCRIBE_IF_SESSION_EXPIRED

If resubscribe when the session expired before the client reconnected successfully is enabled by default.

Since:

1.2

See Also:

• Constant Field Values

DEFAULT_REPUBLISH_IF_SESSION_EXPIRED

static final boolean DEFAULT_REPUBLISH_IF_SESSION_EXPIRED

If republish when the session expired before the client reconnected successfully is enabled by default.

Since:

1.2

See Also:

• Constant Field Values

DEFAULT_DELAY_MS

static final long DEFAULT_DELAY_MS

Default delay in milliseconds the client will wait for before trying to reconnect.

Since:

1.2

See Also:

• Constant Field Values

Method Details

getAttempts

int getAttempts()

Returns:

the number of failed connection attempts.

reconnect

@NotNull
@NotNull MqttClientReconnector reconnect(boolean reconnect)

Instructs the client to reconnect or not.

Parameters:

reconnect - whether to reconnect.

Returns:

this reconnector.

reconnectWhen

@NotNull
<T> @NotNull MqttClientReconnector reconnectWhen(@NotNull
 @NotNull CompletableFuture<T> future,
 @Nullable
 @Nullable BiConsumer<? super T,? super Throwable> callback)

Instructs the client to reconnect after a future completes.

If additionally a delay is supplied, the client will reconnect after both are complete.

This method must only be called in MqttClientDisconnectedListener.onDisconnected(MqttClientDisconnectedContext) and not in the supplied callback.

Type Parameters:

T - the result type of the future.

Parameters:

future - the client will reconnect only after the future completes.

callback - the callback that will be called after the future completes and before the client will reconnect. It can be used to set new connect properties (e.g. credentials).

Returns:

this reconnector.

Throws:

UnsupportedOperationException - if called outside of MqttClientDisconnectedListener.onDisconnected(MqttClientDisconnectedContext).

isReconnect

boolean isReconnect()

Returns:

whether the client will reconnect.

resubscribeIfSessionPresent

@NotNull
@NotNull MqttClientReconnector resubscribeIfSessionPresent(boolean resubscribeIfSessionPresent)

Instructs the client to automatically restore its subscriptions when reconnected successfully and the session is still present.

When the client reconnected successfully and its session is still present, the server still knows its subscriptions, so resubscribing is optional.

This setting only has effect if the client will reconnect (at least one of the methods reconnect(boolean) or reconnectWhen(CompletableFuture, BiConsumer) is called).

This method must only be called in MqttClientDisconnectedListener.onDisconnected(MqttClientDisconnectedContext) and not in the callback supplied to reconnectWhen(CompletableFuture, BiConsumer).

Parameters:

resubscribeIfSessionPresent - whether to resubscribe if the session is present when the client reconnected successfully.

Returns:

this reconnector.

Throws:

UnsupportedOperationException - if called outside of MqttClientDisconnectedListener.onDisconnected(MqttClientDisconnectedContext).

Since:

1.3.7

isResubscribeIfSessionPresent

boolean isResubscribeIfSessionPresent()

Returns:

whether the client will resubscribe if the session is present when it reconnects successfully.

Since:

1.3.7

resubscribeIfSessionExpired

@NotNull
@NotNull MqttClientReconnector resubscribeIfSessionExpired(boolean resubscribe)

Instructs the client to automatically restore its subscriptions when the session expired before it reconnected successfully.

When the client reconnected successfully and its session is still present, the server still knows its subscriptions and they do not need to be restored.

This setting only has effect if the client will reconnect (at least one of the methods reconnect(boolean) or reconnectWhen(CompletableFuture, BiConsumer) is called).

This method must only be called in MqttClientDisconnectedListener.onDisconnected(MqttClientDisconnectedContext) and not in the callback supplied to reconnectWhen(CompletableFuture, BiConsumer).

Parameters:

resubscribe - whether to resubscribe when the session expired before the client reconnected successfully.

Returns:

this reconnector.

Throws:

UnsupportedOperationException - if called outside of MqttClientDisconnectedListener.onDisconnected(MqttClientDisconnectedContext).

Since:

1.2

isResubscribeIfSessionExpired

boolean isResubscribeIfSessionExpired()

Returns:

whether the client will resubscribe when the session expired before it reconnected successfully.

Since:

1.2

republishIfSessionExpired

@NotNull
@NotNull MqttClientReconnector republishIfSessionExpired(boolean republish)

Instructs the client to queue pending Publish messages and automatically publish them even if the session expired before reconnected successfully.

When the client reconnected successfully and its session is still present, the client will always queue pending Publish messages and automatically publish them to ensure the QoS guarantees.

This setting only has effect if the client will reconnect (at least one of the methods reconnect(boolean) or reconnectWhen(CompletableFuture, BiConsumer) is called).

This method must only be called in MqttClientDisconnectedListener.onDisconnected(MqttClientDisconnectedContext) and not in the callback supplied to reconnectWhen(CompletableFuture, BiConsumer).

Parameters:

republish - whether to republish when the session expired before the client reconnected successfully.

Returns:

this reconnector.

Throws:

UnsupportedOperationException - if called outside of MqttClientDisconnectedListener.onDisconnected(MqttClientDisconnectedContext).

Since:

1.2

isRepublishIfSessionExpired

boolean isRepublishIfSessionExpired()

Returns:

whether the client will republish when the session expired before it reconnected successfully.

Since:

1.2

delay

@NotNull
@NotNull MqttClientReconnector delay(long delay,
 @NotNull
 @NotNull TimeUnit timeUnit)

Sets a delay the client will wait for before trying to reconnect.

This setting only has effect if the client will reconnect (at least one of the methods reconnect(boolean) or reconnectWhen(CompletableFuture, BiConsumer) is called).

If additionally a future is supplied, the client will reconnect after both are complete.

This method must only be called in MqttClientDisconnectedListener.onDisconnected(MqttClientDisconnectedContext) and not in the callback supplied to reconnectWhen(CompletableFuture, BiConsumer).

Parameters:

delay - delay which the client will wait before trying to reconnect.

timeUnit - the time unit of the delay.

Returns:

this reconnector.

Throws:

UnsupportedOperationException - if called outside of MqttClientDisconnectedListener.onDisconnected(MqttClientDisconnectedContext).

getDelay

long getDelay(@NotNull
 @NotNull TimeUnit timeUnit)

Returns the currently set delay the client will wait for before trying to reconnect.

If the delay(long, TimeUnit) method has not been called before (including previous MqttClientDisconnectedListeners) it will be DEFAULT_DELAY_MS.

Parameters:

timeUnit - the time unit of the returned delay.

Returns:

the delay in the given time unit.

transportConfig

@NotNull
@NotNull MqttClientReconnector transportConfig(@NotNull
 @NotNull MqttClientTransportConfig transportConfig)

Sets a different transport configuration the client will try to reconnect with.

Parameters:

transportConfig - the transport configuration the client will try to reconnect with.

Returns:

this reconnector.

transportConfig

@CheckReturnValue
@NotNull MqttClientTransportConfigBuilder.Nested<? extends MqttClientReconnector> transportConfig()

Fluent counterpart of transportConfig(MqttClientTransportConfig).

Calling MqttClientTransportConfigBuilder.Nested.applyTransportConfig() on the returned builder has the effect of extending the current transport configuration.

Returns:

the fluent builder for the transport configuration.

See Also:

• transportConfig(MqttClientTransportConfig)

getTransportConfig

@NotNull
@NotNull MqttClientTransportConfig getTransportConfig()

Returns the currently set transport configuration the client will try to reconnect with.

If the transportConfig(MqttClientTransportConfig) method has not been called before (including previous MqttClientDisconnectedListeners) it will be the transport configuration the client was connected with or the default transport configuration if it has not been connected yet.

Returns:

the transport configuration.