Truyền file bằng giao thức TCP/IP trong Java Swing – VietTuts

Bài này được nâng cấp và phát triển từ bài Ví dụ TCP/IP transfer file

Đây là một ví dụ về việc sử dụng giao thức TCP/IP để truyền file.

Tạo lớp vn.viettuts.common.FileInfo giống nhau cho cả phía client và server để gửi và nhận thông tin của một file thông qua đối tượng này.

Cấu trúc TCPServer project:

File: TCPServer.java

package vn.viettuts.server;
 
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
 
import vn.viettuts.common.FileInfo;
 
public class TCPServer extends Thread {
    // create serverSocket object
    private ServerSocket serverSocket;
    private int port = 9900;
 
    /**
     * run program
     * 
     * @author viettuts.vn
     * @param args
     */
    public static void main(String[] args) {
        TCPServer tcpServer = new TCPServer();
        tcpServer.open();
        tcpServer.start();
    }
 
    /**
     * open server
     * 
     * @author viettuts.vn
     */
    public void open() {
        try {
            serverSocket = new ServerSocket(port);
            System.out.println("server is open on port " + port);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
 
    /**
     * handle event
     * 
     * @author vietuts.vn
     */
    public void run() {
        while (true) {
            Socket server = null;
            DataInputStream inFromClient = null;
            ObjectInputStream ois = null;
            ObjectOutputStream oos = null;
            
            try {
                // accept connect from client and create Socket object
                server = serverSocket.accept();
                System.out.println("connected to "
                        + server.getRemoteSocketAddress());
 
                // get greeting from client
                inFromClient = new DataInputStream(server.getInputStream());
                System.out.println(inFromClient.readUTF());
 
                // receive file info
                ois = new ObjectInputStream(server.getInputStream());
                FileInfo fileInfo = (FileInfo) ois.readObject();
                if (fileInfo != null) {
                    createFile(fileInfo);
                }
 
                // confirm that file is received
                oos = new ObjectOutputStream(server.getOutputStream());
                fileInfo.setStatus("success");
                fileInfo.setDataBytes(null);
                oos.writeObject(fileInfo);
                 
            } catch (IOException e) {
                e.printStackTrace();
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            } finally {
                // close all stream
                closeStream(ois);
                closeStream(oos);
                closeStream(inFromClient);
                // close session
                closeSocket(server);
            }
        }
    }
 
    /**
     * create file with fileInfo
     * 
     * @author viettuts.vn
     * @param fileInfo
     * @return file is created or not
     */
    private boolean createFile(FileInfo fileInfo) {
        BufferedOutputStream bos = null;
        
        try {
            if (fileInfo != null) {
                File fileReceive = new File(fileInfo.getDestinationDirectory() 
                        + fileInfo.getFilename());
                bos = new BufferedOutputStream(
                        new FileOutputStream(fileReceive));
                // write file content
                bos.write(fileInfo.getDataBytes());
                bos.flush();
            }
        } catch (IOException e) {
            e.printStackTrace();
            return false;
        } finally {
            closeStream(bos);
        }
        return true;
    }
    
    /**
     * close socket
     * 
     * @author viettuts.vn
     */
    public void closeSocket(Socket socket) {
        try {
            if (socket != null) {
                socket.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * close input stream
     * 
     * @author viettuts.vn
     */
    public void closeStream(InputStream inputStream) {
        try {
            if (inputStream != null) {
                inputStream.close();
            }
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }

    /**
     * close output stream
     * 
     * @author viettuts.vn
     */
    public void closeStream(OutputStream outputStream) {
        try {
            if (outputStream != null) {
                outputStream.close();
            }
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }
}