// a Java socket client// Keith Vertanen 11/98import java.io.*;import java.net.*;import java.awt.*;public class Client {   boolean VERBOSE = true;		 // turn on/off debugging output   static int BUFFSIZE = 128000;         // how many bytes our incoming buffer can hold   byte data[];   byte buff[];   int port;   int dataport;   String host;   Socket sock;   DatagramSocket recv_sock, send_sock;   BufferedInputStream input;   BufferedOutputStream output;      // constructor, takes a port number, a machine name host, and a bit   // that indicates whether to reverse the byte order or not   public Client(int p, int datap, String address, int rev) throws IOException   {	port = p;	dataport = datap;	host = address;          try {	      	sock = new Socket( InetAddress.getByName(address),                               port );	    	input = new BufferedInputStream(sock.getInputStream(), BUFFSIZE);	  	output = new BufferedOutputStream(sock.getOutputStream(),BUFFSIZE);	}      	catch ( IOException e ) {         	e.printStackTrace();      	}	// allocate the datagram socket	try {		recv_sock = new DatagramSocket(dataport);		send_sock = new DatagramSocket();	} 	catch (SocketException se) {		se.printStackTrace();	}	// amortize the buffer allocation by just doing it once	buff = new byte[BUFFSIZE];	data = new byte[BUFFSIZE];	if (VERBOSE) System.out.println("Client: opening socket to " +			address + " on port " + port + 			", datagrams on port = " +dataport);	// now we want to tell the server if we want reversed bytes or not	output.write(rev);	output.flush();		if (VERBOSE) 		if (rev==1) 			System.out.println("Client:  requested reversed bytes");		else			System.out.println("Client:  requested normal byte order");   }   // send a string down the socket   public void send_string(String str) throws IOException   {	/* convert our string into an array of bytes */	ByteArrayOutputStream bytestream;	bytestream = new ByteArrayOutputStream(str.length());	DataOutputStream out;	out = new DataOutputStream(bytestream);	for (int i=0; i<str.length(); i++)		out.write((byte) str.charAt(i));	output.write(bytestream.toByteArray(), 0, bytestream.size());	output.flush(); 	if (VERBOSE) System.out.println("Client: sending '" + str +"'");	recv_ack();	send_ack();   }   public void send_bytes(byte vals[], int len) throws IOException   {	if (VERBOSE) 	{		System.out.print("Client: sending " + len +" bytes: ");		for (int i=0; i<len; i++)			System.out.print(vals[i] + " ");	}	output.write(vals, 0, len);	output.flush(); 	if (VERBOSE) System.out.println("");	recv_ack();	send_ack();   }   public void send_ints(int vals[], int len) throws IOException   {	if (VERBOSE) System.out.print("Client: sending " + len +" ints: ");	/* convert our array of ints into an array of bytes */	ByteArrayOutputStream bytestream;	bytestream = new ByteArrayOutputStream(len*4);	DataOutputStream out;	out = new DataOutputStream(bytestream);	for (int i=0; i<len; i++)	{		out.writeInt(vals[i]);	 	if (VERBOSE) System.out.print(vals[i]+" ");	}		output.write(bytestream.toByteArray(), 0, bytestream.size());	output.flush(); 	if (VERBOSE) System.out.println("");	recv_ack();	send_ack();   }   public void send_floats(float vals[], int len) throws IOException   {	if (VERBOSE) System.out.print("Client: sending " + len +" floats: ");	/* convert our array of floats into an array of bytes */	ByteArrayOutputStream bytestream;	bytestream = new ByteArrayOutputStream(len*4);	DataOutputStream out;	out = new DataOutputStream(bytestream);	for (int i=0; i<len; i++)	{		out.writeFloat(vals[i]);	 	if (VERBOSE) System.out.print(vals[i]+" ");	}		output.write(bytestream.toByteArray(), 0, bytestream.size());	output.flush(); 	if (VERBOSE) System.out.println("");	recv_ack();	send_ack();   }   public void send_doubles(double vals[], int len) throws IOException   {	if (VERBOSE) System.out.print("Client: sending " + len +" doubles: ");	/* convert our array of floats into an array of bytes */	ByteArrayOutputStream bytestream;	bytestream = new ByteArrayOutputStream(len*8);	DataOutputStream out;	out = new DataOutputStream(bytestream);	for (int i=0; i<len; i++)	{		out.writeDouble(vals[i]);	 	if (VERBOSE) System.out.print(vals[i]+" ");	}		output.write(bytestream.toByteArray(), 0, bytestream.size());	output.flush();	if (VERBOSE) System.out.println("");		recv_ack();	send_ack();   }   public void send_datagram(byte vals[], int len) throws IOException   {	DatagramPacket sendPacket;	if (VERBOSE) 	{		System.out.print("Client: sending datagram of " + len +" bytes: ");		for (int i=0; i<len; i++)			System.out.print(vals[i] + " ");	}	sendPacket = new DatagramPacket(vals, len,					InetAddress.getByName(host), dataport);	send_sock.send(sendPacket); 	if (VERBOSE) System.out.println("");   }   // recv a string from the socket (terminates on terminal char)   public String recv_string(char terminal) throws IOException   {	char c;	String out;	// would have liked to use readUTF, but it didn't seem to work	// when talking to the c++ server	out = new String("");	while ((c=(char) input.read())!=terminal)		out = out + String.valueOf(c); 	if (VERBOSE) System.out.println("Client: recv'd '" + out +"'");	send_ack();	recv_ack();	return out;   }  public int recv_bytes(byte val[], int maxlen) throws IOException  {       int i;       int totalbytes = 0;       int numbytes;	if (maxlen>BUFFSIZE)		System.out.println("Sending more bytes then will fit in buffer!");	while (totalbytes < maxlen)	{		numbytes = input.read(data);		// copy the bytes into the result buffer		for (i=totalbytes; i<totalbytes+numbytes; i++)			val[i] = data[i-totalbytes];		totalbytes += numbytes;	}	if (VERBOSE) 	{		System.out.print("Client: received " + maxlen + " bytes - ");		for (i=0; i<maxlen; i++)			System.out.print(val[i]+" ");		System.out.println("");	}	// we now send an acknowledgement to the server to let them	// know we've got it	send_ack();	recv_ack();	return maxlen;  }  public int recv_ints(int val[], int maxlen) throws IOException  {       int i;       int totalbytes = 0;       int numbytes;	/* for performance, we need to receive data as an array of bytes		and then convert to an array of ints, more fun than		you can shake a stick at! */	if (maxlen*4>BUFFSIZE)		System.out.println("Sending more ints then will fit in buffer!");	while (totalbytes < maxlen*4)	{		numbytes = input.read(data);		// copy the bytes into the result buffer		for (i=totalbytes; i<totalbytes+numbytes; i++)			buff[i] = data[i-totalbytes];		totalbytes += numbytes;	}	// now we must convert the array of bytes to an array of ints        ByteArrayInputStream bytestream;	DataInputStream instream;	bytestream = new ByteArrayInputStream(buff);	instream = new DataInputStream(bytestream);	for (i=0; i<maxlen; i++)		val[i] = instream.readInt();	if (VERBOSE) 	{		System.out.print("Client: received " + maxlen + " ints - ");		for (i=0; i<maxlen; i++)			System.out.print(val[i]+" ");		System.out.println("");	}	// we now send an acknowledgement to the server to let them	// know we've got it	send_ack();	recv_ack();	return maxlen;  }  public int recv_doubles(double val[], int maxlen) throws IOException  {       int i;       int numbytes;       int totalbytes = 0;	/* for performance, we need to receive data as an array of bytes		and then convert to an array of ints, more fun than		you can shake a stick at! */	if (maxlen*8>BUFFSIZE)		System.out.println("Sending more doubles then will fit in buffer!");	while (totalbytes < maxlen*8)	{		numbytes = input.read(data);		// copy the bytes into the result buffer		for (i=totalbytes; i<totalbytes+numbytes; i++)			buff[i] = data[i-totalbytes];		totalbytes += numbytes;		}	// now we must convert the array of bytes to an array of ints        ByteArrayInputStream bytestream;	DataInputStream instream;	bytestream = new ByteArrayInputStream(buff);	instream = new DataInputStream(bytestream);	for (i=0; i<maxlen; i++)		val[i] = instream.readDouble();	if (VERBOSE) 	{		System.out.print("Client: received " + maxlen + " doubles - ");		for (i=0; i<maxlen; i++)			System.out.print(val[i]+" ");		System.out.println("");	}	send_ack();	recv_ack();	return maxlen;  }  public int recv_floats(float val[], int maxlen) throws IOException  {       int i;       int numbytes;       int totalbytes = 0;	/* for performance, we need to receive data as an array of bytes		and then convert to an array of ints, more fun than		you can shake a stick at! */	if (maxlen*4>BUFFSIZE)		System.out.println("Sending more doubles then will fit in buffer!");	while (totalbytes < maxlen*4)	{		numbytes = input.read(data);		// copy the bytes into the result buffer		for (i=totalbytes; i<totalbytes+numbytes; i++)			buff[i] = data[i-totalbytes];		totalbytes += numbytes;	}	// now we must convert the array of bytes to an array of ints        ByteArrayInputStream bytestream;	DataInputStream instream;	bytestream = new ByteArrayInputStream(buff);	instream = new DataInputStream(bytestream);	for (i=0; i<maxlen; i++)		val[i] = instream.readFloat();	if (VERBOSE) 	{		System.out.print("Client: received " + maxlen + " floats - ");		for (i=0; i<maxlen; i++)			System.out.print(val[i]+" ");		System.out.println("");	}	send_ack();	recv_ack();	return maxlen;  }  public int recv_datagram(byte val[], int maxlen) throws IOException  {        int i;        int numbytes;	DatagramPacket receivePacket;	if (maxlen>BUFFSIZE)		System.out.println("Sending more bytes then will fit in buffer!");	receivePacket = new DatagramPacket(val, maxlen);	recv_sock.receive(receivePacket);	numbytes = receivePacket.getLength();	if (VERBOSE) 	{		System.out.print("Client: received " + numbytes + " bytes - ");		for (i=0; i<numbytes; i++)			System.out.print(val[i]+" ");		System.out.println("");	}	return numbytes;  }   // shutdown the socket   public void closesocket() throws IOException   {	sock.close(); 	if (VERBOSE) System.out.println("Client: closing socket");   }   // send a short ack to the server so they know we are ready for more   private void send_ack() throws IOException   {	int ack;	ack = 0;	if (VERBOSE)		System.out.println("Sending ack...");	output.write(ack);	output.flush();   }   // recv a short ack from the server so we know they are ready for more   private void recv_ack() throws IOException   {	int ack;	if (VERBOSE)		System.out.println("Waiting for ack...");	ack = (int) input.read();	if (VERBOSE)		System.out.println("Ack recieved.");   }}