Updated on 2024-02-01 GMT+08:00

Querying a Topic

Function

This API is used to query a topic.

Calling Method

For details, see Calling APIs.

URI

GET /v2/{project_id}/instances/{instance_id}/topics/{topic}

Table 1 Path Parameters

Parameter

Mandatory

Type

Description

project_id

Yes

String

Project ID. For details, see Obtaining a Project ID.

instance_id

Yes

String

Instance ID.

topic

Yes

String

Topic name.

Request Parameters

None

Response Parameters

Status code: 200

Table 2 Response body parameters

Parameter

Type

Description

name

String

Topic name.

total_read_queue_num

Number

Total number of read queues.

total_write_queue_num

Number

Total number of write queues.

permission

String

Permissions.

brokers

Array of brokers objects

Associated brokers.

message_type

String

Message type (available only for RocketMQ 5.x instances).

Default: all

Table 3 brokers

Parameter

Type

Description

broker_name

String

Broker name.

read_queue_num

Number

Number of read queues.

write_queue_num

Number

Number of write queues.

Example Requests

Querying details about a specified topic

GET https://{endpoint}/v2/{project_id}/instances/{instance_id}/topics/{topic}

Example Responses

Status code: 200

Topic queried successfully.

{
  "total_read_queue_num" : 3,
  "total_write_queue_num" : 3,
  "permission" : "all",
  "brokers" : [ {
    "broker_name" : "broker-0",
    "read_queue_num" : 3,
    "write_queue_num" : 3
  } ],
  "message_type" : "NORMAL"
}

SDK Sample Code

The SDK sample code is as follows.

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package com.huaweicloud.sdk.test;

import com.huaweicloud.sdk.core.auth.ICredential;
import com.huaweicloud.sdk.core.auth.BasicCredentials;
import com.huaweicloud.sdk.core.exception.ConnectionException;
import com.huaweicloud.sdk.core.exception.RequestTimeoutException;
import com.huaweicloud.sdk.core.exception.ServiceResponseException;
import com.huaweicloud.sdk.rocketmq.v2.region.rocketmqRegion;
import com.huaweicloud.sdk.rocketmq.v2.*;
import com.huaweicloud.sdk.rocketmq.v2.model.*;


public class ShowOneTopicSolution {

    public static void main(String[] args) {
        // The AK and SK used for authentication are hard-coded or stored in plaintext, which has great security risks. It is recommended that the AK and SK be stored in ciphertext in configuration files or environment variables and decrypted during use to ensure security.
        // In this example, AK and SK are stored in environment variables for authentication. Before running this example, set environment variables CLOUD_SDK_AK and CLOUD_SDK_SK in the local environment
        String ak = System.getenv("CLOUD_SDK_AK");
        String sk = System.getenv("CLOUD_SDK_SK");

        ICredential auth = new BasicCredentials()
                .withAk(ak)
                .withSk(sk);

        rocketmqClient client = rocketmqClient.newBuilder()
                .withCredential(auth)
                .withRegion(rocketmqRegion.valueOf("<YOUR REGION>"))
                .build();
        ShowOneTopicRequest request = new ShowOneTopicRequest();
        try {
            ShowOneTopicResponse response = client.showOneTopic(request);
            System.out.println(response.toString());
        } catch (ConnectionException e) {
            e.printStackTrace();
        } catch (RequestTimeoutException e) {
            e.printStackTrace();
        } catch (ServiceResponseException e) {
            e.printStackTrace();
            System.out.println(e.getHttpStatusCode());
            System.out.println(e.getRequestId());
            System.out.println(e.getErrorCode());
            System.out.println(e.getErrorMsg());
        }
    }
}
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# coding: utf-8

from huaweicloudsdkcore.auth.credentials import BasicCredentials
from huaweicloudsdkrocketmq.v2.region.rocketmq_region import rocketmqRegion
from huaweicloudsdkcore.exceptions import exceptions
from huaweicloudsdkrocketmq.v2 import *

if __name__ == "__main__":
    # The AK and SK used for authentication are hard-coded or stored in plaintext, which has great security risks. It is recommended that the AK and SK be stored in ciphertext in configuration files or environment variables and decrypted during use to ensure security.
    # In this example, AK and SK are stored in environment variables for authentication. Before running this example, set environment variables CLOUD_SDK_AK and CLOUD_SDK_SK in the local environment
    ak = __import__('os').getenv("CLOUD_SDK_AK")
    sk = __import__('os').getenv("CLOUD_SDK_SK")

    credentials = BasicCredentials(ak, sk) \

    client = rocketmqClient.new_builder() \
        .with_credentials(credentials) \
        .with_region(rocketmqRegion.value_of("<YOUR REGION>")) \
        .build()

    try:
        request = ShowOneTopicRequest()
        response = client.show_one_topic(request)
        print(response)
    except exceptions.ClientRequestException as e:
        print(e.status_code)
        print(e.request_id)
        print(e.error_code)
        print(e.error_msg)
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package main

import (
	"fmt"
	"github.com/huaweicloud/huaweicloud-sdk-go-v3/core/auth/basic"
    rocketmq "github.com/huaweicloud/huaweicloud-sdk-go-v3/services/rocketmq/v2"
	"github.com/huaweicloud/huaweicloud-sdk-go-v3/services/rocketmq/v2/model"
    region "github.com/huaweicloud/huaweicloud-sdk-go-v3/services/rocketmq/v2/region"
)

func main() {
    // The AK and SK used for authentication are hard-coded or stored in plaintext, which has great security risks. It is recommended that the AK and SK be stored in ciphertext in configuration files or environment variables and decrypted during use to ensure security.
    // In this example, AK and SK are stored in environment variables for authentication. Before running this example, set environment variables CLOUD_SDK_AK and CLOUD_SDK_SK in the local environment
    ak := os.Getenv("CLOUD_SDK_AK")
    sk := os.Getenv("CLOUD_SDK_SK")

    auth := basic.NewCredentialsBuilder().
        WithAk(ak).
        WithSk(sk).
        Build()

    client := rocketmq.NewrocketmqClient(
        rocketmq.rocketmqClientBuilder().
            WithRegion(region.ValueOf("<YOUR REGION>")).
            WithCredential(auth).
            Build())

    request := &model.ShowOneTopicRequest{}
	response, err := client.ShowOneTopic(request)
	if err == nil {
        fmt.Printf("%+v\n", response)
    } else {
        fmt.Println(err)
    }
}

For SDK sample code of more programming languages, see the Sample Code tab in API Explorer. SDK sample code can be automatically generated.

Status Codes

Status Code

Description

200

Topic queried successfully.

Error Codes

See Error Codes.