Java Socket 模拟 Ftp Server/Client

 花了将近两天的时间实现了使用Java Socket 模拟了一个简单的Ftp Server/Client，主要实现了文件上载、下传、删除以及目录浏览等操作，由于时间关系只能后面继续完善，先做一记录。

1、直接上图：

1）Server端的展示图：

 

 

 

 

2）Client端的展示：

 

 

 

2、核心代码

1）、Server端的ServerSocket

 

public FtpServer()
	{
		loadServerInfo();

		int i = 0;
		try
		{
			ServerSocket s = new ServerSocket(Integer.parseInt(sInfo.getPort()));
			for(;;)
			{
				Socket incoming = s.accept();

			    FtpHandler h = new FtpHandler(incoming,i);
				h.start();
				i++;
			}
		}
		catch(Exception e)
		{
			e.printStackTrace();
		}

	}

 

 

2）Server端对接收到的客户请求的处理

 

public void run() // 监听客户端输入的指令
	{
		try {
			out = new DataOutputStream(csocket.getOutputStream()); // 给客户端返回的流
			DataInputStream in = new DataInputStream(csocket.getInputStream()); // 客户端发送来的信息
			cmd = in.readUTF();
			ServerUtil.outLogging(cmd);
			cmdArr = cmd.split(" ");
			if (cmdArr[0].equals("LINK"))
				loginServer();
			if (cmdArr[0].equals("DOWN"))
				sendFile();
			if(cmdArr[0].equals("UPDATE"))
				updateFile();
			if(cmdArr[0].equals("GETDIR"))
				sendCurrentDirList();
			if(cmdArr[0].equals("DELETE"))
				deleteFile();
			if(cmdArr[0].equals("DELETE"))
				deleteFile();
			
			csocket.close();
			this.stop();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

 

 

3）、客户端发送Socket的代码

 

public void run() {
		try {
			socket = new Socket(FtpClientJFrame.ip, FtpClientJFrame.port);

			in = new DataInputStream(socket.getInputStream()); // 服务器发送回来的消息
			out = new DataOutputStream(socket.getOutputStream()); // 发送给服务端的消息
			out.writeUTF(FtpClientJFrame.out);
			String rs = in.readUTF();
			if (rs == "LOGINOK" || rs.equals("LOGINOK")) {
				JOptionPane.showMessageDialog(null, "连接成功!", "提示",
						JOptionPane.INFORMATION_MESSAGE);
				FtpClientMain.cInfo.setCurrentServerPath(in.readUTF());
				FtpClientMain.cInfo.setLoginState(true);
				FtpClientMain.cInfo.setIpAdd(FtpClientJFrame.ip);
				FtpClientMain.cInfo.setPort(FtpClientJFrame.port);
				getDirList();
			} else if (rs == "LOGINNO" || rs.equals("LOGINNO")) {
				JOptionPane.showMessageDialog(null, "用户名或者密码错误!", "提示",
						JOptionPane.INFORMATION_MESSAGE);
			}
		} catch (UnknownHostException e) {
			JOptionPane.showMessageDialog(null, "未找到对应主机!", "提示",
					JOptionPane.INFORMATION_MESSAGE);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

 

3、Server/Client的状态信息

1）、Server

public class ServerInfo
{
	private String ipAdd;
	private String port;
	
	private String username;
	private String password;
	private String pathDir;
	private Boolean canUpdate;
	private Boolean canDelete;
	private Boolean canDownlaod;
	
	public Boolean getCanDelete() {
		return canDelete;
	}
	public void setCanDelete(Boolean canDelete) {
		this.canDelete = canDelete;
	}
	public Boolean getCanDownlaod() {
		return canDownlaod;
	}
	public void setCanDownlaod(Boolean canDownlaod) {
		this.canDownlaod = canDownlaod;
	}
	public Boolean getCanUpdate() {
		return canUpdate;
	}
	public void setCanUpdate(Boolean canUpdate) {
		this.canUpdate = canUpdate;
	}
	public String getIpAdd() {
		return ipAdd;
	}
	public void setIpAdd(String ipAdd) {
		this.ipAdd = ipAdd;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public String getPathDir() {
		return pathDir;
	}
	public void setPathDir(String pathDir) {
		this.pathDir = pathDir;
	}
	public String getPort() {
		return port;
	}
	public void setPort(String port) {
		this.port = port;
	}
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	
}

 2）、Client

 

public class ClientInfo {

	private String ipAdd;
	private int port;
	private Boolean loginState = false;
	private String localPath = "D:/FTPClient/";
	private String currentPath;
	private String currentServerPath;

	public String getIpAdd() {
		return ipAdd;
	}
	public void setIpAdd(String ipAdd) {
		this.ipAdd = ipAdd;
	}
	public int getPort() {
		return port;
	}
	public void setPort(int port) {
		this.port = port;
	}
	public Boolean getLoginState() {
		return loginState;
	}
	public void setLoginState(Boolean loginState) {
		this.loginState = loginState;
	}
	public String getLocalPath() {
		return localPath;
	}
	public void setLocalPath(String localPath) {
		this.localPath = localPath;
	}
	public String getCurrentPath() {
		currentPath = localPath;
		return currentPath;
	}
	public void setCurrentPath(String currentPath) {
		this.currentPath = currentPath;
	}
	public String getCurrentServerPath() {
		return currentServerPath;
	}
	public void setCurrentServerPath(String currentServerPath) {
		this.currentServerPath = currentServerPath;
	}

 

4、涉及到的问题

1）、对Stream的操作

（代码见附件）

2）、对FileInputStream、InputStream等的转换，附上从OutPutStream中回去并保存文件的代码。

// 从流中读取内容并保存  
        private void readAndSave(InputStream is) throws IOException {  
            String filename = getFileName(is);  
            int file_len = readInteger(is);  
            System.out.println("接收文件：" + filename + "，长度：" + file_len);  
   
            readAndSave0(is, savePath + filename, file_len);  
   
            System.out.println("文件保存成功（" + file_len + "字节）。");  
        }  
   
        private void readAndSave0(InputStream is, String path, int file_len) throws IOException {  
            FileOutputStream os = getFileOS(path);  
            readAndWrite(is, os, file_len);  
            os.close();  
        }  
   
        // 边读边写，直到读取 size 个字节  
        private void readAndWrite(InputStream is, FileOutputStream os, int size) throws IOException {  
            byte[] buffer = new byte[4096];  
            int count = 0;  
            while (count < size) {  
                int n = is.read(buffer);  
                // 这里没有考虑 n = -1 的情况  
                os.write(buffer, 0, n);  
                count += n;  
            }  
        }  
   
        // 读取文件名  
        private String getFileName(InputStream is) throws IOException {  
            int name_len = readInteger(is);  
            byte[] result = new byte[name_len];  
            is.read(result);  
            return new String(result);  
        }  
   
        // 读取一个数字  
        private int readInteger(InputStream is) throws IOException {  
            byte[] bytes = new byte[4];  
            is.read(bytes);  
            return b2i(bytes);  
        }  
   
        // 创建文件并返回输出流  
        private FileOutputStream getFileOS(String path) throws IOException {  
            File file = new File(path);  
            if (!file.exists()) {  
                file.createNewFile();  
            }  
   
            return new FileOutputStream(file);  
        } 

 3）、涉及到对文件（夹）等的操作

（见附件）

 

5、如何通过模拟的实现去理解Ftp的工作原理

（未完待续）

6、存在的问题

 

 

最后，欢迎拍砖。