mirror of
https://github.com/nats-io/nats.go.git
synced 2025-09-27 04:46:01 +08:00
85 lines
2.1 KiB
Go
85 lines
2.1 KiB
Go
// Copyright 2022 The NATS Authors
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package micro
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import (
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"fmt"
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"log"
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"strconv"
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"time"
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"github.com/nats-io/nats.go"
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)
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func Example() {
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s := RunServerOnPort(-1)
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defer s.Shutdown()
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nc, err := nats.Connect(s.ClientURL())
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if err != nil {
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log.Fatal(err)
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}
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defer nc.Close()
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// Service handler is a function which takes Service.Request as argument.
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// req.Respond or req.Error should be used to respond to the request.
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incrementHandler := func(req *Request) error {
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val, err := strconv.Atoi(string(req.Data))
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if err != nil {
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req.Error("400", "request data should be a number", nil)
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return nil
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}
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responseData := val + 1
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req.Respond([]byte(strconv.Itoa(responseData)))
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return nil
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}
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config := Config{
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Name: "IncrementService",
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Version: "0.1.0",
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Description: "Increment numbers",
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Endpoint: Endpoint{
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// service handler
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Handler: incrementHandler,
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// a unique subject serving as a service endpoint
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Subject: "numbers.increment",
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},
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}
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// Multiple instances of the servcice with the same name can be created.
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// Requests to a service with the same name will be load-balanced.
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for i := 0; i < 5; i++ {
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svc, err := AddService(nc, config)
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if err != nil {
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log.Fatal(err)
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}
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defer svc.Stop()
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}
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// send a request to a service
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resp, err := nc.Request("numbers.increment", []byte("3"), 1*time.Second)
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if err != nil {
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log.Fatal(err)
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}
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responseVal, err := strconv.Atoi(string(resp.Data))
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if err != nil {
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log.Fatal(err)
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}
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fmt.Println(responseVal)
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//
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// Output: 4
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//
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}
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