updated docs against 4159

Signed-off-by: Nwusongqing <wusongqing@huawei.com>

en/application-dev/ability/fa-serviceability.md

@@ -8,8 +8,8 @@ A Service ability is used to run tasks in the background, such as playing music
 **Table 1** Service ability lifecycle callbacks
 |API|Description|
 |:------|:------|
-|onStart|Called to initialize a Service ability when the Service ability is being created. This callback is invoked only once in the entire lifecycle of a Service ability. The **Want** object passed to this callback must be null.|
-|onCommand|Called every time a Service ability is created on a client. You can calculate calling statistics and perform initialization operations in this callback.|
+|onStart|Called to initialize a Service ability being created. This callback is invoked only once in the entire lifecycle of a Service ability. The **Want** object passed to this callback must be null.|
+|onCommand|Called every time a Service ability is created on a client. You can collect calling statistics and perform initialization operations in this callback.|
 |onConnect|Called when another ability is connected to the Service ability.|
 |onDisconnect|Called when another ability is disconnected from the Service ability.|
 |onStop|Called when the Service ability is being destroyed. You should override this callback for your Service ability to clear its resources, such as threads and registered listeners.|
@@ -18,9 +18,7 @@ A Service ability is used to run tasks in the background, such as playing music
 
 ### Creating a Service Ability
 
-1. Create a child class of the **Ability** class and override the following Service ability-related lifecycle callbacks to implement your own logic for processing requests to interact with your Service ability:
-   
-   The following code snippet shows how to create a Service ability:
+1. Create a child class of the **Ability** class and override the following Service ability-related lifecycle callbacks to implement your own logic for processing interaction requests: 
    
    ```javascript
    export default {
@@ -32,6 +30,7 @@ A Service ability is used to run tasks in the background, such as playing music
        },
        onConnect(want) {
            console.log('ServiceAbility OnConnect');
+           return null;
        },
        onDisconnect(want) {
            console.log('ServiceAbility OnDisConnect');
@@ -41,7 +40,7 @@ A Service ability is used to run tasks in the background, such as playing music
        },
    }
    ```
-
+   
 2. Register a Service ability.
 
    You must declare your Service ability in the **config.json** file by setting its **type** attribute to **service**.
@@ -65,7 +64,7 @@ A Service ability is used to run tasks in the background, such as playing music
 
 
 
-### Starting a Service ability
+### Starting a Service Ability
 
 The **Ability** class provides the **startAbility()** API for you to start another Service ability by passing a **Want** object.
 
@@ -78,12 +77,12 @@ The following code snippet shows how to start a Service ability running on the l
 
 ```javascript
 import featureAbility from '@ohos.ability.featureAbility';
-let promise = await featureAbility.startAbility(
+let promise = featureAbility.startAbility(
     {
         want:
         {
-            bundleName: "com.jstest.serviceability",
-            abilityName: "com.jstest.serviceability.MainAbility",
+            bundleName: "com.jstest.service",
+            abilityName: "com.jstest.service.ServiceAbility",
         },
     }
 ); 
@@ -95,9 +94,9 @@ After the preceding code is executed, the **startAbility()** API is called to st
 
 
 
-### Stopping a Service ability
+### Stopping a Service Ability
 
-  Once created, the Service ability keeps running in the background. The system does not stop or destroy it unless memory resources must be reclaimed. You can call **terminateSelf()** on a Service ability to stop it.
+Once created, the Service ability keeps running in the background. The system does not stop or destroy it unless memory resources must be reclaimed. You can call **terminateSelf()** on a Service ability to stop it.
 
   
 
@@ -110,6 +109,8 @@ When calling **connectAbility()**, you should pass a **Want** object containing
 The following code snippet shows how to implement the callbacks:
 
 ```javascript
+import prompt from '@system.prompt'
+
 let mRemote;
 function onConnectCallback(element, remote){
     console.log('onConnectLocalService onConnectDone element: ' + element);
@@ -154,8 +155,8 @@ The following code snippet shows how to connect to a local Service ability:
 import featureAbility from '@ohos.ability.featureAbility';
 let connId = featureAbility.connectAbility(
     {
-        bundleName: "com.jstest.serviceability",
-        abilityName: "com.jstest.serviceability.MainAbility",
+        bundleName: "com.jstest.service",
+        abilityName: "com.jstest.service.ServiceAbility",
     },
     {
         onConnect: onConnectCallback,
@@ -165,7 +166,7 @@ let connId = featureAbility.connectAbility(
 );
 ```
 
-When a Service ability is connected, the **onConnect()** callback is invoked and returns an **IRemoteObject** defining the proxy used for communicating with the Service ability. OpenHarmony provides a default implementation of the **IRemoteObject** interface. You can inherit **rpc.RemoteObject** to implement your own class of **IRemoteObject**.
+When a Service ability is connected, the **onConnect()** callback is invoked and returns an **IRemoteObject** defining the proxy used for communicating with the Service ability. OpenHarmony provides a default implementation of the **IRemoteObject** interface. You can extend **rpc.RemoteObject** to implement your own class of **IRemoteObject**.
 
 The following code snippet shows how the Service ability instance returns itself to the calling ability:
 
@@ -213,16 +214,20 @@ export default {
 }
 ```
 
-### Connecting to a Remote Service Ability<a name="section126857614019"></a> (Applying only to System Applications)
->Note: The **getTrustedDeviceListSync** API of the **DeviceManager** class is open only to system applications. Therefore, remote Service ability startup applies only to system applications.
+### Connecting to a Remote Service Ability (Applying only to System Applications)
+>NOTE
+>
+>This feature applies only to system applications, since the **getTrustedDeviceListSync** API of the **DeviceManager** class is open only to system applications.
 
-If you need to connect a Service ability to a Page ability on another device or to a Service ability in another application on another device, you must first implement the **IAbilityConnection** interface for the connection. A Service ability allows other abilities on another device to connect to it through **connectAbility()**.
+If you need to connect a Service ability to a Page ability or another Service ability on a remote device, you must first implement the **IAbilityConnection** interface for the connection. A Service ability allows abilities on another device to connect to it through **connectAbility()**.
 
 When calling **connectAbility()**, you should pass a **Want** object containing information about the target Service ability and an **IAbilityConnection** object to the API. **IAbilityConnection** provides the following callbacks that you should implement: **onConnect()**, **onDisconnect()**, and **onFailed()**. The **onConnect()** callback is invoked when a Service ability is connected, **onDisconnect()** is invoked when a Service ability is unexpectedly disconnected, and **onFailed()** is invoked when a connection to a Service ability fails.
 
 The following code snippet shows how to implement the callbacks:
 
 ```ts
+import prompt from '@system.prompt'
+
 let mRemote;
 function onConnectCallback(element, remote){
     console.log('onConnectRemoteService onConnectDone element: ' + element);
@@ -264,7 +269,10 @@ The **Want** of the target Service ability must contain the remote **deviceId**,
 
 ```ts
 import deviceManager from '@ohos.distributedHardware.deviceManager';
+
+// For details about the implementation of dmClass, see the implementation in Distributed Demo in Samples.
 let dmClass;
+
 function getRemoteDeviceId() {
     if (typeof dmClass === 'object' && dmClass != null) {
         let list = dmClass.getTrustedDeviceListSync();
@@ -327,15 +335,12 @@ async function RequestPermission() {
   let context = featureAbility.getContext();
   context.requestPermissionsFromUser(requestPermissions, 1, (data)=>{
     console.info("data:" + JSON.stringify(data));
-    console.info("data requestCode:" + data.requestCode);
-    console.info("data permissions:" + data.permissions);
-    console.info("data authResults:" + data.authResults);
   });
   console.info('RequestPermission end');
 }
 ```
 
-When a Service ability is connected, the **onConnect()** callback is invoked and returns an **IRemoteObject** defining the proxy used for communicating with the Service ability. OpenHarmony provides a default implementation of the **IRemoteObject** interface. You can inherit **rpc.RemoteObject** to implement your own class of **IRemoteObject**.
+When a Service ability is connected, the **onConnect()** callback is invoked and returns an **IRemoteObject** defining the proxy used for communicating with the Service ability. OpenHarmony provides a default implementation of the **IRemoteObject** interface. You can extend **rpc.RemoteObject** to implement your own class of **IRemoteObject**.
 
 The following code snippet shows how the Service ability instance returns itself to the calling ability:
 
@@ -398,5 +403,5 @@ export default {
 ## Samples
 
 The following samples are provided to help you better understand how to develop a Service ability:
-- [`ServiceAbility`: Service Ability Creation and Use (eTS) (API8)](https://gitee.com/openharmony/app_samples/tree/master/ability/ServiceAbility)
-- [`DMS`: Distributed Demo (eTS) (API7)](https://gitee.com/openharmony/app_samples/tree/master/ability/DMS)
+- [`ServiceAbility`: Service Ability Creation and Use (eTS, API version 8)](https://gitee.com/openharmony/app_samples/tree/master/ability/ServiceAbility)
+- [`DMS`: Distributed Demo (eTS, API version 8)](https://gitee.com/openharmony/app_samples/tree/master/ability/DMS)