ReceiveLPMessagev2
ReceiveLPMessagev2.go
This example gets the most recent message from a long-polling Amazon SQS queue.
go run ReceiveLPMessagev2.go -q QUEUE-NAME
- QUEUE-NAME is the name of the queue from which the message is retrieved.
The unit test accepts a similar value in config.json.
Source code
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX - License - Identifier: Apache - 2.0
package main
import (
"context"
"flag"
"fmt"
"github.com/aws/aws-sdk-go-v2/config"
"github.com/aws/aws-sdk-go-v2/service/sqs"
"github.com/aws/aws-sdk-go-v2/service/sqs/types"
)
// SQSGetLPMsgAPI defines the interface for the GetQueueUrl and ReceiveMessage functions.
// We use this interface to test the functions using a mocked service.
type SQSGetLPMsgAPI interface {
GetQueueUrl(ctx context.Context,
params *sqs.GetQueueUrlInput,
optFns ...func(*sqs.Options)) (*sqs.GetQueueUrlOutput, error)
ReceiveMessage(ctx context.Context,
params *sqs.ReceiveMessageInput,
optFns ...func(*sqs.Options)) (*sqs.ReceiveMessageOutput, error)
}
// GetQueueURL gets the URL of an Amazon SQS queue.
// Inputs:
// c is the context of the method call, which includes the AWS Region.
// api is the interface that defines the method call.
// input defines the input arguments to the service call.
// Output:
// If success, a GetQueueUrlOutput object containing the result of the service call and nil.
// Otherwise, nil and an error from the call to GetQueueUrl.
func GetQueueURL(c context.Context, api SQSGetLPMsgAPI, input *sqs.GetQueueUrlInput) (*sqs.GetQueueUrlOutput, error) {
return api.GetQueueUrl(c, input)
}
// GetLPMessages gets the messages from an Amazon SQS long polling queue.
// Inputs:
// c is the context of the method call, which includes the AWS Region.
// api is the interface that defines the method call.
// input defines the input arguments to the service call.
// Output:
// If success, a ReceiveMessageOutput object containing the result of the service call and nil.
// Otherwise, nil and an error from the call to ReceiveMessage.
func GetLPMessages(c context.Context, api SQSGetLPMsgAPI, input *sqs.ReceiveMessageInput) (*sqs.ReceiveMessageOutput, error) {
return api.ReceiveMessage(c, input)
}
func main() {
queue := flag.String("q", "", "The name of the queue")
waitTime := flag.Int("w", 10, "How long the queue waits for messages")
flag.Parse()
if *queue == "" {
fmt.Println("You must supply a queue name (-q QUEUE")
return
}
if *waitTime < 0 {
*waitTime = 0
}
if *waitTime > 20 {
*waitTime = 20
}
cfg, err := config.LoadDefaultConfig(context.TODO())
if err != nil {
panic("configuration error, " + err.Error())
}
client := sqs.NewFromConfig(cfg)
qInput := &sqs.GetQueueUrlInput{
QueueName: queue,
}
result, err := GetQueueURL(context.TODO(), client, qInput)
if err != nil {
fmt.Println("Got an error getting the queue URL:")
fmt.Println(err)
return
}
queueURL := result.QueueUrl
mInput := &sqs.ReceiveMessageInput{
QueueUrl: queueURL,
AttributeNames: []types.QueueAttributeName{
"SentTimestamp",
},
MaxNumberOfMessages: 1,
MessageAttributeNames: []string{
"All",
},
WaitTimeSeconds: int32(*waitTime),
}
resp, err := GetLPMessages(context.TODO(), client, mInput)
if err != nil {
fmt.Println("Got an error receiving messages:")
fmt.Println(err)
return
}
fmt.Println("Message IDs:")
for _, msg := range resp.Messages {
fmt.Println(" " + *msg.MessageId)
}
}
See the complete example in GitHub.
Last modified January 15, 2021: Code Example Highlighting, Vairous Documentation Fixes (#1045) (495b900)