update doc

Signed-off-by: Nshawn_he <shawn.he@huawei.com>

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

 # Data Request
 
->![](public_sys-resources/icon-note.gif) **NOTE**
+This module provides the HTTP data request capability. An application can initiate a data request over HTTP. Common HTTP methods include **GET**, **POST**, **OPTIONS**, **HEAD**, **PUT**, **DELETE**, **TRACE**, and **CONNECT**.
+
+>**NOTE**
 >
 >The initial APIs of this module are supported since API version 6. Newly added APIs will be marked with a superscript to indicate their earliest API version.
 >
@@ -18,17 +20,17 @@ import http from '@ohos.net.http';
 
 // Each HttpRequest corresponds to an HttpRequestTask object and cannot be reused.
 let httpRequest = http.createHttp();
-// Subscribe to the HTTP response header, which is returned earlier than HttpRequest. You can subscribe to HTTP Response Header events based on service requirements.
-// on('headerReceive', AsyncCallback) will be replaced by on('headersReceive', Callback) in API version 8. 8+
+// Subscribe to the HTTP response header, which is returned earlier than httpRequest. Whether to subscribe to the HTTP response header is up to your decision.
+// on('headerReceive', AsyncCallback) is replaced by on('headersReceive', Callback) since API version 8.
 httpRequest.on('headersReceive', (header) => {
     console.info('header: ' + JSON.stringify(header));
 });
 httpRequest.request(
-    // Set the URL of the HTTP request. You need to define the URL. Set the parameters of the request in extraData.
+    // Customize EXAMPLE_URL on your own. It is up to you whether to add parameters to the URL.
     "EXAMPLE_URL",
     {
         method: http.RequestMethod.POST, // Optional. The default value is http.RequestMethod.GET.
-        // You can add the header field based on service requirements.
+        // You can add header fields based on service requirements.
         header: {
             'Content-Type': 'application/json'
         },
@@ -48,7 +50,7 @@ httpRequest.request(
             console.info('cookies:' + data.cookies); // 8+
         } else {
             console.info('error:' + JSON.stringify(err));
-            // Call the destroy() method to release resources after the call is complete.
+            // Call the destroy() method to release resources after HttpRequest is complete.
             httpRequest.destroy();
         }
     }
@@ -79,7 +81,7 @@ let httpRequest = http.createHttp();
 
 ## HttpRequest
 
-Defines an **HttpRequest** object. Before invoking HttpRequest APIs, you must call [createHttp\(\)](#httpcreatehttp) to create an **HttpRequestTask** object.
+HTTP request task. Before invoking APIs provided by **HttpRequest**, you must call [createHttp\(\)](#httpcreatehttp) to create an **HttpRequestTask** object.
 
 ### request
 
@@ -94,7 +96,7 @@ Initiates an HTTP request to a given URL. This API uses an asynchronous callback
 **Parameters**
 
 | Name  | Type                                          | Mandatory| Description                   |
-| -------- | ------------------------------------------------------- | ---- | ----------------------- |
+| -------- | ---------------------------------------------- | ---- | ----------------------- |
 | url      | string                                         | Yes  | URL for initiating an HTTP request.|
 | callback | AsyncCallback\<[HttpResponse](#httpresponse)\> | Yes  | Callback used to return the result.             |
 
@@ -170,14 +172,14 @@ Initiates an HTTP request to a given URL. This API uses a promise to return the
 **Parameters**
 
 | Name | Type              | Mandatory| Description                                           |
-| ------- | ------------------ | ---- | -------------------------------------------------- |
+| ------- | ------------------ | ---- | ----------------------------------------------- |
 | url     | string             | Yes  | URL for initiating an HTTP request.                        |
 | options | HttpRequestOptions | Yes  | Request options. For details, see [HttpRequestOptions](#httprequestoptions).|
 
 **Return value**
 
 | Type                                  | Description                             |
-| :-------------------- | :-------------------------------- |
+| :------------------------------------- | :-------------------------------- |
 | Promise<[HttpResponse](#httpresponse)> | Promise used to return the result.|
 
 
@@ -225,8 +227,7 @@ on\(type: 'headerReceive', callback: AsyncCallback<Object\>\): void
 Registers an observer for HTTP Response Header events.
 
 >![](public_sys-resources/icon-note.gif) **NOTE**
->
-> This API has been deprecated. You are advised to use [on\('headersReceive'\)<sup>8+</sup>](#onheadersreceive8) instead.
+>This API has been deprecated. You are advised to use [on\('headersReceive'\)<sup>8+</sup>](#onheadersreceive8) instead.
 
 **System capability**: SystemCapability.Communication.NetStack
 
@@ -308,7 +309,6 @@ off\(type: 'headersReceive', callback?: Callback<Object\>\): void
 Unregisters the observer for HTTP Response Header events.
 
 >![](public_sys-resources/icon-note.gif) **NOTE**
->
 >You can pass the callback of the **on** function if you want to cancel listening for a certain type of event. If you do not pass the callback, you will cancel listening for all events.
 
 **System capability**: SystemCapability.Communication.NetStack
@@ -356,10 +356,10 @@ Specifies the type and value range of the optional parameters in the HTTP reques
 **System capability**: SystemCapability.Communication.NetStack
 
 | Name        | Type                                         | Mandatory| Description                                                        |
-| -------------- | ------------------------------------ | ---- | ---------------------------------------------------------- |
+| -------------- | --------------------------------------------- | ---- | ------------------------------------------------------------ |
 | method         | [RequestMethod](#requestmethod)               | No  | Request method.                                                  |
 | extraData      | string \| Object  \| ArrayBuffer<sup>8+</sup> | No  | Additional data of the request.<br>- If the HTTP request uses a POST or PUT method, this parameter serves as the content of the HTTP request.<br>- If the HTTP request uses a GET, OPTIONS, DELETE, TRACE, or CONNECT method, this parameter is a supplement to the HTTP request parameters and will be added to the URL when the request is sent.<sup>8+</sup><br>- To pass in a string object, you first need to encode the object on your own.<sup>8+</sup> |
-| header         | Object                               | No  | HTTP request header. The default value is {'Content-Type': 'application/json'}.|
+| header         | Object                                        | No  | HTTP request header. The default value is **{'Content-Type': 'application/json'}**.  |
 | readTimeout    | number                                        | No  | Read timeout duration. The default value is **60000**, in ms.             |
 | connectTimeout | number                                        | No  | Connection timeout interval. The default value is **60000**, in ms.             |
 
@@ -388,7 +388,7 @@ Enumerates the response codes for an HTTP request.
 
 | Name             | Value  | Description                                                        |
 | ----------------- | ---- | ------------------------------------------------------------ |
-| OK                | 200  | "OK." The request has been processed successfully. This return code is generally used for GET and POST requests.                           |
+| OK                | 200  | Request succeeded. The request has been processed successfully. This return code is generally used for GET and POST requests.                           |
 | CREATED           | 201  | "Created." The request has been successfully sent and a new resource is created.                          |
 | ACCEPTED          | 202  | "Accepted." The request has been accepted, but the processing has not been completed.                        |
 | NOT_AUTHORITATIVE | 203  | "Non-Authoritative Information." The request is successful.                                      |
@@ -433,6 +433,17 @@ Defines the response to an HTTP request.
 | Name              | Type                                        | Mandatory| Description                                                        |
 | -------------------- | -------------------------------------------- | ---- | ------------------------------------------------------------ |
 | result               | string \| Object \| ArrayBuffer<sup>8+</sup> | Yes  | Response content returned based on **Content-type** in the response header:<br>- application/json: a string in JSON format. If you want to use specific content in the response, you need to implement parsing of that content.<br>- application/octet-stream: ArrayBuffer<br>- Others: string|
-| responseCode         | [ResponseCode](#responsecode) \| number      | Yes  | Result code for an HTTP request. If the callback function is successfully executed, a result code defined in [ResponseCode](#responsecode) will be returned. Otherwise, an error code will be returned in the **err** field in **AsyncCallback**. The error code can be one of the following:<br>- 200: common error<br>- 202: parameter error<br>- 300: I/O error|
+| responseCode         | [ResponseCode](#responsecode) \| number      | Yes  | Result code for an HTTP request. If the callback function is successfully executed, a result code defined in [ResponseCode](#responsecode) will be returned. Otherwise, an error code will be returned in the **err** field in **AsyncCallback**. For details, see [Error Codes](#error-codes).|
 | header               | Object                                       | Yes  | Response header. The return value is a string in JSON format. If you want to use specific content in the response, you need to implement parsing of that content. Common fields and parsing methods are as follows:<br>- Content-Type: header['Content-Type'];<br>- Status-Line: header['Status-Line'];<br>- Date: header.Date/header['Date'];<br>- Server: header.Server/header['Server'];|
 | cookies<sup>8+</sup> | Array\<string\>                              | Yes  | Cookies returned by the server.                                      |
+
+## Error Codes
+
+| Error Code| Description                                                        |
+| ------ | ------------------------------------------------------------ |
+| -1     | Incorrect parameters.                                                  |
+| 3      | Incorrect URL format.                                               |
+| 4      | Built-in request function, protocol, or option not found during build.                  |
+| 5      | Unable to resolve the proxy.                                              |
+| 6      | Unable to resolve the host.                                              |
+| 7      | Unable to connect to the proxy or host.                                        |