在PHP中，$id变量期望从客户端接收一个整数值，然而，当id值作为一个整数从客户端使用POST请求方法发送到PHP脚本时，在PHP中，当脚本上载到WAMP服务器上时，它会自动转换为字符串类型，另一方面，当脚本上载到Bluehost服务器上时，id值仍然是一个整数，并且不转换为字符串，这是我想要的。

下面是一个简单的PHP脚本：

<?php

$id = $_POST["id"];

if (is_int($id))
    echo "It is integer"; // It will print this if the PHP script was uploaded to the Bluehost server.
else if (is_string($id))
    echo "It is string"; // It will print this if the PHP script was uploaded to the WAMP server.

从客户端发送的id值是通过Android应用程序发送的，下面是我将id值发送到PHP脚本的方式：

• 改造管理器类 *

public class RetrofitManager {

    private static RetrofitManager.Api api;

    public static RetrofitManager.Api getApi() {
        if (api == null)
            api = new Retrofit.Builder()
                .baseUrl("http://192.151.5.721/API/")
                .client(new OkHttpClient.Builder().readTimeout(3, TimeUnit.MINUTES).writeTimeout(3, TimeUnit.MINUTES).connectTimeout(25, TimeUnit.SECONDS).build())
                .addConverterFactory(GsonConverterFactory.create())
                .addCallAdapterFactory(RxJava3CallAdapterFactory.create())
                .build()
                .create(Api.class);

        return api;
    }

    public interface Api {

        @FormUrlEncoded
        @POST("Countries/Get.php")
        Single<CountryModelResponse> getCountries(@Field("id") int countryId);

    }

}

• 国家/地区存储库类 *

public class CountriesRepository {

    public LiveData<Object> getCountries(Context context) {
        MutableLiveData<Object> mutableLiveData = new MutableLiveData<>();
        PublishSubject<String> retrySubject = PublishSubject.create();

        RetrofitManager.getApi().getCountries(Navigation.findNavController(MainActivity.activityMainBinding.activityMainFragmentContainerViewContainer).getPreviousBackStackEntry() == null ? SharedPreferencesManager.getIntegerValue(context, SharedPreferencesManager.Keys.COUNTRY_ID.name()) : -1)
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .doOnSubscribe(mutableLiveData::setValue)
            .doOnError(throwable -> {
                LinkedHashSet<Object> linkedHashSet = new LinkedHashSet<>();
                linkedHashSet.add(!Utils.isInternetConnected(context) ? 100 : throwable instanceof SocketTimeoutException ? 200 : 300);
                linkedHashSet.add(retrySubject);
                mutableLiveData.setValue(linkedHashSet);
            })
            .retryWhen(throwableFlowable -> throwableFlowable.flatMap(throwable -> retrySubject.toFlowable(BackpressureStrategy.DROP).take(1), (throwable, s) -> s))
            .subscribe(countryModelResponse -> {
                if (countryModelResponse.getRequestStatus() == 100)
                    mutableLiveData.setValue(countryModelResponse);
                else {
                    LinkedHashSet<Object> linkedHashSet = new LinkedHashSet<>();
                    linkedHashSet.add(300);
                    linkedHashSet.add(retrySubject);
                    mutableLiveData.setValue(linkedHashSet);
                }
            });

        return mutableLiveData;
    }

}

我不知道为什么这两个服务器之间会出现这种行为差异。
我使用的是最新版本的PHP和WAMP服务器。