/* -*- mode: java; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
Client - basic network client implementation
Part of the Processing project - http://processing.org
Copyright (c) 2004-2007 Ben Fry and Casey Reas
The previous version of this code was developed by Hernando Barragan
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General
Public License along with this library; if not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330,
Boston, MA 02111-1307 USA
*/
package processing.net;
import processing.core.*;
import java.io.*;
import java.lang.reflect.*;
import java.net.*;
/**
* A client connects to a server and sends data back and forth.
* If anything goes wrong with the connection,
* for example the host is not there or is listening on a different port,
* an exception is thrown.
*
* @webref
* @brief The client class is used to create client Objects which connect to a server to exchange data.
* @instanceName client any variable of type Client
* @usage Application
*/
public class Client implements Runnable {
PApplet parent;
Method clientEventMethod;
Method disconnectEventMethod;
Thread thread;
Socket socket;
String ip;
int port;
String host;
public InputStream input;
public OutputStream output;
byte buffer[] = new byte[32768];
int bufferIndex;
int bufferLast;
/**
*
* @param parent typically use "this"
* @param host address of the server
* @param port port to read/write from on the server
*/
public Client(PApplet parent, String host, int port) {
this.parent = parent;
this.host = host;
this.port = port;
try {
socket = new Socket(this.host, this.port);
input = socket.getInputStream();
output = socket.getOutputStream();
thread = new Thread(this);
thread.start();
parent.registerDispose(this);
// reflection to check whether host applet has a call for
// public void clientEvent(processing.net.Client)
// which would be called each time an event comes in
try {
clientEventMethod =
parent.getClass().getMethod("clientEvent",
new Class[] { Client.class });
} catch (Exception e) {
// no such method, or an error.. which is fine, just ignore
}
// do the same for disconnectEvent(Client c);
try {
disconnectEventMethod =
parent.getClass().getMethod("disconnectEvent",
new Class[] { Client.class });
} catch (Exception e) {
// no such method, or an error.. which is fine, just ignore
}
} catch (ConnectException ce) {
ce.printStackTrace();
dispose();
} catch (IOException e) {
e.printStackTrace();
dispose();
}
}
/**
* @param socket any object of type Socket
* @throws IOException
*/
public Client(PApplet parent, Socket socket) throws IOException {
this.socket = socket;
input = socket.getInputStream();
output = socket.getOutputStream();
thread = new Thread(this);
thread.start();
}
/**
* Disconnects from the server. Use to shut the connection when you're finished with the Client.
* =advanced
* Disconnect from the server and calls disconnectEvent(Client c)
* in the host PApplet.
* <P/>
* Use this to shut the connection if you're finished with it
* while your applet is still running. Otherwise, it will be
* automatically be shut down by the host PApplet
* (using dispose, which is identical)
* @webref
* @brief Disconnects from the server
*/
public void stop() {
dispose();
if (disconnectEventMethod != null) {
try {
disconnectEventMethod.invoke(parent, new Object[] { this });
} catch (Exception e) {
e.printStackTrace();
disconnectEventMethod = null;
}
}
}
/**
* Disconnect from the server: internal use only.
* <P>
* This should only be called by the internal functions in PApplet,
* use stop() instead from within your own applets.
*/
public void dispose() {
thread = null;
try {
// do io streams need to be closed first?
if (input != null) input.close();
if (output != null) output.close();
} catch (Exception e) {
e.printStackTrace();
}
input = null;
output = null;
try {
if (socket != null) socket.close();
} catch (Exception e) {
e.printStackTrace();
}
socket = null;
}
public void run() {
while (Thread.currentThread() == thread) {
try {
while ((input != null) &&
(input.available() > 0)) { // this will block
synchronized (buffer) {
if (bufferLast == buffer.length) {
byte temp[] = new byte[bufferLast << 1];
System.arraycopy(buffer, 0, temp, 0, bufferLast);
buffer = temp;
}
buffer[bufferLast++] = (byte) input.read();
}
}
// now post an event
if (clientEventMethod != null) {
try {
clientEventMethod.invoke(parent, new Object[] { this });
} catch (Exception e) {
System.err.println("error, disabling clientEvent() for " + host);
e.printStackTrace();
clientEventMethod = null;
}
}
try {
// uhh.. not sure what's best here.. since blocking,
// do we need to worry about sleeping much? or is this
// gonna try to slurp cpu away from the main applet?
Thread.sleep(10);
} catch (InterruptedException ex) { }
} catch (IOException e) {
//errorMessage("run", e);
e.printStackTrace();
}
}
}
/**
* Return true if this client is still active and hasn't run
* into any trouble.
*/
public boolean active() {
return (thread != null);
}
/**
* Returns the IP address of the computer to which the Client is attached.
* @brief Returns the IP address of the machine as a String
* @webref
*/
public String ip() {
return socket.getInetAddress().getHostAddress();
}
/**
* Returns the number of bytes available. When any client has bytes available from the server, it returns the number of bytes.
* @webref
* @brief Returns the number of bytes in the buffer waiting to be read
*/
public int available() {
return (bufferLast - bufferIndex);
}
/**
* Empty the buffer, removes all the data stored there.
*
* @webref
* @brief Clears the buffer
*/
public void clear() {
bufferLast = 0;
bufferIndex = 0;
}
/**
* Returns a number between 0 and 255 for the next byte that's waiting in the buffer.
* Returns -1 if there is no byte, although this should be avoided by first cheacking <b>available()</b> to see if any data is available.
*
* @webref
* @brief Returns a value from the buffer
*/
public int read() {
if (bufferIndex == bufferLast) return -1;
synchronized (buffer) {
int outgoing = buffer[bufferIndex++] & 0xff;
if (bufferIndex == bufferLast) { // rewind
bufferIndex = 0;
bufferLast = 0;
}
return outgoing;
}
}
/**
* Returns the next byte in the buffer as a char.
* Returns -1, or 0xffff, if nothing is there.
*
* @webref
* @brief Returns the next byte in the buffer as a char
*/
public char readChar() {
if (bufferIndex == bufferLast) return (char)(-1);
return (char) read();
}
/**
* Reads a group of bytes from the buffer.
* The version with no parameters returns a byte array of all data in the buffer.
* This is not efficient, but is easy to use.
* The version with the <b>byteBuffer</b> parameter is more memory and time efficient.
* It grabs the data in the buffer and puts it into the byte array passed in and returns an int value for the number of bytes read.
* If more bytes are available than can fit into the <b>byteBuffer</b>, only those that fit are read.
* =advanced
* Return a byte array of anything that's in the serial buffer.
* Not particularly memory/speed efficient, because it creates
* a byte array on each read, but it's easier to use than
* readBytes(byte b[]) (see below).
*
* @webref
* @brief Reads everything in the buffer
*/
public byte[] readBytes() {
if (bufferIndex == bufferLast) return null;
synchronized (buffer) {
int length = bufferLast - bufferIndex;
byte outgoing[] = new byte[length];
System.arraycopy(buffer, bufferIndex, outgoing, 0, length);
bufferIndex = 0; // rewind
bufferLast = 0;
return outgoing;
}
}
/**
* Grab whatever is in the serial buffer, and stuff it into a
* byte buffer passed in by the user. This is more memory/time
* efficient than readBytes() returning a byte[] array.
*
* Returns an int for how many bytes were read. If more bytes
* are available than can fit into the byte array, only those
* that will fit are read.
*
* @param bytebuffer passed in byte array to be altered
*/
public int readBytes(byte bytebuffer[]) {
if (bufferIndex == bufferLast) return 0;
synchronized (buffer) {
int length = bufferLast - bufferIndex;
if (length > bytebuffer.length) length = bytebuffer.length;
System.arraycopy(buffer, bufferIndex, bytebuffer, 0, length);
bufferIndex += length;
if (bufferIndex == bufferLast) {
bufferIndex = 0; // rewind
bufferLast = 0;
}
return length;
}
}
/**
* Reads from the port into a buffer of bytes up to and including a particular character.
* If the character isn't in the buffer, 'null' is returned.
* The version with no <b>byteBuffer</b> parameter returns a byte array of all data up to and including the <b>interesting</b> byte.
* This is not efficient, but is easy to use. The version with the <b>byteBuffer</b> parameter is more memory and time efficient.
* It grabs the data in the buffer and puts it into the byte array passed in and returns an int value for the number of bytes read.
* If the byte buffer is not large enough, -1 is returned and an error is printed to the message area. If nothing is in the buffer, 0 is returned.
*
* @webref
* @brief Reads from the buffer of bytes up to and including a particular character
* @param interesting character designated to mark the end of the data
*/
public byte[] readBytesUntil(int interesting) {
if (bufferIndex == bufferLast) return null;
byte what = (byte)interesting;
synchronized (buffer) {
int found = -1;
for (int k = bufferIndex; k < bufferLast; k++) {
if (buffer[k] == what) {
found = k;
break;
}
}
if (found == -1) return null;
int length = found - bufferIndex + 1;
byte outgoing[] = new byte[length];
System.arraycopy(buffer, bufferIndex, outgoing, 0, length);
bufferIndex += length;
if (bufferIndex == bufferLast) {
bufferIndex = 0; // rewind
bufferLast = 0;
}
return outgoing;
}
}
/**
* Reads from the serial port into a buffer of bytes until a
* particular character. If the character isn't in the serial
* buffer, then 'null' is returned.
*
* If outgoing[] is not big enough, then -1 is returned,
* and an error message is printed on the console.
* If nothing is in the buffer, zero is returned.
* If 'interesting' byte is not in the buffer, then 0 is returned.
*
* @param byteBuffer passed in byte array to be altered
*/
public int readBytesUntil(int interesting, byte byteBuffer[]) {
if (bufferIndex == bufferLast) return 0;
byte what = (byte)interesting;
synchronized (buffer) {
int found = -1;
for (int k = bufferIndex; k < bufferLast; k++) {
if (buffer[k] == what) {
found = k;
break;
}
}
if (found == -1) return 0;
int length = found - bufferIndex + 1;
if (length > byteBuffer.length) {
System.err.println("readBytesUntil() byte buffer is" +
" too small for the " + length +
" bytes up to and including char " + interesting);
return -1;
}
//byte outgoing[] = new byte[length];
System.arraycopy(buffer, bufferIndex, byteBuffer, 0, length);
bufferIndex += length;
if (bufferIndex == bufferLast) {
bufferIndex = 0; // rewind
bufferLast = 0;
}
return length;
}
}
/**
* Returns the all the data from the buffer as a String.
* This method assumes the incoming characters are ASCII.
* If you want to transfer Unicode data,
* first convert the String to a byte stream in the representation of your choice
* (i.e. UTF8 or two-byte Unicode data), and send it as a byte array.
*
* @webref
* @brief Returns the buffer as a String
*/
public String readString() {
if (bufferIndex == bufferLast) return null;
return new String(readBytes());
}
/**
* Combination of <b>readBytesUntil()</b> and <b>readString()</b>. Returns <b>null</b> if it doesn't find what you're looking for.
* =advanced
* <p/>
* If you want to move Unicode data, you can first convert the
* String to a byte stream in the representation of your choice
* (i.e. UTF8 or two-byte Unicode data), and send it as a byte array.
*
* @webref
* @brief Returns the buffer as a String up to and including a particular character
* @param interesting character designated to mark the end of the data
*/
public String readStringUntil(int interesting) {
byte b[] = readBytesUntil(interesting);
if (b == null) return null;
return new String(b);
}
/**
* Writes data to a server specified when constructing the client.
*
* @webref
* @brief Writes bytes, chars, ints, bytes[], Strings
* @param data data to write
*/
public void write(int data) { // will also cover char
try {
output.write(data & 0xff); // for good measure do the &
output.flush(); // hmm, not sure if a good idea
} catch (Exception e) { // null pointer or serial port dead
//errorMessage("write", e);
//e.printStackTrace();
//dispose();
//disconnect(e);
e.printStackTrace();
stop();
}
}
public void write(byte data[]) {
try {
output.write(data);
output.flush(); // hmm, not sure if a good idea
} catch (Exception e) { // null pointer or serial port dead
//errorMessage("write", e);
//e.printStackTrace();
//disconnect(e);
e.printStackTrace();
stop();
}
}
/**
* Write a String to the output. Note that this doesn't account
* for Unicode (two bytes per char), nor will it send UTF8
* characters.. It assumes that you mean to send a byte buffer
* (most often the case for networking and serial i/o) and
* will only use the bottom 8 bits of each char in the string.
* (Meaning that internally it uses String.getBytes)
*
* If you want to move Unicode data, you can first convert the
* String to a byte stream in the representation of your choice
* (i.e. UTF8 or two-byte Unicode data), and send it as a byte array.
*/
public void write(String data) {
write(data.getBytes());
}
/**
* Handle disconnect due to an Exception being thrown.
*/
/*
protected void disconnect(Exception e) {
dispose();
if (e != null) {
e.printStackTrace();
}
}
*/
/**
* General error reporting, all corraled here just in case
* I think of something slightly more intelligent to do.
*/
//public void errorMessage(String where, Exception e) {
//parent.die("Error inside Client." + where + "()", e);
//e.printStackTrace(System.err);
//}
}