ReaderImpl (TurtleQueue API)

java.lang.Object
- com.turtlequeue.ReaderImpl<T>

All Implemented Interfaces:: Reader<T>, Closeable, AutoCloseable

public class ReaderImpl<T>
extends Object
implements Reader<T>

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`close()`
`CompletableFuture<Void>`	`closeAsync()` Asynchronously close the reader and stop the broker to push more messages.
`Topic`	`getTopic()`
`CompletableFuture<Boolean>`	`hasMessageAvailable()` Asynchronously check if there is any message available to read from the current position.
`boolean`	`hasReachedEndOfTopic()` Return true if the topic was terminated and this reader has reached the end of the topic.
`boolean`	`isConnected()`
`CompletableFuture<Message<T>>`	`readNext()` Read asynchronously the next message in the topic.
`CompletableFuture<Void>`	`seek(long timestamp)` Reset the subscription associated with this reader to a specific message publish time.
`CompletableFuture<Void>`	`seek(MessageId messageId)` Reset the subscription associated with this reader to a specific message id.
`CompletableFuture<Reader<T>>`	`subscribeReturn()`
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Method Detail
  - getTopic
```
public Topic getTopic()
```
    Specified by:
    
    getTopic in interface Reader<T>
    
    Returns:
    
    the topic from which this reader is reading from
  - readNext
```
public CompletableFuture<Message<T>> readNext()
```
    Description copied from interface: Reader
    
    Read asynchronously the next message in the topic.
    readNextAsync() should be called subsequently once returned CompletableFuture gets complete with received message. Else it creates backlog of receive requests in the application.
    The returned future can be cancelled before completion by calling .cancel(false) (CompletableFuture.cancel(boolean)) to remove it from the the backlog of receive requests. Another choice for ensuring a proper clean up of the returned future is to use the CompletableFuture.orTimeout method which is available on JDK9+. That would remove it from the backlog of receive requests if receiving exceeds the timeout.
    
    Specified by:
    
    readNext in interface Reader<T>
    
    Returns:
    
    a future that will yield a message (when it's available) or PulsarClientException if the reader is already closed.
  - closeAsync
```
public CompletableFuture<Void> closeAsync()
```
    Description copied from interface: Reader
    
    Asynchronously close the reader and stop the broker to push more messages.
    
    Specified by:
    
    closeAsync in interface Reader<T>
    
    Returns:
    
    a future that can be used to track the completion of the operation
  - close
```
public void close()
```
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in interface AutoCloseable
  - hasReachedEndOfTopic
```
public boolean hasReachedEndOfTopic()
```
    Description copied from interface: Reader
    
    Return true if the topic was terminated and this reader has reached the end of the topic.
    Note that this only applies to a "terminated" topic (where the topic is "sealed" and no more messages can be published) and not just that the reader is simply caught up with the publishers. Use Reader.hasMessageAvailable() to check for for that.
    
    Specified by:
    
    hasReachedEndOfTopic in interface Reader<T>
  - hasMessageAvailable
```
public CompletableFuture<Boolean> hasMessageAvailable()
```
    Description copied from interface: Reader
    
    Asynchronously check if there is any message available to read from the current position.
    This check can be used by an application to scan through a topic and stop when the reader reaches the current last published message.
    Even if this call returns true, that will not guarantee that a subsequent call to Reader.readNext() will not block.
    
    Specified by:
    
    hasMessageAvailable in interface Reader<T>
    
    Returns:
    
    a future that will yield true if the are messages available to be read, false otherwise, or a PulsarClientException if there was any error in the operation
  - isConnected
```
public boolean isConnected()
```
    Specified by:
    
    isConnected in interface Reader<T>
    
    Returns:
    
    Whether the reader is connected to the broker
  - seek
```
public CompletableFuture<Void> seek(MessageId messageId)
```
    Description copied from interface: Reader
    Reset the subscription associated with this reader to a specific message id.
    The message id can either be a specific message or represent the first or last messages in the topic.
    - MessageId.earliest : Reset the reader on the earliest message available in the topic
    - MessageId.latest : Reset the reader on the latest message in the topic
    Note: this operation can only be done on non-partitioned topics. For these, one can rather perform the seek() on the individual partitions.
    Specified by:
    
    seek in interface Reader<T>
    
    Parameters:
    
    messageId - the message id where to position the reader
    
    Returns:
    
    a future to track the completion of the seek operation
  - seek
```
public CompletableFuture<Void> seek(long timestamp)
```
    Description copied from interface: Reader
    
    Reset the subscription associated with this reader to a specific message publish time.
    Note: this operation can only be done on non-partitioned topics. For these, one can rather perform the seek() on the individual partitions.
    
    Specified by:
    
    seek in interface Reader<T>
    
    Parameters:
    
    timestamp - the message publish time where to position the reader
    
    Returns:
    
    a future to track the completion of the seek operation
  - subscribeReturn
```
public CompletableFuture<Reader<T>> subscribeReturn()
```
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class ReaderImpl<T>

Method Summary

Methods inherited from class java.lang.Object

Method Detail

getTopic

readNext

closeAsync

close

hasReachedEndOfTopic

hasMessageAvailable

isConnected

seek

seek

subscribeReturn

toString