关于socket发送数据需要注意的问题

	ServerSocket server = null;
	try {
		server = new ServerSocket(AppProvider.PORT, 0);
		BufferedReader in;
		BufferedWriter out;
		while (true) {
			Socket client = server.accept();
			
			in = new BufferedReader(new InputStreamReader(client.getInputStream()));
			out = new BufferedWriter(new OutputStreamWriter(client.getOutputStream()));
			out.flush();
			try {
				String request = in.readLine();
				String response = processMessage(request);
				if (response != null) {
					out.write(response);
					out.newLine();  
					out.flush();
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
			
			in.close();
			out.close();
			client.close();
		}
	} catch (IOException e) {
		e.printStackTrace();
	} finally {
		if (server != null && !server.isClosed()) {
			try {
				server.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}

//测试示例
public void upSocket(){
    //Java中使用Socket进行文件上传的基本流程如下所示：
    //创建客户端Socket对象并连接到服务器。可以通过指定IP地址和端口号来完成连接操作。
    String serverIp = "服务器IP"; // 设置服务器IP地址
    int port = 8080; // 设置服务器监听的端口号

    Socket clientSocket = null;
    InputStream inputStream = null;
    OutputStream outputStream = null;
    try {
        clientSocket = new Socket(serverIp, port);
        //获取输入/输出流对象，分别用于读取要发送的文件内容和写入从服务器返回的数据。
        String filePath = "要上传的文件路径";
        File fileToSend = new File(filePath);
        if (!fileToSend.exists()) {
            throw new IllegalArgumentException("指定的文件不存在！");
        }
        inputStream = new FileInputStream(filePath); // 设置要上传的文件路径
        outputStream = clientSocket.getOutputStream();
        //将文件内容逐段读取后写入输出流，直到文件结尾。
        byte[] buffer = new byte[4096]; // 设置每次读取的字节大小
        int bytesRead;
        while ((bytesRead = inputStream.read(buffer)) != -1) {
            outputStream.write(buffer, 0, bytesRead);
        }
        outputStream.flush(); // 确保数据被全部写入输出流
    } catch (IOException e) {
        e.printStackTrace();
    }finally {
        //关闭输入/输出流和Socket连接。
        try {
            inputStream.close();
            outputStream.close();
            clientSocket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

public static void main(String[] args) throws IOException {
    int portNumber = 8080;

    ServerSocket serverSocket = null;
    InputStream inputStream = null;
    FileOutputStream fileOutputStream = null;
    try {
        serverSocket = new ServerSocket(portNumber);
        System.out.println("正在监听端口" + portNumber + "...");

        Socket clientSocket = serverSocket.accept();
        System.out.println("客户端已连接！");

        inputStream = clientSocket.getInputStream();
        fileOutputStream = new FileOutputStream("D:\\test\\received_file.txt");

        byte[] buffer = new byte[4096];
        int bytesRead;
        while ((bytesRead = inputStream.read(buffer)) != -1) {
            fileOutputStream.write(buffer, 0, bytesRead);
        }


    } catch (IOException e) {
        e.printStackTrace();
    }finally {
        fileOutputStream.close();
        inputStream.close();
        serverSocket.close();
        serverSocket.close();
    }
}