Android 蓝牙ble连接前一定需要配对么？

Android 蓝牙ble连接前一定需要配对么？从网上查资料有人专做配对的，

但是我要求连接是不需要配对的。我按照官方文档上写的代码，发现写出来连接前需要配对，有没有做过的人帮忙解答一下。

BLE是不需要配对的，可能你找到的代码不对吧

public boolean connect(final String address) {
if (mBluetoothAdapter == null || address == null) {
L.e("BluetoothAdapter not initialized or unspecified address.");
return false;
}

    //如果以前连接过
    if (mBluetoothDeviceAddress != null && address.equals(mBluetoothDeviceAddress)
            && mBluetoothGatt != null) {
        L.e("Trying to use an existing mBluetoothGatt for connection.");
        if (mBluetoothGatt.connect()) {
            mConnectionState = STATE_CONNECTING;
            return true;
        } else {
            return false;
        }
    }
    //没有连接过
    bluetoothDevice = mBluetoothAdapter.getRemoteDevice(address);
    if (bluetoothDevice == null) {
        L.e("Device not found.  Unable to connect.");
        return false;
    }else{
        //false代表自动连接
        mBluetoothGatt = bluetoothDevice.connectGatt(this, false, mGattCallback);
        L.e("Trying to create a new connection.");
        mBluetoothDeviceAddress = address;
        mConnectionState = STATE_CONNECTING;
        return true;
    }
}

请问为什么我的手机蓝牙检测不到从机呢？