Socket服务器控制器Android应用程序，Socket错误

Question

所以基本上我想为我的电脑创建某种控制器，在电脑上运行java套接字服务器。服务器正在工作，我已经试过了。此外，路由器中的端口转发也可以源代码在这里：

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
public class Server {
public static final String ANSI_RESET = "u001B[0m";
public static final String ANSI_GREEN = "u001B[32m";
public static final String ANSI_BOLD = "33[1m";
public static final String ANSI_RED = "u001B[31m";
public static void main(String[] args) throws IOException {
// Creating server instance
ServerSocket serverSocket = new ServerSocket(2000);
Socket socket = serverSocket.accept();
System.out.println(ANSI_GREEN + "Controller connected" + ANSI_RESET);
// Input Output streams
DataInputStream dataInputStream = new DataInputStream(socket.getInputStream());
DataOutputStream dataOutputStream = new DataOutputStream(socket.getOutputStream());
String command = "";
do {
command = dataInputStream.readUTF();
switch (command.trim()){
case "volume up":
Runtime.getRuntime().exec("cmd /c start src\sk\dzurik\main\volup.bat");
break;
case "volume down":
Runtime.getRuntime().exec("cmd /c start src\sk\dzurik\main\voldown.bat");
break;
default:
// Unknown command
break;
}

}while (!command.equals("stop"));
socket.close();
System.out.println(ANSI_RED + "Controller disconnected" + ANSI_RESET);
}
}

它应该与android应用程序交互，但我遇到了一个错误。我不太明白为什么会这样，下面是ActivityMain的源代码：

import androidx.appcompat.app.AppCompatActivity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
public class MainActivity extends AppCompatActivity {
private boolean connected;
private DataOutputStream dataOutputStream;
private Socket socket;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Pripájanie na server
try {
socket = new Socket("172.0.0.1",2000);
dataOutputStream = new DataOutputStream(socket.getOutputStream());
} catch (IOException e) {
Toast.makeText(MainActivity.this, "Not Connected!",
Toast.LENGTH_LONG).show();
}

Button VolumeUp = (Button) findViewById(R.id.VolumeUpButton);
VolumeUp.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
try {
send("volume up");
} catch (IOException e) {
e.printStackTrace();
}
}
});
Button VolumeDown = (Button) findViewById(R.id.VolumeDownButton);
VolumeDown.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
try {
send("volume down");
} catch (IOException e) {
e.printStackTrace();
}
}
});
Button DisconnectButton = (Button) findViewById(R.id.DisconnectButton);
DisconnectButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
try {
send("stop");
} catch (IOException e) {
e.printStackTrace();
}
}
});
}

public void send(String command) throws IOException {
if (socket != null){
dataOutputStream.writeUTF(command);
}
else Toast.makeText(MainActivity.this, "Socket is not defined",
Toast.LENGTH_SHORT).show();
}
public void disconnect() throws IOException {
if (socket != null){
socket.close();
}
else Toast.makeText(MainActivity.this, "Socket is not defined",
Toast.LENGTH_SHORT).show();
}
}

所以如果你能帮我，我会很感激的，<3

Answer 1

这样做的原因很愚蠢。当我从Stream加载数据时，它会显示nextLine，这意味着终点是，所以我永远无法得到那条线，因为我没有把它放在那里。