Use SAP OData Offline library to achieve offline mode of Android applications

Open Android Studio, add the following dependencies to your project build.gradle, and import the SAP OData Offline library:

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

Click Sync Now:

Create a new Java file: sapServicemanager.java

The following import is used:

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;

// Comment out OfflineODataProvider to OfflineODataProvider
//private OnlineODataProvider provider;
private OfflineODataProvider provider;
private static finalString TAG = SAPServiceManager.class.getName(); OData offiline datastore setuppublic 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 OfflineODataProvider
            AndroidSystem.setContext(context);
            //commonly set parameters include setStoreEncryptionKey, setStoreName, setStorePath
            OfflineODataParameters 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 store
            provider.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(a) {
    //send the local changes to the back end OData service
    Log.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(a) {
    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;
}
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New LogonActivity. Java, call before implementation of sapServiceManager. OpenODataStore:

If you run the app for the first time, you will find the initialization log of offline OData Store:

Now you can test offline mode by turning on airplane mode on your mobile device:

Select a customer stored on OData Offline Store and click the Edit button:

Modify the city field:

Close the application, close the flight mode of the device, and then start the application. In Logcat, you can observe that the data modified in offline mode has been automatically synchronized to the background Online Store:

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