thread_ftp.java

支持多线程的ftp下载源程序,没有用任何第三方组件

package ext.down;

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

public class Thread_ftp extends Thread
{
	long nStartPos;

	long nEndPos;

	String sFile_url;

	final int PORT = 21;

	Socket Get_data_socket = null;

	Socket Get_info_socket = null;

	DataInputStream get_data = null;

	boolean is_Down = false;

	boolean is_Stop = false;

	String sUser;

	String sPwd;

	String sInfo;

	String sSave_file;

	String sDown_file;

	String threadID;

	FileAccess fileaccess = null;

	private boolean VERBOSE = false;

	public Thread_ftp(long number_1, long number_2, String s1, String s2,
			String s3, String s4, String s5, int i) throws IOException
	{
		nStartPos = number_1;
		nEndPos = number_2;
		sFile_url = s1;
		sUser = s2;
		sPwd = s3;
		sSave_file = s4;
		sDown_file = s5;
		this.threadID = "第" + (i + 1) + "线程";
		fileaccess = new FileAccess(this.sSave_file, this.nStartPos);
	}

	public void run()
	{
		while (this.nStartPos < this.nEndPos && this.nStartPos != -1)
		{
			try
			{
				this.Get_info_socket = new Socket(this.sFile_url, this.PORT);
				PrintWriter put_info = new PrintWriter(this.Get_info_socket
						.getOutputStream(), true);
				BufferedReader get_info = new BufferedReader(
						new InputStreamReader(this.Get_info_socket
								.getInputStream()));
				put_info.println("USER " + this.sUser);
				this.getInfo(get_info);
				put_info.println("PASS " + this.sPwd);
				this.getInfo(get_info);
				put_info.println("TYPE I");
				this.getInfo(get_info);
				put_info.println("PASV");
				this.getInfo(get_info);
				sInfo = get_info.readLine();
				if (VERBOSE)
					System.out.println(sInfo + "OK");
				put_info.println("REST " + this.nStartPos);
				this.getInfo(get_info);
				this.Get_data_socket = new Socket(this.get_info_ip(this.sInfo,
						0), Integer.parseInt(this.get_info_ip(this.sInfo, 1)));
				put_info.println("RETR " + this.sDown_file);
				this.getInfo(get_info);
				this.Get_info_socket.close();
				this.get_data = new DataInputStream(this.Get_data_socket
						.getInputStream());

				byte[] b = new byte[1024];
				int nRead;
				while ((nRead = this.get_data.read(b, 0, 1024)) > 0
						&& this.nStartPos < this.nEndPos
						&& this.nStartPos != -1)
				{
					this.nStartPos += this.fileaccess.write(b, 0, nRead);

					if (VERBOSE)
						System.out
								.println("写入" + nRead + "字节到" + this.threadID);
				}
				this.is_Down = true;
				this.is_Stop = true;

			}
			catch (UnknownHostException e)
			{
				this.is_Stop = true;
				System.out.println("意外的错误3：未知的主机" + e.toString());
			}
			catch (IOException e2)
			{
				this.is_Stop = true;
				System.out.println("意外的错误4：输入输出错误" + e2.toString());
			}
		}
		System.out.println(this.threadID + "结束");
	}

	public boolean getInfo(BufferedReader buffer)
	{
		boolean more = true;
		boolean is_OK = false;
		String s;

		try
		{
			while (more)
			{
				s = buffer.readLine();
				if (s.length() == 0)
				{
					s = buffer.readLine();
				}
				// if (VERBOSE)
				System.out.println(s);
				if (String.valueOf(s.charAt(3)).equals(" "))
				{
					more = false;
					is_OK = true;
				}
			}
		}
		catch (IOException e)
		{
			is_OK = false;
		}
		return is_OK;
	}

	public String get_info_ip(String string, int i)
	{
		int number_1;
		int number_2;
		int number_3;
		int number_4;
		int number_5;
		int number_6;
		int number_7;
		int port_1;
		int port_2;
		String port;

		number_1 = string.indexOf("(");
		number_2 = string.indexOf(",");
		number_3 = string.indexOf(",", number_2 + 1);
		number_4 = string.indexOf(",", number_3 + 1);
		number_5 = string.indexOf(",", number_4 + 1);
		number_6 = string.indexOf(",", number_5 + 1);
		number_7 = string.indexOf(")", number_6 + 1);
		String first_ip = string.substring(number_1 + 1, number_2);
		String second_ip = string.substring(number_2 + 1, number_3);
		String third_ip = string.substring(number_3 + 1, number_4);
		String forth_ip = string.substring(number_4 + 1, number_5);
		port_1 = Integer.parseInt(string.substring(number_5 + 1, number_6));
		port_2 = Integer.parseInt(string.substring(number_6 + 1, number_7));
		port = String.valueOf((port_1 << 8) + port_2);

		if (i == 0)
		{
			return first_ip + "." + second_ip + "." + third_ip + "." + forth_ip;
		}
		else
		{
			if (i == 1)
			{
				return port;
			}
			else
			{
				return "";
			}
		}

	}
}