dirthread.java

来自「java编程开发技巧与实例的编译测试通过的所有例程」· Java 代码 · 共 118 行

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

public class DirThread extends Thread
{
	private ObjectOutputStream	out		=	null;
	private DataInputStream		in		=	null;
	private Socket 				sock	=	null;
	private boolean 			running	=	false;
	private File currentPath	=	new File(System.getProperty("user.dir"));
	public DirThread(Socket _sock)
	{
		System.out.println("Start directory connection . . . ");
		sock = _sock;
		try
		{
			in	=	new DataInputStream(sock.getInputStream());
			out	=	new ObjectOutputStream(sock.getOutputStream());
			running	=	true;
			start();
		}
		catch	(IOException ioe)
		{
			System.err.println("Error setting up streams: " + ioe);
		}
	}
	public void run()
	{
		authenticate();
		while	(running)
		{
			try
			{
				processCommand(in.readUTF(),in.readUTF());
			}
			catch	(IOException ioe)
			{
				hangup();
			}
		}
	}
	private void send(File list[]) throws IOException
	{
		FileInfo info[]	=	new FileInfo[list.length];
		for (int i = 0; i < list.length; i ++)
			info[i]	=	new FileInfo(list[i]);
		out.writeObject(list);
		out.flush();
	}
	private void send(String msg) throws IOException
	{
		out.writeUTF(msg);
		out.flush();
	}
	private void changeDirectory(String newDir) throws IOException
	{
		if ((newDir.equals("..")) &&
			(currentPath.getParentFile() != null))
			currentPath = currentPath.getParentFile();
		else
		{
			File newPath = new File(newDir);
			if (newPath.exists() && newPath.isDirectory())
				currentPath = newPath;
		}
		send(currentPath.toString());
	}
	private void authenticate()
	{
		try
		{
			String cmd	=	in.readUTF();
			String passwd	=	in.readUTF();
			if (passwd.equals(DirServer.VERSION + "|" + DirServer.PASSWD))
				send("okay");
			else
			{
				send("error");
				hangup();
			}
		}
		catch	(IOException ioe)
		{
			hangup();
		}
	}
	private void hangup()
	{
		try
		{
			System.out.println("Hanging up");
			in.close();
			out.close();
			sock.close();
		}
		catch	(IOException ioe)
		{
			System.err.println("Error disconnecting: " + ioe);
		}
		finally
		{
			running = false;
		}
	}
	private void processCommand(String cmd, String option) throws IOException
	{
		if (cmd.equals("pwd"))
			send(currentPath.toString());
		else if (cmd.equals("chdir"))
			changeDirectory(option);
		else if (cmd.equals("list"))
			send(currentPath.listFiles());
		else
			hangup();
	}
}