PushObserver

```
public interface PushObserver

                    
```
HTTP/2 only. Processes server-initiated HTTP requests on the client. Implementations must quickly dispatch callbacks to avoid creating a bottleneck.
While onReset may occur at any time, the following callbacks are expected in order, correlated by stream ID.
- onRequest
- onHeaders (unless canceled)
- onData (optional sequence of data frames)
As a stream ID is scoped to a single HTTP/2 connection, implementations which target multiple connections should expect repetition of stream IDs.
Return true to request cancellation of a pushed stream. Note that this does not guarantee future frames won't arrive on the stream ID.

Method Summary

Modifier and Type	Method	Description
`abstract boolean`	`onRequest(int streamId, List<Header> requestHeaders)`	Describes the request that the server intends to push a response for.
`abstract boolean`	`onHeaders(int streamId, List<Header> responseHeaders, boolean last)`	The response headers corresponding to a pushed request.
`abstract boolean`	`onData(int streamId, BufferedSource source, int byteCount, boolean last)`	A chunk of response data corresponding to a pushed request.
`abstract void`	`onReset(int streamId, ErrorCode errorCode)`	Indicates the reason why this stream was canceled.

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

- Method Detail
  - onRequest
```
 abstract boolean onRequest(int streamId, List<Header> requestHeaders)
```
    Describes the request that the server intends to push a response for.
    
    Parameters:
    
    streamId - server-initiated stream ID: an even number.
    
    requestHeaders - minimally includes {@code :method}, {@code :scheme}, {@code :authority},and {@code :path}.
  - onHeaders
```
 abstract boolean onHeaders(int streamId, List<Header> responseHeaders, boolean last)
```
    The response headers corresponding to a pushed request. When {@code last} is true, there areno data frames to follow.
    
    Parameters:
    
    streamId - server-initiated stream ID: an even number.
    
    responseHeaders - minimally includes {@code :status}.
    
    last - when true, there is no response data.
  - onData
```
 abstract boolean onData(int streamId, BufferedSource source, int byteCount, boolean last)
```
    A chunk of response data corresponding to a pushed request. This data must either be read orskipped.
    
    Parameters:
    
    streamId - server-initiated stream ID: an even number.
    
    source - location of data corresponding with this stream ID.
    
    byteCount - number of bytes to read or skip from the source.
    
    last - when true, there are no data frames to follow.
  - onReset
```
 abstract void onReset(int streamId, ErrorCode errorCode)
```
    Indicates the reason why this stream was canceled.