'rssi”值通常是用于衡量Bluetooth设备之间信号强度的指标。在Android平台下，BluetoothLeScanner扫描器库可以使用BluetoothScanCallback接口来获取扫描结果。扫描结果包含BluetoothDevice对象和一个名为ScanResult的对象。ScanResult对象包含了扫描到的设备的广告数据以及设备的rssi值。

以下是一个简单的示例代码，演示如何使用BluetoothLeScanner来扫描周围的Bluetooth设备，并获取其中一个设备的rssi值。

private BluetoothAdapter bluetoothAdapter;
private BluetoothLeScanner bluetoothLeScanner;

private ScanCallback scanCallback = new ScanCallback() {
    @Override
    public void onScanResult(int callbackType, ScanResult result) {
        BluetoothDevice device = result.getDevice();
        int rssi = result.getRssi();
        Log.d(TAG, "Found device: " + device.getName() + " (" + device.getAddress() + "), rssi: " + rssi);
    }

    @Override
    public void onScanFailed(int errorCode) {
        Log.e(TAG, "Scan failed with error code " + errorCode);
    }
};

private void startScanning() {
    bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    bluetoothLeScanner = bluetoothAdapter.getBluetoothLeScanner();
    ScanFilter scanFilter = new ScanFilter.Builder()
            .setDeviceName("MyDeviceName")
            .build();
    ArrayList scanFilters = new ArrayList<>();
    scanFilters.add(scanFilter);
    ScanSettings scanSettings = new ScanSettings.Builder()
            .setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY)
            .build();
    bluetoothLeScanner.startScan(scanFilters, scanSettings, scanCallback);
}

private void stopScanning() {
    bluetoothLeScanner.stopScan(scanCallback);
}

在上面的代码中，我们调用了BluetoothLeScanner.startScan()方法来开始扫描周围的设备。我们使用了ScanFilter对象来过滤掉我们不需要的设备，并使用ScanSettings对象来设置扫描模式。一旦有设备被扫描到，我们的ScanCallback对象会被触发，我们可以使用ScanResult对象来获取设备的rssi值。最后，我们可以使用BluetoothLeScanner.stopScan()方法来停止扫描。