ReadStream (Vert.x Stack Docs 4.5.22 API)

All Superinterfaces:

StreamBase

All Known Subinterfaces:

AmqpReceiver, AsyncFile, CassandraRowStream, ClientWebSocket, DatagramSocket, GrpcClientResponse<Req,Resp>, GrpcReadStream<T>, GrpcServerRequest<Req,Resp>, HttpClientResponse, HttpServerFileUpload, HttpServerRequest, JsonParser, KafkaConsumer<K,V>, KafkaReadStream<K,V>, MessageConsumer<T>, NetSocket, PgChannel, RabbitMQConsumer, ReactiveReadStream<T>, RecordParser, RedisConnection, RowStream<T>, ServerWebSocket, SockJSSocket, SQLRowStream, TestSuiteReport, TimeoutStream, WebServerRequest, WebSocket, WebSocketBase

All Known Implementing Classes:

ReadStreamSubscriber
```
public interface ReadStream<T>
extends StreamBase
```
Represents a stream of items that can be read from.
Any class that implements this interface can be used by a Pipe to pipe data from it to a WriteStream.

Streaming mode
The stream is either in flowing or fetch mode.
- When the stream is in flowing mode, elements are delivered to the handler.
- When the stream is in fetch mode, only the number of requested elements will be delivered to the handler.
The mode can be changed with the pause(), resume() and fetch(long) methods:
- Calling resume() sets the flowing mode
- Calling pause() sets the fetch mode and resets the demand to 0
- Calling fetch(long) requests a specific amount of elements and adds it to the actual demand
Author:

Tim Fox

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method and Description
`default <R,A> Future<R>`	`collect(java.util.stream.Collector<T,A,R> collector)` Apply a `collector` to this stream, the obtained result is returned as a future.
`ReadStream<T>`	`endHandler(Handler<Void> endHandler)` Set an end handler.
`ReadStream<T>`	`exceptionHandler(Handler<Throwable> handler)` Set an exception handler on the read stream.
`ReadStream<T>`	`fetch(long amount)` Fetch the specified `amount` of elements.
`ReadStream<T>`	`handler(Handler<T> handler)` Set a data handler.
`ReadStream<T>`	`pause()` Pause the `ReadStream`, it sets the buffer in `fetch` mode and clears the actual demand.
`default Pipe<T>`	`pipe()` Pause this stream and return a `Pipe` to transfer the elements of this stream to a destination `WriteStream`.
`default Future<Void>`	`pipeTo(WriteStream<T> dst)` Same as `pipeTo(WriteStream, Handler)` but returns a `Future` of the asynchronous result
`default void`	`pipeTo(WriteStream<T> dst, Handler<AsyncResult<Void>> handler)` Pipe this `ReadStream` to the `WriteStream`.
`ReadStream<T>`	`resume()` Resume reading, and sets the buffer in `flowing` mode.

- Method Detail
  - exceptionHandler
```
ReadStream<T> exceptionHandler(Handler<Throwable> handler)
```
    Set an exception handler on the read stream.
    
    Specified by:
    
    exceptionHandler in interface StreamBase
    
    Parameters:
    
    handler - the exception handler
    
    Returns:
    
    a reference to this, so the API can be used fluently
  - handler
```
ReadStream<T> handler(Handler<T> handler)
```
    Set a data handler. As data is read, the handler will be called with the data.
    
    Returns:
    
    a reference to this, so the API can be used fluently
  - pause
```
ReadStream<T> pause()
```
    Pause the ReadStream, it sets the buffer in fetch mode and clears the actual demand.
    While it's paused, no data will be sent to the data handler.
    
    Returns:
    
    a reference to this, so the API can be used fluently
  - resume
```
ReadStream<T> resume()
```
    Resume reading, and sets the buffer in flowing mode.
    If the ReadStream has been paused, reading will recommence on it.
    
    Returns:
    
    a reference to this, so the API can be used fluently
  - fetch
```
ReadStream<T> fetch(long amount)
```
    Fetch the specified amount of elements. If the ReadStream has been paused, reading will recommence with the specified amount of items, otherwise the specified amount will be added to the current stream demand.
    
    Returns:
    
    a reference to this, so the API can be used fluently
  - endHandler
```
ReadStream<T> endHandler(Handler<Void> endHandler)
```
    Set an end handler. Once the stream has ended, and there is no more data to be read, this handler will be called.
    
    Returns:
    
    a reference to this, so the API can be used fluently
  - pipe
```
default Pipe<T> pipe()
```
    Pause this stream and return a Pipe to transfer the elements of this stream to a destination WriteStream.
    The stream will be resumed when the pipe will be wired to a WriteStream.
    
    Returns:
    
    a pipe
  - pipeTo
```
default Future<Void> pipeTo(WriteStream<T> dst)
```
    Same as pipeTo(WriteStream, Handler) but returns a Future of the asynchronous result
  - pipeTo
```
default void pipeTo(WriteStream<T> dst,
                    Handler<AsyncResult<Void>> handler)
```
    Pipe this ReadStream to the WriteStream.
    Elements emitted by this stream will be written to the write stream until this stream ends or fails.
    Once this stream has ended or failed, the write stream will be ended and the handler will be called with the result.
    
    Parameters:
    
    dst - the destination write stream
  - collect
```
default <R,A> Future<R> collect(java.util.stream.Collector<T,A,R> collector)
```
    Apply a collector to this stream, the obtained result is returned as a future.
    Handlers of this stream are affected by this operation.
    
    Returns:
    
    a future notified with result produced by the collector applied to this stream

Interface ReadStream<T>

Streaming mode

Method Summary

Method Detail

exceptionHandler

handler

pause

resume

fetch

endHandler

pipe

pipeTo

pipeTo

collect