用于BLE扫描回调的类加载期间NoClassDefFoundError
用于BLE扫描回调的类加载期间NoClassDefFoundError
提问于 2014-04-28 11:47:50
当我的类加载时，我一直在获取NoClassDefFoundError。
代码摘自BluetoothLeGatt项目-
http://developer.android.com/samples/BluetoothLeGatt/project.html
我的代码：
// Device scan callback.
private BluetoothAdapter.LeScanCallback mLeScanCallback =
new BluetoothAdapter.LeScanCallback() { //java.lang.NoClassDefFoundError...
@Override
public void onLeScan(final BluetoothDevice device,
final int rssi, final byte[] scanRecord) {
runOnUiThread(new Runnable() {
@Override
public void run() {
String msg= device.getAddress();
Log.d(TAG,msg);
addItems(msg);
}
});
}
};有人建议这个错误是因为我的设备不支持BLE，但是我想消除任何设备的这个错误。因此，如果它不支持BLE特性，那么只需跳过这个错误，否则继续调用这个BluetoothAdapter.LeScanCallback。
注：
有关更多的说明，请参见this我的上一篇文章。
将BLE特性检查作为onCreate()的第一行并不能阻止崩溃--
@Override
public void onCreate(Bundle savedInstanceState) {
if (!bleCheck()) {
Toast.makeText(getApplicationContext(), R.string.ble_not_supported,
Toast.LENGTH_SHORT).show();
finish();
}
//Rest of the code
//Call to BLE Scan on button click that causes error..
}
private boolean bleCheck() {
boolean result = false;
if (getPackageManager().
hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)){
result = true;
}
return result;
}回答 1
Stack Overflow用户
回答已采纳
发布于 2014-04-28 12:07:28
由于BluetoothAdapter.LeScanCallback是在API 18；Source中添加的，所以这段代码也需要一个API级别检查。下面是我所做的工作，不是将回调声明为私有，而是在以下条件下进行的：
boolean apiJBorAbove = android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.JELLY_BEAN_MR2 ? true
: false;
boolean isBleAvailable = getPackageManager().hasSystemFeature(
PackageManager.FEATURE_BLUETOOTH_LE) ? true : false;
// Use this check to determine whether BLE is supported on the device.
if (isBleAvailable && apiJBorAbove) {
// 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);
mBluetoothAdapter = bluetoothManager.getAdapter();
// Ensures Bluetooth is available on the device and it is enabled.
// If not, displays a dialog requesting user permission to enable
// Bluetooth.
if (mBluetoothAdapter == null || !mBluetoothAdapter.isEnabled()) {
startActivity(new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE));
}
BluetoothAdapter.LeScanCallback mLeScanCallback =
new BluetoothAdapter.LeScanCallback() {
@Override
public void onLeScan(final BluetoothDevice device,
final int rssi, final byte[] scanRecord) {
runOnUiThread(new Runnable() {
@Override
public void run() {
String msg= device.getAddress();
// Log.d(TAG,msg);
// addItems(msg);
}
});
}
};
} NoClassDefFoundError是由API造成的，而不是基于PackageManager.FEATURE_BLUETOOTH_LE。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/23340265
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