Have Routes Support Multiple URIs

It would be nice if a route could be configured to make requests to multiple URIs and then return the results to a specified controller to aggregate the responses.

spring:
  application:
    name: gateway
  cloud:
    gateway:
      routes:
      # =====================================
      - id: greeting
        uris: 
        - lb://greeting
        - lb://name
        predicates:
        - Path=/greeting/**
        controller: blah

The controller, blah in this case, would take the result of calling the greeting and name services and return a response for the client.

For example if the greeting service returned Hello and the name service returned Ryan. The controller would return Hello Ryan.

Start by reviewing the route configuration shown in the issue and how requests are dispatched to a specified controller. The issue names no source files or tests, so the relevant route and controller entry points must be located first. Done means a route can call multiple configured URIs and return an aggregated response such as “Hello Ryan”.