打開Android studio，在工程的build.gradle里加入下面的依賴，導入SAP OData offline庫：

implementation group:‘com.sap.cloud.android’, name:‘offline-odata’, version: sdkVersion

點擊Sync now：

新建一個java文件：SAPServiceManager.java

使用的import如下：

import android.content.Context; import android.util.Log; import android.widget.Toast; import com.sap.cloud.mobile.odata.core.AndroidSystem; import com.sap.cloud.mobile.odata.offline.OfflineODataDefiningQuery; import com.sap.cloud.mobile.odata.offline.OfflineODataException; import com.sap.cloud.mobile.odata.offline.OfflineODataParameters; import com.sap.cloud.mobile.odata.offline.OfflineODataProvider; import java.net.MalformedURLException; import java.net.URL;// 將OfflineODataProvider注釋掉，改為OfflineODataProvider //private OnlineODataProvider provider; private OfflineODataProvider provider; private static final String TAG = SAPServiceManager.class.getName();OData offiline datastore的setup方法：public void openODataStore(Action0 callback, Context context) {setupOfflineOData(callback, context); }private void setupOfflineOData(Action0 callback, Context context) {try {if (configurationData.loadData()) {Toast.makeText(context, "Opening the offline store which may take a few moments the first time it is opened.", Toast.LENGTH_LONG).show();//Initialize application context for use by OfflineODataProviderAndroidSystem.setContext(context);//commonly set parameters include setStoreEncryptionKey, setStoreName, setStorePathOfflineODataParameters offParam = new OfflineODataParameters();String serviceUrl = configurationData.getServiceUrl();URL url = new URL(serviceUrl + CONNECTION_ID_ESPMCONTAINER);provider = new OfflineODataProvider(url, offParam, ClientProvider.get());//Specifies which entities we wish to include in the offline storeprovider.addDefiningQuery(new OfflineODataDefiningQuery("Customers", "Customers", false));}} catch (MalformedURLException e) {e.printStackTrace();} catch (OfflineODataException e) {e.printStackTrace();}//opens the offline store. This can take a minute or so the first time it is called as it is created and populated.Log.d(TAG, "About to call open on the offline store.");provider.open(() -> {Log.d(TAG, "Offline store opened.");eSPMContainer = new ESPMContainer(provider);callback.call();syncOfflineData(); //TODO could be triggered via a menu action}, (OfflineODataException offlineODataException) -> {Log.d(TAG, "Offline store did not open.", offlineODataException);}); }public void syncOfflineData() {//send the local changes to the back end OData serviceLog.d(TAG, "About to call provider.upload.");provider.upload(() -> {Log.d(TAG, "Successfully uploaded the changed data.");//get changes from the back end OData service.provider.download(() -> {Log.d(TAG, "Successfully downloaded the changed data.");}, (error) -> {Log.d(TAG, "Failed when downloading the changed data with error: " + error.getMessage());});}, (error) -> {Log.d(TAG, "Failed when uploading the changed data with error: " + error.getMessage());}); }public String getServiceRoot() {if (configurationData.loadData()) {String serviceUrl = configurationData.getServiceUrl();if (serviceRoot == null) {serviceRoot = serviceUrl + "/" + CONNECTION_ID_ESPMCONTAINER;}}else {throw new IllegalStateException("SAPService manager configurationData.loadData() failed.");}return serviceRoot; }

新建LogonActivity.java，調用之前實現的sapServiceManager.openODataStore:

第一次運行應用，會發現offline OData store的初始化日志：

現在可以測試離線模式了，打開移動設備的飛行模式：

選擇存儲于OData offline store上的某個客戶，點擊編輯按鈕：

修改city字段：

關閉該應用，關閉設備的飛行模式，再啟動該應用，在logcat里能觀察到之前處于離線模式修改的數據已經自動同步到了后臺online store里：

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