org.apache.pulsar.client.api

Interface Reader<T>

All Superinterfaces:

AutoCloseable, Closeable

public interface Reader<T>
extends Closeable

A Reader can be used to scan through all the messages currently available in a topic.

Method Summary

Modifier and Type	Method and Description
CompletableFuture<Void>	closeAsync() Asynchronously close the reader and stop the broker to push more messages
String	getTopic()
boolean	hasMessageAvailable() Check if there is any message available to read from the current position.
CompletableFuture<Boolean>	hasMessageAvailableAsync() Asynchronously Check if there is message that has been published successfully to the broker in the topic.
boolean	hasReachedEndOfTopic() Return true if the topic was terminated and this reader has reached the end of the topic
boolean	isConnected()
Message<T>	readNext() Read the next message in the topic
Message<T>	readNext(int timeout, TimeUnit unit) Read the next message in the topic waiting for a maximum of timeout time units.
CompletableFuture<Message<T>>	readNextAsync()

Methods inherited from interface Closeable

close

Method Detail

getTopic

String getTopic()

Returns:

the topic from which this reader is reading from

readNext

Message<T> readNext()
             throws PulsarClientException

Read the next message in the topic

Returns:

the next messasge

Throws:

PulsarClientException

readNext

Message<T> readNext(int timeout,
                    TimeUnit unit)
             throws PulsarClientException

Read the next message in the topic waiting for a maximum of timeout time units. Returns null if no message is recieved in that time.

Returns:

the next message(Could be null if none received in time)

Throws:

PulsarClientException

readNextAsync

CompletableFuture<Message<T>> readNextAsync()

closeAsync

CompletableFuture<Void> closeAsync()

Asynchronously close the reader and stop the broker to push more messages

Returns:

a future that can be used to track the completion of the operation

hasReachedEndOfTopic

boolean hasReachedEndOfTopic()

Return true if the topic was terminated and this reader has reached the end of the topic

hasMessageAvailable

boolean hasMessageAvailable()
                     throws PulsarClientException

Check if there is any message available to read from the current position.

Throws:

PulsarClientException

hasMessageAvailableAsync

CompletableFuture<Boolean> hasMessageAvailableAsync()

Asynchronously Check if there is message that has been published successfully to the broker in the topic.

isConnected

boolean isConnected()

Returns:

Whether the reader is connected to the broker