Java客户端无法接收Python服务器发送的位置列表数据求助

我正在开发一款基于位置提醒的待办APP，核心功能是用户靠近指定位置时推送对应任务。主界面用ListView展示用户添加的所有位置，这些位置以JSON格式存储在数据库中。

用户登录流程正常：数据发往Python服务器，校验账号密码后返回消息，随后跳转至主界面。但在主界面onCreate方法中获取当前登录用户的位置列表时，Java客户端无法接收到服务器发送的数据。

相关代码 #

SocketTask类（服务器收发数据） #

package com.example.yearprojectfinal;

import android.os.AsyncTask;
import android.util.Log;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.nio.charset.StandardCharsets;

public class SocketTask extends AsyncTask<String, Void, String>
{
    private final static String IP_ADDRESS = "192.168.1.218";
    private final static int PORT = 50001;

    private Socket socket;
    private String sendingStr = "";
    private String receivingStr = "";

    public SocketTask(String str1) {
        this.sendingStr = str1;
    }

    @Override
    protected String doInBackground(String... arrStrings)
    {
        try
        {
            this.socket = new Socket(IP_ADDRESS, PORT);
            send(this.sendingStr);
            receive();
            this.socket.close();
        }
        catch (Exception e)
        {
            Log.e("Exception", e.toString());
        }
        return this.receivingStr;
    }

    private void send(String sendingStr)
    {
        try
        {
            OutputStream outputStream = this.socket.getOutputStream();
            byte[] bytes = sendingStr.getBytes(StandardCharsets.UTF_8);
            outputStream.write(bytes);
            outputStream.flush();
            System.out.println("sent");
        }
        catch (Exception e)
        {
            Log.e("Exception", e.toString());
        }
    }


    private void receive()
    {
        try
        {
            System.out.println("trying to receive");
            InputStream inputStream = socket.getInputStream();
            System.out.println(inputStream);
            ByteArrayOutputStream baos = new ByteArrayOutputStream();

            int c;
            while ((c = inputStream.read()) != -1)
            {
                baos.write((char) c);
            }
            System.out.println("hello");
            byte[] bytes = baos.toByteArray();
            receivingStr = new String(bytes, StandardCharsets.UTF_8);
            inputStream.close();
            Log.d("str received", receivingStr);
        }
        catch (Exception e)
        {
            Log.e("Exception", e.toString());
        }
    }
}

该类负责与服务器收发数据，除获取位置列表场景外，其他功能均正常。

调用SocketTask的工具函数 #

private String sendAddLocationDataToServer(String strToSend)
{
    try
    {
        SocketTask send1 = new SocketTask(strToSend);
        String strReceived = send1.execute().get();
        return strReceived;
    }
    catch (ExecutionException | InterruptedException e)
    {
        Log.e("Exception", e.toString());
    }
    return "something went wrong with execution";
}

获取用户位置列表的调用代码 #

public ArrayList<Location> getLocationListForUser()
{
    String dataStrToSend = "requesting location list," + connectedUsername;

    // 发送长度头部
    String resultStr = sendAddLocationDataToServer(
            String.format("%05d", activityName.length()) + activityName
                    + String.format("%05d", dataStrToSend.length()) + dataStrToSend);

    Gson gson = new Gson();
    Type listType = new TypeToken<ArrayList<Location>>(){}.getType();
    ArrayList<Location> locationsListByUsername = gson.fromJson(resultStr, listType);

    return locationsListByUsername;
}

排查情况 #

已确认Python服务器运行正常且数据已发送，但Java客户端在SocketTask的receive方法中执行以下代码时出现异常：

int c;
while ((c = inputStream.read()) != -1)
{
    baos.write((char) c);
}           

日志仅输出：

2022-12-21 15:55:43.640 14239-14242/com.example.yearprojectfinal I/earprojectfina: Thread[3,tid=14242,WaitingInMainSignalCatcherLoop,Thread*=0x7a3c35e33a60,peer=0x13200238,"Signal Catcher"]: reacting to signal 3
2022-12-21 15:55:43.640 14239-14242/com.example.yearprojectfinal I/earprojectfina:
2022-12-21 15:55:43.696 14239-14242/com.example.yearprojectfinal I/earprojectfina: Wrote stack traces to tombstoned

需求 #

求解决思路或排查方案。

内容的提问来源于stack exchange，提问作者nortain32