Android - 网络请求不起作用并且应用程序停止工作

Question

我有一个 android 应用程序，我想从服务器获取请求并将其显示给用户，但它不工作并且应用程序停止工作。这是我的代码：

 URL url;
    try {
        url = new URL("http://accounting.hamyar.net/IBSng/user/index.php?normal_username=7325238658&normal_password=hamidreza3329");
        URLConnection conn = url.openConnection();
        conn.setRequestProperty("Cookie", "IBS_SESSID=hlpjpnm8hdrf84n7igk0m5n9v6; session_id=f49f028f0c3b87719638136ce5cd5f23090eca5e");
        BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));

        String inputLine;

        while ((inputLine = br.readLine()) != null) {
            if (inputLine.contains("<td class=") && inputLine.contains("Middle") && inputLine.contains("<sub>"))
            {
                String chargenum =  getBetween(inputLine, "<td class=\"List_Col\" valign=\"Middle\" >", "<sub>").trim();

                String chargeunit = getBetween(inputLine, "<sub>", "</sub>");
                String gig = chargenum.trim() + chargeunit.trim();
                System.out.println("Your gig is "+gig);
            }
        }
        br.close();



    } catch (IOException e) {
    }
}
public static String getBetween(String str, String open, String close) {
    if (str == null || open == null || close == null) {
        return null;
    }
    int start = str.indexOf(open);
    if (start != -1) {
        int end = str.indexOf(close, start + open.length());
        if (end != -1) {
            return str.substring(start + open.length(), end);
        }
    }
    return null;
}

Answer 1

您必须在 AndroidManifest.xml 外部的 Application 标记中添加 Internet 权限，如下所示：

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

Answer 2

您是否在线程中运行它，因为它看起来不像。尝试在异步任务中运行它。尝试将以下代码作为类添加到您的项目中：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;

import android.os.AsyncTask;

public class MyBackgroundTask extends AsyncTask<Void, Void, String> {

    @Override
    protected String doInBackground(Void... params) {
        URL url;
        try {
            url = new URL(
                    "http://accounting.hamyar.net/IBSng/user/index.php?normal_username=7325238658&normal_password=hamidreza3329");
            URLConnection conn = url.openConnection();
            conn.setRequestProperty(
                    "Cookie",
                    "IBS_SESSID=hlpjpnm8hdrf84n7igk0m5n9v6; session_id=f49f028f0c3b87719638136ce5cd5f23090eca5e");
            BufferedReader br = new BufferedReader(new InputStreamReader(
                    conn.getInputStream()));

            String inputLine;

            while ((inputLine = br.readLine()) != null) {
                if (inputLine.contains("<td class=")
                        && inputLine.contains("Middle")
                        && inputLine.contains("<sub>")) {
                    String chargenum = getBetween(inputLine,
                            "<td class=\"List_Col\" valign=\"Middle\" >",
                            "<sub>").trim();

                    String chargeunit = getBetween(inputLine, "<sub>", "</sub>");
                    String gig = chargenum.trim() + chargeunit.trim();
                    System.out.println("Your gig is " + gig);
                }
            }
            br.close();

        } catch (IOException e) {
        }

        return "";
    }

    public static String getBetween(String str, String open, String close) {
        if (str == null || open == null || close == null) {
            return null;
        }
        int start = str.indexOf(open);
        if (start != -1) {
            int end = str.indexOf(close, start + open.length());
            if (end != -1) {
                return str.substring(start + open.length(), end);
            }
        }
        return null;
    }

}

然后像这样从您的活动中调用它：new MyBackgroundTask().execute();