使用java语言设计一个基于TCP的文件上传功能，将文件从客户端上传到指定服务器的可行程序。 并实现文件传输完成后服务器给客户端发送“文件上传成功”的信息。

以下是一个基于TCP协议的Java程序，实现了将文件从客户端上传到指定服务器的功能，并在文件传输完成后向客户端发送“文件上传成功”的信息。

服务端代码：

import java.io.*;
import java.net.*;

public class FileServer {
    public static void main(String[] args) throws IOException {
        ServerSocket serverSocket = null;
        try {
            serverSocket = new ServerSocket(9999);
        } catch (IOException e) {
            System.err.println("Could not listen on port: 9999.");
            System.exit(1);
        }

        Socket clientSocket = null;
        try {
            System.out.println("Waiting for client...");
            clientSocket = serverSocket.accept();
            System.out.println("Client connected: " + clientSocket.getInetAddress().getHostName());
        } catch (IOException e) {
            System.err.println("Accept failed.");
            System.exit(1);
        }

        InputStream in = clientSocket.getInputStream();
        OutputStream out = null;
        try {
            out = new FileOutputStream("server-file.txt");
        } catch (FileNotFoundException e) {
            System.err.println("File not found!");
            System.exit(1);
        }

        byte[] bytes = new byte[1024];
        int count;
        while ((count = in.read(bytes)) > 0) {
            out.write(bytes, 0, count);
        }

        out.close();
        in.close();
        clientSocket.close();
        serverSocket.close();

        PrintWriter pw = new PrintWriter(clientSocket.getOutputStream(), true);
        pw.println("File uploaded successfully!");

        System.out.println("File uploaded successfully!");
    }
}

客户端代码：

import java.io.*;
import java.net.*;

public class FileClient {
    public static void main(String[] args) throws IOException {
        Socket socket = null;
        try {
            socket = new Socket("localhost", 9999);
            System.out.println("Connected to server: " + socket.getInetAddress().getHostName());
        } catch (UnknownHostException e) {
            System.err.println("Don't know about host: localhost.");
            System.exit(1);
        } catch (IOException e) {
            System.err.println("Couldn't get I/O for the connection to: localhost.");
            System.exit(1);
        }

        File file = new File("client-file.txt");
        FileInputStream in = null;
        try {
            in = new FileInputStream(file);
        } catch (FileNotFoundException e) {
            System.err.println("File not found!");
            System.exit(1);
        }

        OutputStream out = socket.getOutputStream();
        byte[] bytes = new byte[1024];
        int count;
        while ((count = in.read(bytes)) > 0) {
            out.write(bytes, 0, count);
        }

        out.close();
        in.close();
        socket.close();

        BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        String message = br.readLine();
        System.out.println("Message from server: " + message);
    }
}

在客户端和服务端的代码中，文件名和端口号可以根据具体需求进行修改。