工作代码突然停止工作--为什么？[副本]

Question

我一直在使用一个异步任务，通过REST API将数据从应用程序发送或提取到数据库，反之亦然。我在我的几个项目（已完成）中使用的代码也是我在其他新项目中使用的代码。我现在创建了一个新项目，工作的异步代码不再取数据了，但是我在以前的项目中粘贴的相同代码，它工作得很好。我有一个新的项目明天开始，我希望我易于使用的代码在新的项目中也能很好地工作。被认为是在清单中添加了INTERNET权限。mainactivity.java中的代码，它应该在postExecute时显示来自数据库的Toast

import androidx.appcompat.app.AppCompatActivity;

import android.os.AsyncTask;
import android.os.Bundle;
import android.widget.Toast;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
    String name;
    ArrayList<String> NAME=new ArrayList<String>();

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

    public class getpostcount extends AsyncTask<String, String, String> {
        String db_url;


        @Override
        protected void onPreExecute() {
            //   Toast.makeText(newsFeed.this, "Loading........", Toast.LENGTH_SHORT).show();
            db_url = "http://testprasis.000webhostapp.com/getshopname.php";

        }

        @Override
        protected String doInBackground(String... args) {

            try {
                URL url = new URL(db_url);
                HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
                httpURLConnection.setRequestMethod("POST");
                httpURLConnection.setDoOutput(true);
                httpURLConnection.setDoInput(true);
                OutputStream outputStream = httpURLConnection.getOutputStream();
                BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));

                bufferedWriter.flush();
                bufferedWriter.close();
                outputStream.close();

                InputStream inputStream = httpURLConnection.getInputStream();
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream, "iso-8859-1"));
                StringBuffer buffer = new StringBuffer();
                StringBuilder stringBuilder = new StringBuilder();
                String line = "";

                while ((line = bufferedReader.readLine()) != null) {
                    stringBuilder.append(line);

                }
                bufferedReader.close();
                inputStream.close();
                httpURLConnection.disconnect();
                String data = stringBuilder.toString().trim();

                String json;

                InputStream stream = new ByteArrayInputStream(data.getBytes(StandardCharsets.UTF_8));
                int size = stream.available();
                byte[] buffer1 = new byte[size];
                stream.read(buffer1);
                stream.close();

                json = new String(buffer1, "UTF-8");
                JSONArray jsonArray = new JSONArray(json);

                for (int i = 0; i <= jsonArray.length(); i++) {
                    JSONObject jsonObject = jsonArray.getJSONObject(i);
                    if (jsonObject.getString("id") != null) {
                        name = jsonObject.getString("shop_name");

                        NAME.add(name);


                    }
                }


                return null;


            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } catch (JSONException e) {
                e.printStackTrace();
            }
//
            return null;
        }

        @Override
        protected void onPostExecute(String s) {
              Toast.makeText(MainActivity.this,NAME.get(0), Toast.LENGTH_SHORT).show();
        }
    }
}

logcat：

2019-11-27 17:13:00.044 26790-26790/com.sheershakx.hisab E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.sheershakx.hisab, PID: 26790
    java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
        at java.util.ArrayList.get(ArrayList.java:437)
        at com.sheershakx.hisab.MainActivity$getpostcount.onPostExecute(MainActivity.java:119)
        at com.sheershakx.hisab.MainActivity$getpostcount.onPostExecute(MainActivity.java:38)
        at android.os.AsyncTask.finish(AsyncTask.java:695)
        at android.os.AsyncTask.access$600(AsyncTask.java:180)
        at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:712)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:201)
        at android.app.ActivityThread.main(ActivityThread.java:6810)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:873)

Answer 1

为什么突然就不起作用了？

实际上，它可以工作，但在Android版本的AndroidP。因为Android P默认使用HTTPS。这意味着，如果您在应用程序中使用未加密的HTTP请求，则该应用程序在除Android P以外的所有Android版本（较低版本）中都能正常工作。

如何让它在AndroidP上运行？

null

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="true">nikit19.github.io</domain>
    </domain-config>
</network-security-config>

<?xml version="1.0" encoding="utf-8"?>
<manifest ... >
    <application android:networkSecurityConfig="@xml/network_security_config"
                    ... >
        ...
    </application>
</manifest>

只需在应用程序内部的清单中使用它

android:usesCleartextTraffic="true"