java - 如何使用 AsyncTask<String, Void, String> 向目标发送多个请求

Question

我正在连接到一个网站并执行阅读器，然后更新一个 textView。这适用于一个项目。如何向网站发送多个请求？ 这是我正在做的<请引用

public class MainActivity extends AppCompatActivity {

    int counter = 0;
    TextView textViewGMT;
    TextView textViewCET;
    TextView textViewCN;
    TextView textViewKR;
    TextView textViewIST;
    String[] cities = {"London","Paris","Beijing","Seoul","Delhi"};

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

        textViewGMT = findViewById(R.id.textViewGMT);
        textViewCET = findViewById(R.id.textViewCET);
        textViewCN = findViewById(R.id.textViewCN);
        textViewKR = findViewById(R.id.textViewKR);
        textViewIST = findViewById(R.id.textViewIST);


        GetTime readerTask = new GetTime();
        String cityURL;
        for ( int i=0; i<cities.length; i++) {
            cityURL = "https://www.amdoren.com/api/timezone.php?"+cities[i];
            readerTask = new GetTime();
            readerTask.execute(cityURL);
        }

    }
    @Override
    protected void onStop(){
        super.onStop();
        Log.i("In onsStop()", "Executing finish()");
        finish();
    }
    public class GetTime extends AsyncTask<String, Void, String> {

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

            HttpURLConnection urlConnection;
            URL url;
            String result = "";


            try {
                url = new URL(strings[0]);
                urlConnection = (HttpURLConnection) url.openConnection();
                InputStream in = urlConnection.getInputStream();
                InputStreamReader reader = new InputStreamReader(in);
                int data = reader.read();
                while ( data != -1 ) {
                    char current = (char) data;
                    result += current;
                    data = reader.read();
                }
                counter++;
                return ( result );

            } catch (MalformedURLException e) {
                e.printStackTrace();
                return ( "***Failed in AsyncTask MalforemedURL***");
            } catch (IOException e) {
                e.printStackTrace();
                return ( "***Failed in AsyncTask IOException***");
            }
        }

        @Override
        protected void onPostExecute(String result) {
            super.onPostExecute(result);
            Log.i("WEBSITE CONTENT: ", result);

            ArrayList<String> arrayList = new ArrayList<>();

            try {
                JSONObject jsonObject = new JSONObject(result);
                System.out.println("Before String");

                System.out.println("After String");

                String main = jsonObject.getString("time");
                arrayList.add("Date: " );
                String[] arrOfStr = main.split(" ");
                arrayList.add(arrOfStr[0]);
                arrayList.add(" ");
                arrayList.add("Time:");
                arrayList.add(arrOfStr[1]);
                String desc = jsonObject.getString("timezone");
                Log.i("***main: ", main);
                Log.i("***description: ", desc);

                arrayList.add(" " );
                arrayList.add(desc);
                arrayList.add("\n");

                String textOut = "";
                for ( String each: arrayList ){
                    System.out.println(each);
                    textOut = textOut + each + "\n";
                }
               //If I could run it multiple times I can update the textViews.
               //This does not work at the moment.
                switch(counter){
                    case 0: textViewGMT.setText("London "+textOut);
                    case 1: textViewCET.setText("France "+textOut);
                    case 2: textViewCET.setText("China "+textOut);
                    case 3: textViewCET.setText("Korea"+textOut);
                    case 4: textViewCET.setText("India"+textOut);
                }
                System.out.println("TEXTOUT" + textOut);
            } catch (JSONException e) {
                e.printStackTrace();
            }

        }
    }
}

这会得到我传入的 URL/城市的时间信息。 想传递一个 URL 并用结果更新一个 textView，然后传递另一个 URL 并更新另一个 textView 或并行执行所有操作。 我怎样才能做到这一点？我需要多次实例化 AsyncTask 吗？

尝试循环运行阅读器，但失败了。

Answer 1

您可以使用 & 将要发送的值添加到您的 URL。 所以替换这一行:

cityURL = "https://www.amdoren.com/api/timezone.php?"+cities[i];

与

cityURL = "https://www.amdoren.com/api/timezone.php?"+cities[i]+"&value2=" + value2 + "&value3=" + value3;#

基本上:

URL + ? + value1=value1 & value2=value2