tcp文件的传送

tcp是一个有连接的可靠的连接

服务器端：主要是建议一个等待连接的端口，等待客户机的连接，等待线程，用户之后，获取输入流，输出流，然后利用输入流输出流进行传送文件。

传送文件时候，因为文件比较大，所以需要分为多次传送。传送的次序，首先传送文件的名字，文件的长度，然后分多次传送文件的内容。

ZFile

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

public class ZFile extends File {

	public ZFile(String parent, String child) {
		super(parent, child);
		// TODO Auto-generated constructor stub
	}

	public ZFile(String pathname) {
		super(pathname);
		// TODO Auto-generated constructor stub
	}

	public ZFile(File parent, String child) {
		super(parent, child);
		// TODO Auto-generated constructor stub
	}

	public void sendFile(Socket connectionSocket) throws Exception {
		DataOutputStream outputStream = new DataOutputStream(connectionSocket
				.getOutputStream()); // 获取socket的输出流
		FileInputStream input = new FileInputStream(this.getName());// 获取文件的输入流 
		int bufsize = 1024;
		byte[] buf = new byte[bufsize + 1];// 读入缓存
		outputStream.writeBytes(this.getName()+"\n");// 传送文件名  读取时候需要读取一行
		outputStream.writeBytes("Filelen " + this.length() + "\n");// 传送文件长度 传输字符串 读取时候需要读取一行
		long filelen = this.length();
		System.out.println(filelen);
		long count = 0;
		/*大文件分为多次读取，每次读取1024，最后一次不足1024全部读取*/
		while (count < filelen) {
			long pre = count;
			if (filelen - pre > bufsize) {
				count += input.read(buf, 0, bufsize);
				outputStream.write(buf, 0, bufsize);
			} else {
				count += input.read(buf, 0, (int) (filelen - pre));
				outputStream.write(buf, 0, (int) (filelen - pre));
			}
		}
		input.close();
		outputStream.close();
	}
}

服务器：

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

class TCPServer {
	public static void main(String argv[]) throws Exception {
		String ClientSentence;
		@SuppressWarnings("unused")
		String capitalizedSentence;
		ServerSocket welcomeSocket = new ServerSocket(6669); // 建立tcp的等待端口
		while (true) {
			Socket connectionSocket = welcomeSocket.accept(); // tcp建立连接
			try {
				System.out.println("build ");
				BufferedReader infromClient = new BufferedReader(
						new InputStreamReader(connectionSocket.getInputStream())); // tcp的传输流
				// 输入流读入流
				DataOutputStream outToClient = new DataOutputStream(
						connectionSocket.getOutputStream()); // tcp的输出流 写流
				System.out.println("establish");
				ClientSentence = infromClient.readLine(); // 读取一行 遇到换行停止
				System.out.println(ClientSentence);
				String filename = "in.pdf";
				ZFile sendFile = new ZFile("in.pdf");
				sendFile.sendFile(connectionSocket);
				FileInputStream input = new FileInputStream(sendFile);
				outToClient.close();
				infromClient.close();
				connectionSocket.close();
			} catch (Exception e) {
				connectionSocket.close();
			}
		}
	}

}

客户端

客户端一上来需要与服务器进行连接，接着获取输入流，输出流，然后紧接着利用输入流获取文件名，获取文件的长度，然后很多次获取文件内容

import java.io.*;
import java.net.*;
class TCPClient{
  public static void main(String argv[]) throws Exception
  {
     String sentence;
     String modifiedSentence;
     BufferedReader infromUser =
        new BufferedReader(
              new InputStreamReader(System.in));
     Socket clientSocket = new Socket("127.0.0.1",6669);
     try{
     DataOutputStream outToServer =
        new DataOutputStream(
               clientSocket.getOutputStream());
     BufferedReader infromServer =
        new BufferedReader(new InputStreamReader(
               clientSocket.getInputStream()));
     DataInputStream dataInput = new DataInputStream(clientSocket.getInputStream());
     sentence = infromUser.readLine();
     outToServer.writeBytes(sentence + '\n');
     String rec ;
     rec =infromServer.readLine();
     String filename = rec;
     System.out.println(rec);
     rec = infromServer.readLine();
     int fileLen = Integer.parseInt(rec.substring(8));
     FileOutputStream fileWrite = new FileOutputStream(filename);
     System.out.println(fileLen);
     int bufsize = 1024;
     byte[] buf = new byte[bufsize +1];
     int n = -1;
     int count = 0;
     while(count<fileLen)
     {
    	 int pre = count;
    	 if(fileLen - pre > bufsize)
    	 {
    		 count += bufsize;
    		 dataInput.read(buf, 0,bufsize);
    		 fileWrite.write(buf,0,bufsize);
    		 System.out.println(new String(buf,0,bufsize));
    	 }
    	 else
    	 {
    		 count += dataInput.read(buf, 0,fileLen-pre);
    		 count = fileLen;
    		 fileWrite.write(buf,0,fileLen-pre);
    		 System.out.println(new String(buf,0,fileLen - pre));
    	 }
    	
    }
     clientSocket.close();
     }
     catch(Exception e)
     {
         clientSocket.close();
     }
   }
}