android访问mysql数据库

@RestController
@RequestMapping("/api")
public class UserController {

    @Autowired
    private UserRepository userRepository;

    @GetMapping("/users")
    public List<User> getUsers() {
        return userRepository.findAll();
    }

    @PostMapping("/users")
    public User createUser(@RequestBody User user) {
        return userRepository.save(user);
    }
}

public class MainActivity extends AppCompatActivity {

    private static final String BASE_URL = "https://yourserver.com/api/";

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

        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl(BASE_URL)
                .addConverterFactory(GsonConverterFactory.create())
                .build();

        UserService userService = retrofit.create(UserService.class);

        Call<List<User>> call = userService.getUsers();
        call.enqueue(new Callback<List<User>>() {
            @Override
            public void onResponse(Call<List<User>> call, Response<List<User>> response) {
                if (response.isSuccessful()) {
                    List<User> users = response.body();
                    // 处理用户数据
                }
            }

            @Override
            public void onFailure(Call<List<User>> call, Throwable t) {
                // 处理错误
            }
        });
    }
}