java - 如何在 Dart 中使用 RawSocket？

问题描述

我有服务器套接字，当我使用 java 设置 socket.setSoLinger(true,0); 访问它时效果很好。我正在尝试使用 dart 实现 java 客户端代码，但我不断收到错误消息。也需要时间才能得到错误。飞镖应该很快！

在 java 中，我打开套接字为socketOut = new DataOutPutStream(socket.getOutputStream()); 和 socketIn = new DataInputStream(socket.getInputStream());

而且我可以使用socketOut.write(queryStr.getBytes()); 写，我可以使用response += socketIn.readLine(); 读书。

对于我的演示 Dart 项目，我编写了以下代码，但我不断收到以下错误。

错误：

Unhandled exception:
SocketException: OS Error: Broken pipe, errno = 32, address = ***.***.***.***, port = 48620
#0      _rootHandleUncaughtError.<anonymous closure> (dart:async/zone.dart:1112:29)
#1      _microtaskLoop (dart:async/schedule_microtask.dart:41:21)
#2      _startMicrotaskLoop (dart:async/schedule_microtask.dart:50:5)
#3      _runPendingImmediateCallback (dart:isolate/runtime/libisolate_patch.dart:115:13)
#4      _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:172:5)

飞镖代码：

import 'package:untitled/untitled.dart' as untitled;
import 'dart:io';
import 'dart:async';

Socket socket;
String _dataToBeSent = "00802020N0307809491508590203000000000000490012001629   01700CD0";
var reply;

// TODO: MAIN
main(List<String> arguments) {

  _remoteServerConnect();

}

// TODO: REMOTE SERVER  CONNECT
void _remoteServerConnect() async {
  try {
      var socket = await Socket.connect('***.***.***.***', *****);
      socket.writeln('$_dataToBeSent\n');

      await for (var data in socket) {
        reply = new String.fromCharCodes(data).trim();
        print("reply: $reply");

        socket.close();
        socket.destroy();
      } // await socket

      socket.handleError((data) {
        print("error: $data");
      });

  } on Error catch (e) {
    print(e.toString());
  } on Exception catch (f) {
    print(f.toString());
  }
}

我不知道。但是有些事情告诉我我应该使用 RawSocket。我的问题是如何在 Dart 中使用 RawSocket？

UPDATE-1：阅读链接后，我设法重新编码我的套接字，如下所示。但是这次我遇到了 socket.write 错误。

// TODO: REMOTE SERVER  CONNECT
void _remoteServerConnect()  {
  Socket.connect('***.***.***.***', *****).then((Socket sock) {
    socket = sock;
    socket.listen(dataHandler,
        onError: errorHandler,
        onDone: doneHandler,
        cancelOnError: false);
  }).catchError((AsyncError e) {
    print("Unable to connect: $e");
    exit(1);
  });

  print(_dataToBeSent);
  socket.write(_dataToBeSent);
}

void dataHandler(data){
  print(new String.fromCharCodes(data).trim());
}

void errorHandler(error, StackTrace trace){
  print(error);
}

void doneHandler(){
  socket.destroy();
  exit(0);
}

我在“socket.write(_dataToBeSent);”中遇到错误一行说在 null 上调用了“write”方法。

00802020N0307809491508590203000000000000490012001629   01700CD0
Unhandled exception:
NoSuchMethodError: The method 'write' was called on null.
Receiver: null
Tried calling: write(""00802020N0307809491508590203000000000000490012001629   01700CD0"")
#0      Object.noSuchMethod (dart:core/runtime/libobject_patch.dart:48:5)
#1      _remoteServerConnect (file:///home/capital/IdeaProjects/untitled/bin/main.dart:31:10)
#2      main (file:///home/capital/IdeaProjects/untitled/bin/main.dart:13:3)
#3      _startIsolate.<anonymous closure> (dart:isolate/runtime/libisolate_patch.dart:287:32)
#4      _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:171:12)

UPDATE-2：如果我使用 Future 比我看不到任何数据，但它运行没有错误。

// TODO: 远程服务器连接

Future _remoteServerConnect() async {
  await Socket.connect('***.***.***.***', ******).then((Socket sock) {
    socket = sock;
    socket.listen(dataHandler,
        onError: errorHandler,
        onDone: doneHandler,
        cancelOnError: false);
  }).catchError((AsyncError e) {
    print("Unable to connect: $e");
    exit(1);
  });

  print(_dataToBeSent);
  await socket.write(_dataToBeSent);
}

void dataHandler(data){
  print(new String.fromCharCodes(data).trim());
}

void errorHandler(error, StackTrace trace){
  print(error);
}

void doneHandler(){
  socket.destroy();
  exit(0);
}

结果：

00802020N02018092108262302030000000000005494490012001629   00000000
Process finished with exit code 0

标签： javasocketssocket.iodartflutter

Future _remoteServerConnect() async { socket = await Socket.connect('***.***.***.***', ******).then((Socket sock) { sock.listen(dataHandler, onError: errorHandler, onDone: doneHandler, cancelOnError: false); }).catchError((AsyncError e) { print("Unable to connect: $e"); exit(1); }); print(_dataToBeSent); await socket.write(_dataToBeSent); } void dataHandler(data){ print(new String.fromCharCodes(data).trim()); } void errorHandler(error, StackTrace trace){ print(error); } void doneHandler(){ socket.destroy(); exit(0); }

java - 如何在 Dart 中使用 RawSocket？

问题描述

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