# 查询告警通知主题 - ShowTopics
#### 功能介绍
查询告警通知主题，返回默认主题、已确认主题数量及列表
#### 调用方法
请参见[如何调用API](https://support.huaweicloud.com/api-dsc/dsc_02_0008.html)。
#### 授权信息
账号具备所有API的调用权限，如果使用账号下的IAM用户调用当前API，该IAM用户需具备调用API所需的权限。
- 如果使用角色与策略授权，具体权限要求请参见[权限和授权项](https://support.huaweicloud.com/api-dsc/dsc_02_0031.html)。
- 如果使用身份策略授权，当前API调用无需身份策略权限。
 
#### URI
GET /v1/{project_id}/sdg/smn/topics
表1路径参数 
| 参数         | 是否必选 | 参数类型   | 描述   |
|:---|:---|:---|:---|
| project_id | 是    | String | 项目ID |
   
表2Query参数 
| 参数     | 是否必选 | 参数类型    | 描述   |
|:---|:---|:---|:---|
| offset | 否    | Integer | 页码   |
| limit  | 否    | Integer | 分页大小 |
   
#### 请求参数
无
#### 响应参数
**状态码：200**
表3响应Body参数 
| 参数                | 参数类型                                                          | 描述                     |
|:---|:---|:---|
| id                | String                                                        | DSC告警主题ID（非消息通知服务主题ID） |
| default_topic_urn | String                                                        | 默认消息通知主题的唯一资源标识符       |
| topic_count       | Integer                                                       | 已确认的消息通知主题数量           |
| topics            | Array of [TopicBean] objects | 已确认的消息通知主题列表           |
   
 表4TopicBean 
| 参数        | 参数类型   | 描述             |
|:---|:---|:---|
| name      | String | 消息通知主题名称       |
| topic_urn | String | 消息通知主题的唯一资源标识符 |
   
**状态码：400**
表5响应Body参数 
| 参数         | 参数类型   | 描述   |
|:---|:---|:---|
| error_code | String | 错误码  |
| error_msg  | String | 错误信息 |
   
#### 请求示例
查询告警通知主题
```
GET /v1/{project_id}/sdg/smn/topics
```
#### 响应示例
**状态码：200**
请求成功
```
{
  "id" : "xxxxxx",
  "default_topic_urn" : "xxxxxx",
  "topic_count" : 1,
  "topics" : [ {
    "name" : "xxxxxx",
    "topic_urn" : "xxxxxx"
  } ]
}
```
**状态码：400**
无效请求
```
{
  "error_code" : "dsc.40000011",
  "error_msg" : "Invalid parameter"
}
```
#### SDK代码示例
SDK代码示例如下。
#### Java
```
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.dsc.v1.region.DscRegion;
import com.huaweicloud.sdk.dsc.v1.*;
import com.huaweicloud.sdk.dsc.v1.model.*;
public class ShowTopicsSolution {
    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");
        String projectId = "{project_id}";
        ICredential auth = new BasicCredentials()
                .withProjectId(projectId)
                .withAk(ak)
                .withSk(sk);
        DscClient client = DscClient.newBuilder()
                .withCredential(auth)
                .withRegion(DscRegion.valueOf("<YOUR REGION>"))
                .build();
        ShowTopicsRequest request = new ShowTopicsRequest();
        try {
            ShowTopicsResponse response = client.showTopics(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());
        }
    }
}
```
#### Python
```
# coding: utf-8
import os
from huaweicloudsdkcore.auth.credentials import BasicCredentials
from huaweicloudsdkdsc.v1.region.dsc_region import DscRegion
from huaweicloudsdkcore.exceptions import exceptions
from huaweicloudsdkdsc.v1 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 = os.environ["CLOUD_SDK_AK"]
    sk = os.environ["CLOUD_SDK_SK"]
    projectId = "{project_id}"
    credentials = BasicCredentials(ak, sk, projectId)
    client = DscClient.new_builder() \
        .with_credentials(credentials) \
        .with_region(DscRegion.value_of("<YOUR REGION>")) \
        .build()
    try:
        request = ShowTopicsRequest()
        response = client.show_topics(request)
        print(response)
    except exceptions.ClientRequestException as e:
        print(e.status_code)
        print(e.request_id)
        print(e.error_code)
        print(e.error_msg)
```
#### Go
```
package main
import (
"fmt"
"github.com/huaweicloud/huaweicloud-sdk-go-v3/core/auth/basic"
    dsc "github.com/huaweicloud/huaweicloud-sdk-go-v3/services/dsc/v1"
"github.com/huaweicloud/huaweicloud-sdk-go-v3/services/dsc/v1/model"
    region "github.com/huaweicloud/huaweicloud-sdk-go-v3/services/dsc/v1/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")
    projectId := "{project_id}"
    auth, err := basic.NewCredentialsBuilder().
        WithAk(ak).
        WithSk(sk).
        WithProjectId(projectId).
        SafeBuild()
    if err != nil {
        fmt.Println(err)
        return
    }
    hcClient, err := dsc.DscClientBuilder().
         WithRegion(region.ValueOf("<YOUR REGION>")).
         WithCredential(auth).
         SafeBuild()
    if err != nil {
        fmt.Println(err)
        return
    }
    client := dsc.NewDscClient(hcClient)
    request := &model.ShowTopicsRequest{}
response, err := client.ShowTopics(request)
if err == nil {
        fmt.Printf("%+v\n", response)
    } else {
        fmt.Println(err)
    }
}
```
#### 更多
更多编程语言的SDK代码示例，请参见[API Explorer](https://console.huaweicloud.com/apiexplorer/#/openapi/DSC/sdk?api=ShowTopics)的代码示例页签，可生成自动对应的SDK代码示例。
#### 状态码
| 状态码 | 描述   |
|:---|:---|
| 200 | 请求成功 |
| 400 | 无效请求 |
   
#### 错误码
请参见[错误码](https://support.huaweicloud.com/api-dsc/ErrorCode.html)。