为什么 NetworkOnMainThreadException 在 AsyncTask 中抛出？

Question

各位。 我正在使用抽屉 activity，使用片段更改内容，所以有 PerfilFragment，例如：

public class PerfilFragment extends Fragment {

    final CurrentView currentView = new CurrentView();

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_perfil, container, false);
    }

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        if (getActivity() != null) {
            getActivity().setTitle(R.string.menu_perfil);

            final CognitoCachingCredentialsProvider credentialsProvider;

            if (getContext() != null) {
                AWSConfiguration awsConfig = new AWSConfiguration(getContext());
                credentialsProvider = new CognitoCachingCredentialsProvider(
                        getContext(),
                        awsConfig
                );

                currentView.setCredentialsProvider(credentialsProvider);
                currentView.setView(view);

                final FloatingActionButton fab = view.findViewById(R.id.fab);
                fab.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                        new Insert().doInBackground(currentView);
                    }
                });
            }
        }
    }
}

类型 CurrentView 是一个内部 class，以及 Insert class:

class CurrentView {
    private CognitoCachingCredentialsProvider credentialsProvider;
    private View view;

    CognitoCachingCredentialsProvider getCredentialsProvider() {
        return credentialsProvider;
    }

    void setCredentialsProvider(CognitoCachingCredentialsProvider credentialsProvider) {
        this.credentialsProvider = credentialsProvider;
    }

    View getView() {
        return view;
    }

    void setView(View view) {
        this.view = view;
    }
}

class Insert extends AsyncTask<CurrentView, Void, Table> {

    private final static String TABLE = "perfil";

    @Override
    protected Table doInBackground(CurrentView... currentView) {
        AmazonDynamoDBClient dbClient;

        try {
            dbClient = new AmazonDynamoDBClient(currentView[0].getCredentialsProvider());
            Table perfilTable = Table.loadTable(dbClient, TABLE);

            Document perfilDocument = new Document();

            final EditText perfilNome = currentView[0].getView().findViewById(R.id.perfil_nome_txt);
            final EditText perfilDataNasc = currentView[0].getView().findViewById(R.id.perfil_datanasc_txt);
            final EditText perfilGenero = currentView[0].getView().findViewById(R.id.perfil_genero_txt);

            perfilDocument.put("userId", currentView[0].getCredentialsProvider().getCachedIdentityId());
            perfilDocument.put("nome", perfilNome.getText().toString());
            perfilDocument.put("datanasc", perfilDataNasc.getText().toString());
            perfilDocument.put("genero", perfilGenero.getText().toString());

            Document perfilInserido = perfilTable.putItem(perfilDocument);

            if (perfilInserido.containsKey("genero")) {
                DynamoDBEntry perfilInseridoGenero = perfilInserido.get("genero");

                if (perfilInseridoGenero != null) {
                    if (perfilInseridoGenero.asString().equals(perfilGenero.getText().toString())) {
                        Snackbar
                                .make(
                                        currentView[0].getView(),
                                        "Perfil atualizado!",
                                        Snackbar.LENGTH_LONG
                                )
                                .setAction("Atualizar", null)
                                .show();
                    }
                }
            }

            return perfilTable;
        } catch (Exception e) {
            Log.e("EXCEPTION", e.getMessage(), e);
            return null;
        }
    }
}

异常在 doInBackground 方法中抛出，在以下行： Table perfilTable = Table.loadTable(dbClient, TABLE);

我错过了什么？

Answer 1

正如 AWS 开发者论坛的用户 awsvbk 对我的回答：

You need to invoke the execute() method as opposed to the doInBackground() method. Calling execute() will internally call the doInBackground() method of AsyncTask in a background thread.

new Insert().execute(<PARAMS>)

If you still face any other issue with the DynamoDB Document Model SDK, please cut us an issue on GitHub on https://github.com/aws/aws-sdk-android