org.springframework.boot.devtools.tunnel.server

Class HttpTunnelServer

java.lang.Object

org.springframework.boot.devtools.tunnel.server.HttpTunnelServer

public class HttpTunnelServer
extends Object

A server that can be used to tunnel TCP traffic over HTTP. Similar in design to the Bidirectional-streams Over Synchronous HTTP (BOSH) XMPP extension protocol, the server uses long polling with HTTP requests held open until a response is available. A typical traffic pattern would be as follows:

 [ CLIENT ]                      [ SERVER ]
     | (a) Initial empty request     |
     |------------------------------>|
     | (b) Data I                    |
  -->|------------------------------>|--->
     | Response I (a)                |
  <--|<------------------------------|<---
     |                               |
     | (c) Data II                   |
  -->|------------------------------>|--->
     | Response II (b)               |
  <--|<------------------------------|<---
     .                               .
     .                               .
 

Each incoming request is held open to be used to carry the next available response. The server will hold at most two connections open at any given time.

Requests should be made using HTTP GET or POST (depending if there is a payload), with any payload contained in the body. The following response codes can be returned from the server:

Status	Meaning
200 (OK)	Data payload response.
204 (No Content)	The long poll has timed out and the client should start a new request.
429 (Too many requests)	There are already enough connections open, this one can be dropped.
410 (Gone)	The target server has disconnected.
503 (Service Unavailable)	The target server is unavailable

Requests and responses that contain payloads include a x-seq header that contains a running sequence number (used to ensure data is applied in the correct order). The first request containing a payload should have a x-seq value of 1.

Since:

1.3.0

Author:

Phillip Webb, Andy Wilkinson

See Also:

HttpTunnelConnection

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	HttpTunnelServer.HttpConnection Encapsulates a HTTP request/response pair.
protected class	HttpTunnelServer.ServerThread The main server thread used to transfer tunnel traffic.

Constructor Summary

Constructors

Constructor and Description
HttpTunnelServer(TargetServerConnection serverConnection) Creates a new HttpTunnelServer instance.

Method Summary

Modifier and Type	Method and Description
protected HttpTunnelServer.ServerThread	getServerThread() Returns the active server thread, creating and starting it if necessary.
protected void	handle(HttpTunnelServer.HttpConnection httpConnection) Handle an incoming HTTP connection.
void	handle(org.springframework.http.server.ServerHttpRequest request, org.springframework.http.server.ServerHttpResponse response) Handle an incoming HTTP connection.
void	setDisconnectTimeout(long disconnectTimeout) Set the maximum amount of time to wait for a client before closing the connection.
void	setLongPollTimeout(int longPollTimeout) Set the long poll timeout for the server.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

HttpTunnelServer

public HttpTunnelServer(TargetServerConnection serverConnection)

Creates a new HttpTunnelServer instance.

Parameters:

serverConnection - the connection to the target server

Method Detail

handle

public void handle(org.springframework.http.server.ServerHttpRequest request,
                   org.springframework.http.server.ServerHttpResponse response)
            throws IOException

Handle an incoming HTTP connection.

Parameters:

request - the HTTP request

response - the HTTP response

Throws:

IOException - in case of I/O errors

handle

protected void handle(HttpTunnelServer.HttpConnection httpConnection)
               throws IOException

Handle an incoming HTTP connection.

Parameters:

httpConnection - the HTTP connection

Throws:

IOException - in case of I/O errors

getServerThread

protected HttpTunnelServer.ServerThread getServerThread()
                                                 throws IOException

Returns the active server thread, creating and starting it if necessary.

Returns:

the ServerThread (never null)

Throws:

IOException - in case of I/O errors

setLongPollTimeout

public void setLongPollTimeout(int longPollTimeout)

Set the long poll timeout for the server.

Parameters:

longPollTimeout - the long poll timeout in milliseconds

setDisconnectTimeout

public void setDisconnectTimeout(long disconnectTimeout)

Set the maximum amount of time to wait for a client before closing the connection.

Parameters:

disconnectTimeout - the disconnect timeout in milliseconds