Java使用TCP和UDP传输文件的源代码

import java.net.*; import java.io.*; /** * UDPSender is an implementation of the Sender interface, using UDP as the transport protocol. * The object is bound to a specified receiver host and port when created, and is able to * send the contents of a file to this receiver. * * @author Alex Andersen (alex@daimi.au.dk) */ public class TCPSender implements Sender{ private File theFile; private FileInputStream fileReader; private Socket s; private int fileLength, currentPos, bytesRead, toPort, length; private byte[] msg, buffer; private String toHost,initReply; private InetAddress toAddress; private OutputStream theOutstream; private InputStream theInstream; /** * Class constructor. * Creates a new UDPSender object capable of sending a file to the specified address and port. * * @param address the address of the receiving host * @param port the listening port on the receiving host */ public TCPSender(InetAddress address, int port) throws IOException{ toPort = port; toAddress = address; msg = new byte[8192]; buffer = new byte[8192]; s = new Socket(toAddress, toPort); theOutstream = s.getOutputStream(); theInstream = s.getInputStream(); } /** * Sends a file to the bound host. * Reads the contents of the specified file, and sends it via UDP to the host * and port specified at when the object was created. * * @param theFile the file to send */ public void sendFile(File theFile) throws IOException{ // Init stuff fileReader = new FileInputStream(theFile); fileLength = fileReader.available(); System.out.println(" -- Filename: "+theFile.getName()); System.out.println(" -- Bytes to send: "+fileLength); // 1. Send the filename and length to the receiver theOutstream.write((theFile.getName()+"::"+fileLength).getBytes()); theOutstream.flush(); // 2. Wait for a reply from the receiver System.out.println(" -- Waiting for OK from the receiver"); length = 0; while (length <= 0){ length = theInstream.read(buffer); if (length>0) initReply = (new String(buffer, 0, length)); } // 3. Send the content of the file if (initReply.equals("OK")) { System.out.println(" -- Got OK from receiver - sending the file "); while (currentPos<fileLength){ //System.out.println("Will read at pos: "+currentPos); bytesRead = fileReader.read(msg); theOutstream.write(msg); //System.out.println("Bytes read: "+bytesRead); currentPos = currentPos + bytesRead; } System.out.println(" -- File transfer complete..."); } else{System.out.println(" -- Recieved something other than OK... exiting");} } }