Question

我有一个班级

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.ArrayList;
import java.lang.Exception;
import java.net.HttpURLConnection;
public class HttpURLConnectionExample  {
    private final String USER_AGENT = "Mozilla 5.0";
    // HTTP GET request
    public ArrayList<dispencer> sendGet() throws Exception {
        String url = "http://192.168.1.9";
        URL obj = new URL(url);
        HttpURLConnection con = (HttpURLConnection) obj.openConnection();
        // optional default is GET
        con.setRequestMethod("GET");
        //add request header
        con.setRequestProperty("User-Agent", USER_AGENT);
        int responseCode = con.getResponseCode();
        System.out.println("\nSending 'GET' request to URL : " + url);
        System.out.println("Response Code : " + responseCode);
        BufferedReader in = new BufferedReader(
                new InputStreamReader(con.getInputStream()));
        String inputLine;
        StringBuffer response = new StringBuffer();
        while ((inputLine = in.readLine()) != null) {
        response.append(inputLine);
    }
    in.close();
    //print result
    ArrayList<dispencer> dispList = new ArrayList<dispencer>();
    String[] strRows = response.toString().split("@");
    for (int i= 0; i <strRows.length; i++) {
        dispencer disp = new dispencer(strRows[i]);
        if (!disp.isOk) continue;
        dispList.add(disp);
        System.out.println(disp.indirizzo);
    }
    return dispList;
}
}

我这样称呼方法sendGet。

        HttpURLConnectionExample httpFnd= new HttpURLConnectionExample();
            ArrayList<dispencer> listAr = new ArrayList<dispencer>();
            try{
                listAr = httpFnd.sendGet();
            }
            catch (Exception Exception){

                fndLayout.setVisibility(View.GONE);
                System.out.println("exception handled");
            }

每当我尝试调用 sendGet 时，我总是会处理消息异常并且永远不会收到我的arrayList，就像连接从未建立一样。当我调用该方法时，我也会收到此错误

D / NetworkSecurityConfig：未使用指定的网络安全配置平台默认

，这是我的问题的原因吗？

感谢您的帮助。

编辑我看到我需要使用asyncTask来预防异常Andy建议我如何实现它？

Answer 1

试试这个：

class Loading extends AsyncTask {

@Override

protected Void doInBackground( Void... arg0)

{

// your code here

return null;

}

@Override

protected void onPreExecute()

{

//your code here

super.onPreExecute();

}

@Override

protected void onPostExecute(Void result)

{

//your code here

super.onPostExecute(result);

}

}//Loading

您是否记得在AndroidManifest.xml中添加此行：

<uses-permission android:name="android.permission.INTERNET"/>

和

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

Android HttpURLConnection总是抛出异常

1 个答案: