I am trying to open my bitcoin-qt wallet with bitcoinj. I have this simple code:
private static final File WALLET_FILE = new File("__PATH__");
public static void main(String[] args) {
    Wallet wallet;
    try {
        wallet = Wallet.loadFromFile(WALLET_FILE);
    } catch (IOException e) {
    System.out.println("Couldn't open wallet: " + e);
    return;
    }
    System.out.println("Balance: " + wallet.getBalance());
}
I get an error:
Couldn't open wallet: com.google.protobuf.InvalidProtocolBufferException: Protocol message contained an invalid tag (zero).
How to solve this?