ftpdhandler.java

java应用开发详解

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

public class FtpdHandler extends Thread 
{

	Socket socket;
	Socket dataSocket;
	ServerSocket serverSocketData;
	BufferedReader in;
	PrintWriter out; 
	File dir;
	boolean passiveMode=false;
	String dataType="I";	
	File target= new File("");

	public FtpdHandler(Socket s, String rootdir) 
	{ 
		socket = s;
		File temp = new File(rootdir);
		if (temp.isDirectory()) dir = temp;
		else return;
		start();
	}


	public void run() {  
		int port = 1;
		String user="";
		String host="";
		
 		InetAddress inet;
		
		try {
			//determine hostname

			inet = socket.getInetAddress();
			host = inet.getHostName();
			System.out.println(host+" connected");
			
			in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
			out = new PrintWriter(socket.getOutputStream(),true);

			out.println("220 SOOT2-Ftpd Ready");
			
			
			//登陆标识，注意本代码片没有进行密码验证
			boolean login = false;
			while (!login) 
			{
				try 
				{
					String str = in.readLine();
					StringTokenizer token = new StringTokenizer(str);
					String command = token.nextToken();
					
					if(command.equals("USER"))
					{
                        			user = token.nextToken();
                        			//提示输入密码
						out.println("331 Password");
					}
					else if(command.equals("PASS")) 
					{
						//提示登陆成功
						out.println("230 User "+user+" logged in.");
						login = true;
					}
					else out.println("530 Not logged in.");
				}
				catch(NoSuchElementException e) 
				{
					out.println("500 syntax error dude.");
				}
			}
			
			while(true) 
			{
				try 
				{	
				//Read command
				String str = in.readLine();
				StringTokenizer token = new StringTokenizer(str);
				String command = token.nextToken();

				//if command is RETR (==download)

				//从服务器下载文件
				if(command.equals("RETR")) 
				{
					//得到文件名
					String filename = token.nextToken();

					//只读方式打开文件
					RandomAccessFile outFile = new RandomAccessFile(dir.getPath()+"/"+filename,"r");

					//判断是主动模式还是被动模式
					if (!passiveMode) 
					{
						//主动模式主动建立连接
						dataSocket = new Socket(inet,port);
					} 
					else 
					{
						
						//本例主要实现被动模式
						passiveMode=false;
					}
					
					int amount;
					try 
					{
						//二进制的形式
						if (dataType.equals("I")) 
						{
							out.println("150 Binary data connection.");
							OutputStream out2 = dataSocket.getOutputStream();
							//以字节流的形式读写
							byte bb[] = new byte[1024];
							while((amount = outFile.read(bb)) != -1) 
							{
								out2.write(bb, 0, amount);
							}
							out2.close();
						}
						//ascii码形式
						else if (dataType.equals("A")) 
						{
							out.println("150 ASCII data."); 
							PrintWriter out2 = new PrintWriter(dataSocket.getOutputStream());
							//以字符流的形式读写
							String line = outFile.readLine();
							while(line != null) 
							{
								out2.println(line);
								line = outFile.readLine();
							}
							out2.close();
						}
						out.println("226 transfer complete");
						outFile.close();
						dataSocket.close();
						
					}
					catch(IOException e8) 
					{
						out.println("426 Connection closed; transfer aborted.");
						try 
						{
						outFile.close();
						dataSocket.close();
						}
						catch(Exception e9) {}
					} 
				}

				
				//if command equals STOR (==upload)

				//将客户端提交的文件写入服务器
				else if(command.equals("STOR")) 
				{
					String filename = token.nextToken();
					
                        		//以读写方式打开文件
					RandomAccessFile inFile = new RandomAccessFile(dir.getPath()+"/"+filename,"rw");
					if (!passiveMode) 
					{
						dataSocket = new Socket(inet,port);
					} 
					else 
					{
						passiveMode=false;
					}
					int amount;
					try 
					{
						if (dataType.equals("I")) 
						{
							out.println("150 Binary data connection.");
							InputStream in2 = dataSocket.getInputStream();
							byte bb[] = new byte[1024];
							while((amount = in2.read(bb)) != -1) 
							{
								inFile.write(bb, 0, amount);
							}
							in2.close();
						}
						else if (dataType.equals("A")) 
						{
							out.println("150 ASCII data."); 
							BufferedReader in2 = new BufferedReader(new InputStreamReader(dataSocket.getInputStream()));
							String line = in2.readLine();
							while(line != null) 
							{
								inFile.writeBytes(line);
								line = in2.readLine();
							}
							in2.close();
						}
						out.println("226 transfer complete");
						inFile.close();
						dataSocket.close();
					}
					catch(IOException e6) 
					{
						out.println("426 Connection closed; transfer aborted.");
						try 
						{
							inFile.close();
							dataSocket.close();
						}
						catch(Exception e7) {}
					} 
				}

				else if(command.equals("TYPE")) 
				{
					String tp = token.nextToken();
					if (tp.equals("A") || tp.equals("I")) 
					{
						out.println("200 type set to "+tp);
						//设置数据类型
						dataType = tp;
					}
					else out.println("500 what type?");
				}

				else if(command.equals("DELE")) 
				{
					String filename = token.nextToken();
					File f = new File(dir,filename);
					f.delete();
					out.println("250 delete command successful");
				}

				else if(command.equals("CDUP")) 
				{
					File temp = dir.getParentFile();
					if (temp != null) dir = temp;
					out.println("250 CWD command succesful.");
				}

				else if(command.equals("CWD")) 
				{
					String newdir = token.nextToken();
					if (newdir.equals("..")) 
					{
						File temp = dir.getParentFile();
						if (temp != null) dir = temp;
						out.println("250 CWD command succesful");
					}
					else 
					{
						//搜索是否有该目录
						File temp = new File(dir.getPath() + "/" + newdir);
						File temp2 = new File(newdir);
						if (temp.isDirectory()) 
						{
							dir = temp;
							out.println("250 CWD command succesful");
						}
						else if (temp2.isDirectory()) {
							dir = temp2;
							out.println("250 CWD command succesful");
						}
						else out.println("550 No can do, directory doesn`t exist.");
					}
				}

				else if(command.equals("QUIT")) 
				{
					out.println("221 Have a nice day");
					System.out.println(host+" connection closed");
					break;
				}

				else if(command.equals("PWD")) 
				{
					out.println("257 \""+dir.getPath()+"\" is current directory");
				}
			
				else if(command.equals("SYST")) 
				{ 
					out.println("215 UNIX .");
				}

				else if(command.equals("PASV")) 
				{ 
					StringTokenizer token2 = new StringTokenizer(socket.getLocalAddress().getHostAddress());
					String[] parts = new String[4];
					for (int i=0;i<3;i++) 
					{
						parts[i]=token2.nextToken(".");
					}
					//最后一个IP段没有点分隔符
					parts[3]=token2.nextToken();
					out.println("227 Entering Passive Mode ("+parts[0]+","+parts[1]+","+parts[2]+","+parts[3]+",7,228)");
					//在2020开启一个监听端口
					serverSocketData= new ServerSocket(2020);
					dataSocket=serverSocketData.accept();
					//有连接请求后返回socket，并关闭监听服务
					serverSocketData.close();
					//设置被动模式
					passiveMode=true;					
				}

				else if(command.equals("PORT")) 
				{

					token.nextToken(",");
					token.nextToken();
					token.nextToken();
					token.nextToken();
					
					int res = 0;
					while (token.hasMoreTokens()) 
					{
						String a = token.nextToken();
						res = res * 256;
						res += Integer.parseInt(a);	
					}
					port = res;                  
					out.println("200 PORT command successful."); 
				}
				
				//得到服务器FTP目录的文件列表
				else if(command.equals("LIST")) 
				{
					if (!passiveMode) 
					{
						dataSocket = new Socket(inet,port);
					} else 
					{
						passiveMode=false;
					}
					PrintWriter out2 = new PrintWriter(dataSocket.getOutputStream(),true);
					try 
					{
						out.println("150 ASCII data."); 

						//打印当前目录的所以文件
						File[] a = dir.listFiles();
						out2.println("total "+a.length);
						for(int i = 0 ; i < a.length ; i++ ) 
						{
							if (a[i].isDirectory()) out2.println("dr-------- "+a[i].getName());
							else out2.println("-r-------- "+a[i].getName());
						}
						out2.close();
						dataSocket.close();
						out.println("226 transfer complete");
					}
					catch(IOException e) 
					{
						out.println("426 Connection closed; transfer aborted.");
						try 
						{
							out2.close();
							dataSocket.close();
						}
						catch(Exception e) {}
					} 
				}
				else if(command.equals("MKD")) 
				{
					String newdir = token.nextToken();
					
					//建立一个目录
					File temp = new File(newdir);
					if (!temp.isAbsolute()) temp = new File(dir,newdir);
					//建立成功
					if(temp.mkdir()) out.println("257 "+newdir+" created.");
					else out.println("550 directory not created.");
				}
				else if(command.equals("RMD")) 
				{
					String newdir = token.nextToken();
					File temp = new File(newdir);
					if (!temp.isAbsolute()) temp = new File(dir,newdir);
					//删除相应目录
					if(temp.delete()) out.println("257 "+newdir+" deleted.");
					else out.println("550 directory not deleted.");
				}
				else if(command.equals("RNFR")) 
				{
					String tname = token.nextToken();
					target = new File(tname);
					//判断文件是否存在
					if (!target.isAbsolute()) target = new File (dir,tname);
					if (target.exists()) out.println("350 File exists.");
					else out.println("550 No such file.");
				}
				else if(command.equals("RNTO")) 
				{
					String tname = token.nextToken();
					File temp = new File(tname);
					if (!temp.isAbsolute()) temp = new File(dir,tname);
					//将文件改名
					if (target.renameTo(temp)) out.println("250 File renamed.");
					else out.println("550 No can do.");
				}
				else 
				{
					out.println("500 Command not understood.");
				}
			} 
			
			catch(Exception e) 
			{
				out.println("500 error");
			}

			} 
			socket.close();
		
        
		} 
        	catch (Exception e3) 
        	{
			try 
			{
				socket.close();
			}
			catch(Exception e2) {}	
		} 
	} 
	
}