在写入器关闭后，Java继续使用文件

刚刚编写了一个java程序，将一些内容写入从手机接收的文件中，文件被写入，我想使用c#客户端读取该文件，但当试图读取文件时，我得到错误:文件正在被另一个进程使用，即使我确保我关闭了文件写入器…

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.File;
import java.net.InetAddress;
public class VRSC {
public static void main(String[] args) throws IOException {
    String username = System.getProperty("user.name");
    InetAddress ip = InetAddress.getLocalHost();
    File file = new File("C:/Users/"+username+"/Desktop/VRemote.cmd");

    Socket clientSocket = null;
    ServerSocket serverSocket = null;
    if (!file.exists()) {
        file.createNewFile();
    }
    try{
        serverSocket = new ServerSocket(5665);
        System.out.println("server started on port 5665");
        System.out.println("Please connect to: " + ip.getHostAddress());
        System.out.println("Waiting...");
        clientSocket = serverSocket.accept();
    }catch(Exception e){} //read & display the message
        //BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputS­tream()));
        Scanner in1 = new Scanner(clientSocket.getInputStream());
        String mes; 
        while(true){
            if (in1.hasNext())
            {   FileWriter fw = new FileWriter(file.getAbsoluteFile());

                mes=in1.nextLine();
                System.out.println("Command Received: "+mes);
                fw.write("VCommand: " + mes);
                fw.flush();
                fw.close();
            }
        }
    }
}

有没有人知道我如何让服务器写入文件，但允许c#客户端读取它并在之后立即更改它?