In Eclipse Vert.x , while using Vert.x Web, applying session handler to the router, allows us to access the session using RoutingContext , in the handler. Is there any way we can access the session using ProxyContext , which is used in ProxyInterceptor implementation?
In Eclipse Vert.x, when using Vert.x Web and applying a SessionHandler
to your router, session information becomes accessible through the RoutingContext
(via routingContext.session()
).
However, when you’re working with service proxies (like ProxyInterceptor
), the context you’re dealing with is a ProxyContext
, not a RoutingContext
.
Problem
You’re asking if it’s possible to access the HTTP session from ProxyContext
— and the short answer is:
No, not directly.
ProxyContext
is not tied to the HTTP layer — it’s designed for event bus communication, and does not expose the underlying HTTP request or session data fromRoutingContext
.
Why This Happens
The session is part of the HTTP layer managed by RoutingContext
. Once a request is proxied over the event bus (as it is with Vert.x service proxies), the context becomes abstracted away from the HTTP request/session.
The event bus handler (e.g., the service proxy implementation or ProxyInterceptor
) receives only:
- Serialized method arguments
- Delivery options (metadata, headers, etc.)
ProxyContext
, which may contain some metadata but not the session
Workarounds / Alternatives
If you need to pass session-related data to your service proxy, consider these approaches:
1. Pass Required Session Attributes Explicitly
Before calling the service proxy, extract values from the session and pass them as parameters:
String userId = routingContext.session().get("userId");
myServiceProxy.doSomething(userId, otherParams, handler);
Then in your proxy or interceptor, handle it accordingly.
2. Pass Session Info in Event Bus Metadata
You can add session-derived metadata (e.g., user roles, tokens, etc.) to DeliveryOptions.headers()
:
DeliveryOptions opts = new DeliveryOptions();
opts.addHeader("userId", routingContext.session().get("userId"));
proxyClient.send(someAddress, payload, opts);
Then access it in the proxy interceptor via context.headers()
.
3. Use Vert.x Context Local Storage
If you’re in the same Vert.x context (same event loop), you can use LocalMap
:
routingContext.vertx().getOrCreateContext().put("userId", userId);
Then access it from any handler running in the same context (note: not across event bus boundaries).
Why Not Just Inject the RoutingContext
?
Because ProxyContext
is part of the Vert.x Service Proxy system, it doesn’t have access to HTTP-layer constructs. There’s no built-in way to map a ProxyContext
back to the original HTTP RoutingContext
.
Conclusion
You cannot access the HTTP session directly from ProxyContext
. Instead:
- Extract needed values from the session in
RoutingContext
- Pass them explicitly (as parameters or headers) when calling the proxy
Let me know if you want a sample implementation of passing session values via event bus headers.