Subscribing with Filter Subject and JS context

pull-subscribe-filter-subject.go

package main

import (
	"fmt"
	"log"

	"github.com/nats-io/nats.go"
)

func main() {
	nc, err := nats.Connect("localhost")
	if err != nil {
		log.Fatal(err)
	}
	js, err := nc.JetStream()
	if err != nil {
		log.Fatal(err)
	}
	js.AddStream(&nats.StreamConfig{
		Name:     "foo",
		Subjects: []string{"foo.*"},
	})

	// Create durable pull subscriber (no delivery subject)
	_, err = js.AddConsumer("foo", &nats.ConsumerConfig{
		Durable:       "d-foo",
		FilterSubject: "foo.1",
		AckPolicy:     nats.AckExplicitPolicy,
	})
	if err != nil {
		log.Fatal(err)
	}

	// Send message that matches stream wildcard.
	js.Publish("foo.1", []byte("On foo.1"))

	// Receive all messages.
	js.Subscribe("foo.*", func(msg *nats.Msg) {
		fmt.Println("[Recvd on foo.*]", msg)
	})

	sub, err := js.PullSubscribe("foo.1", "d-foo", nats.BindStream("foo"))
	if err != nil {
		log.Fatal(err)
	}

	msgs, err := sub.Fetch(1)
	if err != nil {
		log.Fatal(err)
	}
	msg := msgs[0]
	fmt.Println("[Recvd on foo.1]", string(msg.Data))
}