NoClassDefFoundError的类加载了BLE扫描回调过程 [英] NoClassDefFoundError during class load for BLE scanning callback
问题描述
我不断获取的的NoClassDefFoundError 时，我的类加载。
在code摘自 BluetoothLeGatt 项目 -
http://developer.android.com/samples/BluetoothLeGatt/project.html
我的code：
//设备扫描回调。
私人BluetoothAdapter.LeScanCallback mLeScanCallback =
新BluetoothAdapter.LeScanCallback（）{... //java.lang.NoClassDefFoundError @覆盖
公共无效onLeScan（最终BluetoothDevice类设备，
最终诠释RSSI，最后一个字节[] scanRecord）{
runOnUiThread（新的Runnable（）{
@覆盖
公共无效的run（）{
弦乐味精= device.getAddress（）; Log.d（TAG，味精）;
为addItems（MSG）;
}
}）;
}
};
有人建议该错误是因为我的设备不支持BLE但我想摆脱这种错误的任何设备。所以，如果它不支持BLE功能，则直接跳过此错误与其他调用此继续 BluetoothAdapter.LeScanCallback 。
注意：
请参阅this我的previous SO发布更多的澄清。
把BLE功能检查作为第一线的onCreate（）不停止崩溃 -
@覆盖
公共无效的onCreate（捆绑savedInstanceState）{ 如果（！bleCheck（））{
Toast.makeText（getApplicationContext（），R.string.ble_not_supported，
Toast.LENGTH_SHORT）.show（）;
完（）;
} 在code的//休息
//调用到BLE扫描按钮单击导致错误..
} 私人布尔bleCheck（）{
布尔结果= FALSE;
如果（getPackageManager（）。
hasSystemFeature（PackageManager.FEATURE_BLUETOOTH_LE））{
结果=真;
}
返回结果;
}
由于 BluetoothAdapter.LeScanCallback 为在API级别18 ; 来源，这code将需要一个API等级检定也。下面是我去了这一点，没有宣布回调作为私人使用，但条件下：
布尔apiJBorAbove = android.os.Build.VERSION.SDK_INT＆GT; = android.os.Build.VERSION_ codeS.JELLY_BEAN_MR2？真正
：假的;布尔isBleAvailable = getPackageManager（）。hasSystemFeature（
PackageManager.FEATURE_BLUETOOTH_LE）？真假;
//使用这个检查，以确定是否BLE支持设备上。
如果（isBleAvailable＆安培;＆安培; apiJBorAbove）{
//初始化一个蓝牙适配器。
//对于API 18级以上，获得一个参考
// BluetoothAdapter通过BluetoothManager。
最后BluetoothManager bluetoothManager =（BluetoothManager）getSystemService（Context.BLUETOOTH_SERVICE）;
mBluetoothAdapter = bluetoothManager.getAdapter（）;//确保蓝牙设备上可用，并已启用。
//如果没有，则显示请求的用户的权限，以使一个对话
// 蓝牙。
如果（mBluetoothAdapter == NULL ||！mBluetoothAdapter.isEnabled（））{
startActivity（新意图（BluetoothAdapter.ACTION_REQUEST_ENABLE））;
}BluetoothAdapter.LeScanCallback mLeScanCallback =
新BluetoothAdapter.LeScanCallback（）{ @覆盖
公共无效onLeScan（最终BluetoothDevice类设备，
最终诠释RSSI，最后一个字节[] scanRecord）{
runOnUiThread（新的Runnable（）{
@覆盖
公共无效的run（）{
弦乐味精= device.getAddress（）;
// Log.d（TAG，味精）;
//为addItems（MSG）;
}
}）;
}
};
}
的的NoClassDefFoundError 是由于API，而不是依据 PackageManager.FEATURE_BLUETOOTH_LE 在
I am keep on getting the NoClassDefFoundError when my class is loaded.
The code is taken from BluetoothLeGatt project -
http://developer.android.com/samples/BluetoothLeGatt/project.html
My code:
// 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);
}
});
}
};
Someone suggested that the error is because my device doesn't support BLE but I want to get rid of this error for any device. So if it doesn't support BLE feature then simply skip this error else continue with the call to this BluetoothAdapter.LeScanCallback.
NOTE:
See this my previous SO post for more clarification.
Putting the BLE feature check as the first line onCreate() doesn't stop the crash --
@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;
}
As BluetoothAdapter.LeScanCallback was Added in API level 18 ; Source, this code would need a API level check also. Here's how i have gone about this, not declared the callback as private but under the condition:
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);
}
});
}
};
}
The NoClassDefFoundError is due to the API , not on the basis of PackageManager.FEATURE_BLUETOOTH_LE.
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