为什么没有发送http请求？ Android Studio - 改造

Question

I'm using Retrofit in Android studio - java. I'm trying to send an http request to a specific ip and when i try to sniff the packets while running the application in the emulator, i can't see any of the http packets on the list which sent to the specific ip.

This is where I try to send the http requests:

IService service = retrofit.create(IService.class);
        Call<LoginResponse> call = service.Login(loginRequest);
        call.enqueue(new Callback<LoginResponse>() {

            @Override
            public void onResponse(Call<LoginResponse> call, Response<LoginResponse> response)
            {
                Response = response.body();
            }

            @Override
            public void onFailure(Call<LoginResponse> call, Throwable t) {
                Response = new LoginResponse("Error with the communication with the server!", null);
            }
        });

        return (LoginResponse) Response;

This is my service:

public interface IService
{

    @POST("api/users/login")
    Call<LoginResponse> Login(@Body LoginRequest loginRequest);


}

Can't understand where I did wrong. Thanks.

Answer 1

In Android View Structure :

Manifest -> AndroidManifest.xml :

Also provide usesCleartextTraffic so it won't give you error to send resposne to ip

<?xml version="1.0" encoding="utf-8"?>
<manifest ...>
    <uses-permission android:name="android.permission.INTERNET" />
    <application
        ...
        android:usesCleartextTraffic="true"
        ...>
        ...
    </application>
</manifest>

Answer 2

Please check your URL, if it's http or https. If your URL is http and you got this error,

CLEARTEXT communication to ** not permitted by network security policy

it's related that cleartext support is disabled by default, starting with Android 9 (API level 28).

https://developer.android.com/training/articles/security-config#CleartextTrafficPermitted

In this case, please add this android:usesCleartextTraffic="true" in the application tag, of the AndroidManifest.xml.

<application
    android:name=".App"
    android:allowBackup="false"
    android:fullBackupContent="false"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme"
    android:usesCleartextTraffic="true">

If not, please post your error description. Hope to be helpful.