response.java

一个用JAVA做的FTP服务

package FtpServer;

import java.net.Socket;
import java.io.OutputStream;
import java.io.InputStream;
import java.io.IOException;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.File;

public class Response {
  	OutputStream output;
  	Request request;
  	File workingDir;
	public static final int WELCOME = 101;		//send welcome message
	public static final int GET_PSW  = 102;		//get psw
	public static final int LOGIN_SUCC = 103;	//login succ
	public static final int PSW_ERROR = 104;	//psw error , login fail
	public static final int ERROR_CMD = 105;	//error command
	
	public static final int ERROR = -1;


  	public Response(OutputStream output) {
    	this.output = output;
  	}
  	public void setRequest(Request rq) {
  		request = rq;
  	}
  	public void setWorkingDir(String wd) {
  		workingDir = new File(wd);
  	}

	public boolean sendEventMsg(int evt) throws IOException {
		try {
			switch(evt) {
				case WELCOME : 
					sendMsg("220 My FTP Server ready ...");
					break;
				case GET_PSW : 	
					sendMsg("331 Password required for " + request.getUser());
					break;
				case LOGIN_SUCC :
					sendMsg("230 User " + request.getUser() + " logged in.");
					break;
				case PSW_ERROR :
					sendMsg("530 Login or Password incorrect.");
					break;
				case ERROR_CMD :	
					sendMsg("221 command error. disconnect");
					break;
				case Request.SYSTEM :
					sendMsg("215 UNIX Type: L8");
					break;
				case Request.RETRIEVE:	
					sendMsg("150 Opening data connection for " + request.getFilename());
					sendFile();
					break;
				case Request.STORE:	
					sendMsg("150 Opening data connection for " + request.getFilename());
					receiveFile();
					break;
				case Request.PRINT_WORKING_DIRECTORY:
					sendMsg("257 \"" + getDir() + "\" is current directory.");
					break;
				case Request.LIST:
					sendMsg("150 Opening data connection for directory list.");
					sendDirMsg();
					sendMsg("226 File sent ok.");
					break;
				case Request.NOOP:
					sendMsg("200 NOOP command successful.");
					break;
				case Request.LOGOUT:
					//sendMsg("221 Bye Bye ...");
					break;
				case Request.CURRENT_WORKING_DIRECTORY:
					changeDir();
					sendMsg("250 CWD command successful. \"" + getDir() + "\" is current directory");
					break;
				case Request.DATA_PORT:
					sendMsg("200 Port command successful..");
					break;
				case Request.CHANGE_DIR_UP:
					changeUpDir();
					sendMsg("250 CWD command successful. " + getDir() + " is current directory.");
					break;
				default :
					sendMsg("500 '" + request.getRequestCmd() + "': command not understood.");
					break;
			}
			return true;
		}
		catch (Exception e) {
			System.out.println(e.toString() );
			return false;
		}
	}

	//send response message
  	public void sendMsg(String sendMsg) throws IOException {
  		byte[] buf =new byte[2];
  		buf[0] = 13;
  		buf[1] = 10;
	    try {
			output.write(sendMsg.getBytes(), 0, sendMsg.length());
			output.write(buf, 0, 2);
			System.out.println(sendMsg);
		}
    	catch (Exception e) {
      		// thrown if cannot instantiate a File object
      		System.out.println(e.toString() );
    	}
  	}
  	
  	// change working directory
  	private void changeDir()
  	{
  		String curDir = request.getFilename();
  		if (curDir.charAt(0) == '/') {
				curDir = curDir.replace('/','\\' ) ;
				System.out.println(curDir);
				if (curDir.charAt(curDir.length()-1) == '\\' && curDir.length() > 1)
					curDir = curDir.substring(0,curDir.length()-1);
				workingDir = new File(FtpServer.rootDir + curDir);
  		}
  		else {
  			workingDir = new File(workingDir.getPath() + File.separator + curDir);
  		}  		
  	}
  	
  	// change the upper directory
  	private void changeUpDir() {
  		String curDir = workingDir.getPath();
		if (curDir.charAt(curDir.length()-1) == '\\' && curDir.length() > 1)
			curDir = curDir.substring(0,curDir.length()-1);
  		int index = curDir.length();
  		int tmpIndex=0;
  		while ((tmpIndex = curDir.indexOf('\\',tmpIndex+1))>0) index = tmpIndex;
  		curDir  = curDir.substring(0,index);
		System.out.println(curDir );
  		workingDir = new File(curDir);
  	}
  	
  	// get the current working directory
  	private String getDir() {
  		String curDir = workingDir.getPath();
  		String relativeDir = curDir.substring(FtpServer.rootDir.length(),curDir.length());
  		relativeDir =  relativeDir + File.separator;
  		relativeDir = relativeDir.replace('\\','/');
  		return relativeDir;
  	}
  	
  	// list files in the working directory
  	private void sendDirMsg() throws IOException {
  		try {
	  		Socket socket;
			socket = new Socket(request.getIP(), request.getPort());
			
			OutputStream output = socket.getOutputStream();
			String dirMsg = new String();
			
			File[] fileList = workingDir.listFiles();
			for(int i=0; i<fileList.length; i++) {
				String msg = "";
				if ( fileList[i].isDirectory() )msg = "drwxr-xr-x   1 ftp      ftp            0";
				else {
					msg = "-rw-r--r--   1 ftp      ftp";
					String fileSize = String.valueOf(fileList[i].length());
					for(int j=0; j<	22 - fileSize.length(); j++)
						fileSize = " " + fileSize;
					msg +=	fileSize;
				}
				msg += " Nov 04 18:15 ";
				msg += fileList[i].getName();
				msg += "\r\n";
				dirMsg += msg;
			}
			if (fileList.length == 0) dirMsg = "\r\n";
			output.write(dirMsg.getBytes(),0,dirMsg.length());
			System.out.println(dirMsg);
			socket.close();
		}catch(Exception e)
		{
      		System.out.println(e.toString() );
		}
  	}

	// send file
  	private void sendFile() throws IOException {
  		int BUFFER_SIZE = 1024;
  		try {
	  		Socket socket;
			socket = new Socket(request.getIP(), request.getPort());
			
			OutputStream output = socket.getOutputStream();
						
		    byte[] bytes = new byte[BUFFER_SIZE];
		    FileInputStream fis = null;
		    try {
	      		File file = new File(workingDir.getPath(), request.getFilename());
	      		if (file.exists()) {
	        		fis = new FileInputStream(file);
	        		int ch = fis.read(bytes, 0, BUFFER_SIZE);
	        		while (ch!=-1) {
	          			output.write(bytes, 0, ch);
	          			ch = fis.read(bytes, 0, BUFFER_SIZE);
	        		}
					sendMsg("226 File sent ok.");
	      		}
	      		else {
	        		// file not found
	        		sendMsg("550 cannot open File: " + request.getFilename() + " : No Such File.");
	      		}
	    	}
	    	catch (Exception e) {
	      		// thrown if cannot instantiate a File object
	      		System.out.println(e.toString() );
	    	}
	    	finally {
	      		if (fis!=null)
	        	fis.close();
	    	}
	    	socket.close();
		}catch(Exception e)
		{
      		System.out.println(e.toString() );
		}
  	}

  	//receive file to current working directory
  	private void receiveFile() throws IOException {
  		int BUFFER_SIZE = 1024;
  		try {
	  		Socket socket;
			socket = new Socket(request.getIP(), request.getPort());
			
			InputStream input = socket.getInputStream();
						
		    byte[] bytes = new byte[BUFFER_SIZE];
		    FileOutputStream fos = null;
		    try {
	      		File file = new File(workingDir.getPath(), request.getFilename());
	      		if (file.createNewFile()) {
	        		fos = new FileOutputStream(file);
	        		
	        		
	        		int ch = input.read(bytes, 0, BUFFER_SIZE);
	        		while (ch!=-1) {
	          			fos.write(bytes, 0, ch);
	          			ch = input.read(bytes, 0, BUFFER_SIZE);
	        		}
					sendMsg("226 File received ok.");
	      		}
	      		else {
	        		// file can't write
	        		sendMsg("550 cannot upload File:" + request.getFilename());
	      		}
	    	}
	    	catch (Exception e) {
	      		// thrown if cannot instantiate a File object
	      		System.out.println(e.toString() );
	    	}
	    	finally {
	      		if (fos!=null)
	        	fos.close();
	    	}
	    	socket.close();
		}catch(Exception e)
		{
      		System.out.println(e.toString() );
		}
  	}
}