大家好，我最近依然在Android上使用Retrofit API抓取Json時，遇到底下這個問題：

這個是API的規格：

Postman有回傳一個數字給我，但我在Android上不知道要怎麼取得這個數字
這邊是我的程式碼：

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl("http://10.25.7.167:62678/") 
                .addConverterFactory(GsonConverterFactory.create())  
                .build();
        ApiGet apiGet =retrofit.create(ApiGet.class);
        Call<test> call = apiGet.getPost();
        call.enqueue(new Callback<test>() {
            @Override
            public void onResponse(Call<test> call, Response<test> response) {
                Log.d("API","是:"+response.body().getInteger());
            }

            @Override
            public void onFailure(Call<test> call, Throwable t) {
                Log.d("API","Fail:"+t.toString());
            }
        });
    }
    public interface ApiGet{
        @GET("api/Commodity/GetIdCommodityByIdCommodityDetail?idCommodityDetail=3474")
        Call<test> getPost();
    }
    public class test{
        private int integer;

        public int getInteger() {
            return integer;
        }

        public void setInteger(int integer) {
            this.integer = integer;
        }
    }
}

會出這個錯誤

D/API: Fail:com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected BEGIN_OBJECT but was NUMBER at line 1 column 5 path $