update docs

Signed-off-by: NAnnie_wang <annie.wangli@huawei.com>

en/application-dev/reference/apis/Readme-EN.md

@@ -124,6 +124,7 @@
   - [@ohos.statfs](js-apis-statfs.md)
   - [@ohos.storageStatistics](js-apis-storage-statistics.md)
   - [@ohos.volumeManager](js-apis-volumemanager.md)
+  - [@ohos.securityLabel](js-apis-securityLabel.md)
 
 - Telephony Service
 

en/application-dev/reference/apis/js-apis-securityLabel.md

+# Security Label
+
+> **NOTE**<br/>
+> The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.
+
+This module provides functions related to file security levels. It provides JS APIs to obtain and set file security levels.
+
+## Modules to Import
+
+```js
+import securityLabel from '@ohos.securityLabel';
+```
+
+## Usage
+
+Before using the APIs provided by this module to perform operations on a file or directory, obtain the path of the application sandbox. For details, see [getOrCreateLocalDir of the Context module](js-apis-Context.md).
+
+Application sandbox path of a file or directory = Application directory + File name or directory name
+
+For example, if the application directory obtained by using **getOrCreateLocalDir** is **dir** and the file name is **xxx.txt**, the application sandbox path of the file is as follows:
+
+```js
+let path = dir + "/xxx.txt";
+```
+
+The file descriptor is as follows:
+
+```js
+let fd = fileio.openSync(path, 0o102, 0o666);
+```
+
+## securityLabel.setSecurityLabel
+
+setSecurityLabel(path:string, dataLevel:string):Promise&lt;void&gt;
+
+Sets the security label for a file in asynchronous mode. This API uses a promise to return the result.
+
+**System capability**: SystemCapability.FileManagement.File.DistributedFile
+
+**Parameters**
+
+| Name   | Type  | Mandatory| Description                                        |
+| --------- | ------ | ---- | -------------------------------------------- |
+| path      | string | Yes  | File path.                                    |
+| dataLevel | string | Yes  | File security level, which can be **s0**, **s1**, **s2**, **s3**, or **s4**.|
+
+**Return value**
+
+  | Type               | Description            |
+  | ------------------- | ---------------- |
+  | Promise&lt;void&gt; | Promise used to return the result. An empty value will be returned.|
+
+**Example**
+
+  ```js
+  securityLabel.setSecurityLabel(path, dataLevel).then(function(){
+      console.info("setSecurityLabel successfully");
+  }).catch(function(error){
+      console.info("setSecurityLabel failed with error:" + error);
+  });
+  ```
+
+## securityLabel.setSecurityLabel
+
+setSecurityLabel(path:string, dataLevel:string, callback: AsyncCallback&lt;void&gt;):void
+
+Sets the security label for a file in asynchronous mode. This API uses an asynchronous callback to return the result.
+
+**System capability**: SystemCapability.FileManagement.File.DistributedFile
+
+**Parameters**
+
+| Name   | Type                     | Mandatory| Description                                        |
+| --------- | ------------------------- | ---- | -------------------------------------------- |
+| path      | string                    | Yes  | File path.                                    |
+| dataLevel | string                    | Yes  | File security level, which can be **s0**, **s1**, **s2**, **s3**, or **s4**.|
+| callback  | AsyncCallback&lt;void&gt; | Yes  | Callback used to return the result.                  |
+
+**Example**
+
+  ```js
+  securityLabel.setSecurityLabel(path, dataLevel, function(error){
+      console.info("setSecurityLabel:" + JSON.stringify(error));
+  });
+  ```
+## securityLabel.setSecurityLabelSync
+
+setSecurityLabelSync(path:string, dataLevel:string):void
+
+Sets the security label for a file in synchronous mode.
+
+**System capability**: SystemCapability.FileManagement.File.DistributedFile
+
+**Parameters**
+
+| Name   | Type  | Mandatory| Description                                        |
+| --------- | ------ | ---- | -------------------------------------------- |
+| path      | string | Yes  | File path.                                    |
+| dataLevel | string | Yes  | File security level, which can be **s0**, **s1**, **s2**, **s3**, or **s4**.|
+
+**Example**
+
+```js
+securityLabel.setSecurityLabelSync(path, dataLevel);
+```
+
+## securityLabel.getSecurityLabel
+
+getSecurityLabel(path:string):Promise&lt;string&gt;
+
+Obtains the security label of a file in asynchronous mode. This API uses a promise to return the result.
+
+**System capability**: SystemCapability.FileManagement.File.DistributedFile
+
+**Parameters**
+
+  | Name| Type  | Mandatory| Description    |
+  | ------ | ------ | ---- | -------- |
+  | path   | string | Yes  | File path.|
+
+**Return value**
+
+  | Type                 | Description        |
+  | --------------------- | ------------ |
+  | Promise&lt;string&gt; | Promise used to return the security label obtained.|
+
+**Example**
+
+  ```js
+  securityLabel.getSecurityLabel(path).then(function(dataLevel){
+      console.log("getSecurityLabel successfully:" + dataLevel);
+  }).catch(function(error){
+      console.log("getSecurityLabel failed with error:" + error);
+  });
+  ```
+
+## securityLabel.getSecurityLabel
+
+getSecurityLabel(path:string, callback:AsyncCallback&lt;string&gt;): void
+
+Obtains the security label of a file in asynchronous mode. This API uses an asynchronous callback to return the result.
+
+**System capability**: SystemCapability.FileManagement.File.DistributedFile
+
+**Parameters**
+
+  | Name  | Type                       | Mandatory| Description                      |
+  | -------- | --------------------------- | ---- | -------------------------- |
+  | path     | string                      | Yes  | File path.                  |
+  | callback | AsyncCallback&lt;string&gt; | Yes  | Callback used to return the security label obtained.|
+
+**Example**
+
+  ```js
+  securityLabel.getSecurityLabel(function(error, dataLevel){
+      console.log("getSecurityLabel successfully:" + dataLevel);
+  });
+  ```
+## securityLabel.getSecurityLabelSync
+
+getSecurityLabelSync(path:string):string
+
+Obtains the security label of a file in synchronous mode.
+
+**System capability**: SystemCapability.FileManagement.File.DistributedFile
+
+**Parameters**
+
+| Name| Type  | Mandatory| Description    |
+| ------ | ------ | ---- | -------- |
+| path   | string | Yes  | File path.|
+
+**Return value**
+
+| Type  | Description        |
+| ------ | ------------ |
+| string | Security label obtained.|
+
+**Example**
+
+```js
+let result = securityLabel.getSecurityLabelSync(path);
+console.log("getSecurityLabel successfully:" + result);
+```