使用API​​> 23进行onFailure改造

Question

我无法解决问题。相同的代码提供API 21的onResponse，但提供API 28的onFailure。有什么想法吗？

public class MainActivity extends AppCompatActivity {

    ListView listView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        listView=(ListView)findViewById(R.id.list);

        final ArrayList<String> logins = new ArrayList<>();

        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl("http://172.28.123.182:8080")
                .addConverterFactory(GsonConverterFactory.create())
                .build();

        final TestService testService = retrofit.create(TestService.class);
        testService.getUsers().enqueue(new Callback<List<UserDto>>() {
            @Override
            public void onResponse(Call<List<UserDto>> call, Response<List<UserDto>> response) {
                if(response.body() == null) {
                    onFailure(call, null);
                    Log.d("tutaj", "blad1");
                    return;
                }
                List<UserDto> users = response.body();

                while (!users.isEmpty()){
                    logins.add(users.get(0).getLogin());
                    users.remove(0);
                }
            }

            @Override
            public void onFailure(Call<List<UserDto>> call, Throwable t) {
                Toast.makeText(MainActivity.this, "No users", Toast.LENGTH_LONG).show();
                Log.d("tutaj", "blad2");
            }
        });

        ArrayAdapter adapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1, android.R.id.text1, logins);

        listView.setAdapter(adapter);

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Intent intent = new Intent(MainActivity.this, SecondActivity.class);
                intent.putExtra("KEY", logins.get(position));
                startActivity(intent);
            }
        });
    }

    @Override
    protected void onResume() {
        super.onResume();
    }
}

我阅读了有关权限的信息，并且在API 23之后INTERNET是正常的，因此应该没有问题。我不知道问题是否出在代码或权限之类的东西上。

如果您需要有关清单文件或gradle构建的任何信息，请告诉我。问题是为什么它可以在爱好者API上工作。