我正在尝试使用Xmlserializer将数组列表保存到内部存储中的xml文件中。该应用程序扫描BLE，当按下一个停止按钮时，它应该从它检测到的BLE列表中保存一些参数。它运行完美，当我按下停止按钮时，它会停止扫描并在移动屏幕上显示已成功创建xml文件的Toast消息。但是，当我搜索xml文件时，它不会出现在任何地方，就好像它没有被创建一样。我不知道这个问题的原因。这是我实施的代码：
package com.example.newblescan;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import org.xmlpull.v1.XmlSerializer;
import com.example.newblescan.R;
import android.app.Activity;
import android.app.ListActivity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothManager;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.text.format.DateFormat;
import android.util.Xml;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ListView;
import android.widget.Toast;
import com.example.newblescan.adapter.BleDevicesAdapter;
/**
* Activity for scanning and displaying available Bluetooth LE devices.
*/
public class DeviceScanActivity extends ListActivity {
private static final int REQUEST_ENABLE_BT = 1;
private static final long SCAN_PERIOD = 100;
private BleDevicesAdapter leDeviceListAdapter;
private BluetoothAdapter bluetoothAdapter;
private Scanner scanner;
private Save save;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getActionBar().setTitle(R.string.title_devices);
// Use this check to determine whether BLE is supported on the device. Then you can
// selectively disable BLE-related features.
if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)) {
Toast.makeText(this, R.string.ble_not_supported, Toast.LENGTH_SHORT).show();
finish();
return;
}
// Initializes a Bluetooth adapter. For API level 18 and above, get a reference to
// BluetoothAdapter through BluetoothManager.
final BluetoothManager bluetoothManager =
(BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
bluetoothAdapter = bluetoothManager.getAdapter();
// Checks if Bluetooth is supported on the device.
if (bluetoothAdapter == null) {
Toast.makeText(this, R.string.error_bluetooth_not_supported, Toast.LENGTH_SHORT).show();
finish();
return;
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.gatt_scan, menu);
if (scanner == null || !scanner.isScanning()) {
menu.findItem(R.id.menu_stop).setVisible(false);
menu.findItem(R.id.menu_scan).setVisible(true);
menu.findItem(R.id.menu_refresh).setActionView(null);
} else {
menu.findItem(R.id.menu_stop).setVisible(true);
menu.findItem(R.id.menu_scan).setVisible(false);
menu.findItem(R.id.menu_refresh).setActionView(
R.layout.actionbar_indeterminate_progress);
}
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_scan:
leDeviceListAdapter.clear();
if (scanner == null) {
scanner = new Scanner(bluetoothAdapter, mLeScanCallback);
scanner.startScanning();
invalidateOptionsMenu();
}
break;
case R.id.menu_stop:
if (scanner != null) {
save = new Save(leDeviceListAdapter);
scanner.stopScanning();
try {
save.savedata();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
scanner = null;
invalidateOptionsMenu();
}
break;
}
return true;
}
@Override
protected void onResume() {
super.onResume();
// Ensures Bluetooth is enabled on the device. If Bluetooth is not currently enabled,
// fire an intent to display a dialog asking the user to grant permission to enable it.
if (!bluetoothAdapter.isEnabled()) {
final Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
return;
}
init();
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// User chose not to enable Bluetooth.
if (requestCode == REQUEST_ENABLE_BT) {
if (resultCode == Activity.RESULT_CANCELED) {
finish();
} else {
init();
}
}
super.onActivityResult(requestCode, resultCode, data);
}
@Override
protected void onPause() {
super.onPause();
if (scanner != null) {
scanner.stopScanning();
scanner = null;
}
}
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
final BluetoothDevice device = leDeviceListAdapter.getDevice(position);
if (device == null)
return;
//final Intent intent = new Intent(this, DeviceServicesActivity.class);
//intent.putExtra(DeviceServicesActivity.EXTRAS_DEVICE_NAME, device.getName());
//intent.putExtra(DeviceServicesActivity.EXTRAS_DEVICE_ADDRESS, device.getAddress());
//startActivity(intent);
}
private void init() {
if (leDeviceListAdapter == null) {
leDeviceListAdapter = new BleDevicesAdapter(getBaseContext());
setListAdapter(leDeviceListAdapter);
}
if (scanner == null) {
scanner = new Scanner(bluetoothAdapter, mLeScanCallback);
scanner.startScanning();
}
invalidateOptionsMenu();
}
// Device scan callback.
private BluetoothAdapter.LeScanCallback mLeScanCallback =
new BluetoothAdapter.LeScanCallback() {
@Override
public void onLeScan(final BluetoothDevice device, final int rssi, byte[] scanRecord) {
runOnUiThread(new Runnable() {
@Override
public void run() {
leDeviceListAdapter.addDevice(device, rssi);
leDeviceListAdapter.notifyDataSetChanged();
}
});
}
};
private static class Scanner extends Thread {
private final BluetoothAdapter bluetoothAdapter;
private final BluetoothAdapter.LeScanCallback mLeScanCallback;
private volatile boolean isScanning = false;
Scanner(BluetoothAdapter adapter, BluetoothAdapter.LeScanCallback callback) {
bluetoothAdapter = adapter;
mLeScanCallback = callback;
}
public boolean isScanning() {
return isScanning;
}
public void startScanning() {
synchronized (this) {
isScanning = true;
start();
}
}
public void stopScanning() {
synchronized (this) {
isScanning = false;
bluetoothAdapter.stopLeScan(mLeScanCallback);
}
}
@Override
public void run() {
try {
while (true) {
synchronized (this) {
if (!isScanning)
break;
bluetoothAdapter.startLeScan(mLeScanCallback);
}
sleep(SCAN_PERIOD);
synchronized (this) {
bluetoothAdapter.stopLeScan(mLeScanCallback);
}
}
} catch (InterruptedException ignore) {
} finally {
bluetoothAdapter.stopLeScan(mLeScanCallback);
}
}
}
public class Save {
/**
*
*/
private BleDevicesAdapter leDeviceListAdapter;
Save(BleDevicesAdapter BLEList) {
leDeviceListAdapter = BLEList;
}
public void savedata() throws FileNotFoundException{
String filename = "Dragon.txt";
//String date = (DateFormat.format("dd-MM-yyyy hh:mm:ss", new java.util.Date()).toString());
FileOutputStream fos = null;
int size = leDeviceListAdapter.getCount();
//Bundle extras = getIntent().getExtras();
//long timestamp = extras.getLong("currentTime");
try {
fos= openFileOutput(filename, Context.MODE_PRIVATE);
XmlSerializer serializer = Xml.newSerializer();
serializer.setOutput(fos, "UTF-8");
serializer.startDocument(null, Boolean.valueOf(true));
serializer.setFeature("http://xmlpull.org/v1/doc/features.html#indent-output", true);
serializer.startTag("", "root");
//serializer.startTag("", "timestamp");
//serializer.text(date);
//serializer.endTag("", "timestamp");
for(int j = 0 ; j < size ; j++)
{
BluetoothDevice devices = leDeviceListAdapter.getDevice(j);
//Integer signal = leDeviceListAdapter.getRSSI(j);
serializer.startTag("", "name");
serializer.text(devices.getName());
serializer.endTag("", "name");
serializer.startTag("", "address");
serializer.text(devices.getAddress());
serializer.endTag("", "address");
//serializer.startTag(null, "rssi");
//serializer.setProperty(null, signal);
//serializer.endTag(null, "rssi");
}
//ObjectOutputStream out = new ObjectOutputStream(fos);
//out.write((int) timestamp);
//out.writeObject(leDeviceListAdapter);
//out.close();
serializer.endDocument();
serializer.flush();
fos.close();
Toast.makeText(DeviceScanActivity.this, R.string.list_saved, Toast.LENGTH_SHORT).show();
} catch (FileNotFoundException e){
e.printStackTrace();
} catch (IOException e){
e.printStackTrace();
}
}
}
}
在Save类中，我实现了saveata方法，将列表保存到xml文件中。
有谁知道这是什么问题？求助!!!!
答案 0 :(得分：0)
openFileOutput将其放在/ data / data / your_packagename / files目录中。此目录只能由root和您的应用程序读取 - 如果不为您的设备生根，您将无法在任何其他程序中找到该文件。除非您具有root访问权限，否则您将无法在文件资源管理器中找到它。如果您希望能够看到该文件，则需要将其写入世界可访问的地方，例如SD卡。