signatureserver.java

一个JAVA小程序！功能不小！

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.net.Socket;
import java.net.ServerSocket;

public class SignatureServer {

  private int port = 1923;

  private ServerSocket serverSocket;

  class ServerThread implements Runnable {
    private Socket socket;
    private DataInputStream datain;
    private DataOutputStream dataout;

    public ServerThread(Socket socket) {
      this.socket = socket;
    }

    public void run() {
      try {
        datain = new DataInputStream(new BufferedInputStream
          (socket.getInputStream()));
        dataout = new DataOutputStream(new BufferedOutputStream
          (socket.getOutputStream()));
      }
      catch (IOException e) {
        return;
      }
      byte[] ba = new byte[6];
      boolean conversationActive = true;
      while(conversationActive) {
        String name = null;
        try {
          datain.read(ba,0,6);
          name = new String(ba);
          if (name.toUpperCase().charAt(0) == '$') {
            conversationActive = false;
          }
          else {
            System.out.println("verifying signature for = " + name);
            byte[] ia = getImage("ptremblett.png");
            String sl = Integer.toString(ia.length) + "\n";
System.out.println("sending length = " + sl);
            dataout.write(sl.getBytes(),0,sl.length());
            dataout.flush();
System.out.println("sending " + ia.length + " bytes");
            dataout.write(ia,0,ia.length);
            dataout.flush();
System.out.println("signature sent");
          }
        }
        catch (IOException ioe) {
          conversationActive = false;
        }
      }
      try {
        System.out.println("closing socket");
        datain.close();
        dataout.close();
        socket.close();
      }
      catch (IOException e) {
      }
    }

    private byte[] getImage(String fname) {
      byte[] ba = new byte[0];
      try {
        File f = new File(fname);
        ba = new byte[(int)f.length()];
        BufferedInputStream bis = 
          new BufferedInputStream(new FileInputStream(f));
        int nb = bis.read(ba,0,ba.length);
System.out.println("nb = " + nb);
        bis.close();
      }
      catch (IOException e) {
      }
      finally {
        return ba;
      }
    }
  }

  public void acceptConnections() {

    try {
      serverSocket = new ServerSocket(1921);
    }
    catch (IOException e) {
      System.err.println("ServerSocket instantiation failure");
      e.printStackTrace();
      System.exit(0);
    }

    while (true) {
      try {
        Socket newConnection = serverSocket.accept();
        System.out.println("accepted connection");
        ServerThread st = new ServerThread(newConnection);
        new Thread(st).start();
      }
      catch (IOException ioe) {
        System.err.println("server accept failed");
      }
    }
  }
    
  public static void main(String args[]) {

    SignatureServer server = new SignatureServer();

    server.acceptConnections();
  }

}