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本篇文章给大家分享的是有关如何使用SAP OData offline库实现Android应用的离线模式，小编觉得挺实用的，因此分享给大家学习，希望大家阅读完这篇文章后可以有所收获，话不多说，跟着小编一起来看看吧。
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打开Android studio，在工程的build.gradle里加入下面的依赖，导入SAP OData offline库：
点击Sync now：
新建一个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; // 将OfflineODataProvider注释掉，改为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 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() {
//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() {
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，调用之前实现的sapServiceManager.openODataStore:
第一次运行应用，会发现offline OData store的初始化日志：
现在可以测试离线模式了，打开移动设备的飞行模式：
选择存储于OData offline store上的某个客户，点击编辑按钮：
修改city字段：
关闭该应用，关闭设备的飞行模式，再启动该应用，在logcat里能观察到之前处于离线模式修改的数据已经自动同步到了后台online store里：
以上就是如何使用SAP OData offline库实现Android应用的离线模式，小编相信有部分知识点可能是我们日常工作会见到或用到的。希望你能通过这篇文章学到更多知识。更多详情敬请关注创新互联行业资讯频道。