How to send image over a network

[Garry Kalra]

Hi,
Since the BufferedImage class does not implement the Serializable interface, how can i send an image over a network, say using RMI.
Since i am a bit (or maybe a byte) weak in graphics, the question may be too simple.
I would be grateful if someone could give me the name of a book to make swing, 2d graphics strong.
Garry

[Joe Gilvary]

Garry,
I think you can go from BufferedImage to a Raster
with getData().
From the Raster you can call getDataBuffer(). The
DataBuffer class is abstract, so you have to find
out (or already know) which subclass you really
have. getDataType() on the DataBuffer can tell you
that.
If your DataBuffer is DataBufferByte, for instance,
then you could get an array byte[][] by calling
getBankData() on the DataBufferByte. Then you have
the data as primitives.
There is an online Programmer's Guide to Java 2D at:
http://java.sun.com/products/jdk/1.2/docs/guide/2d/spec/j2d-title.fm.html
Before the 2D API, the David Geary book "Graphic
Java" was very good. I have not read the later
editions. Look for user reviews at online book sellers.
HTH,
Joe

[Dale Mitchell]

Depending on what you want to do with the image you could convert the BufferedImage into some other format. In jdk1.2 and 1.3 there is a package called com.sun.image.codec.jpeg that can encode your BufferedImage into a JPEG. This image can be sent via RMI. On the other end, you can use this image as is or use the JPEGImageDecoder class to create a BufferedImage from the transported byte[].

  
import java.io.*;
import java.awt.image.*;
import com.sun.image.codec.jpeg.*;
public class TransportableImage implements Serializable{
private byte[] imageBytes;
private transient BufferedImage bufferedImage;

//Constructor converts BufferedImage into a JPEG
//Storing the data in imageBytes[]
public TransportableImage(BufferedImage bufferedImage) throws IOException{
this.bufferedImage = bufferedImage;
ByteArrayOutputStream bos = new ByteArrayOutputStream();
JPEGImageEncoder jpg = JPEGCodec.createJPEGEncoder(bos);
jpg.encode(bufferedImage);
bos.flush();
imageBytes = bos.toByteArray();
bos.close();
}
//Reconstruct the BufferedImage
public BufferedImage createBufferedImage() throws IOException{
InputStream is = new ByteArrayInputStream(imageBytes);
JPEGImageDecoder decoder = JPEGCodec.createJPEGDecoder(is);
BufferedImage image = decoder.decodeAsBufferedImage();
is.close();
return image;
}
//Save a JPEG image
public void toFile(String name) throws IOException{
FileOutputStream os = new FileOutputStream(name);
os.write(imageBytes, 0, imageBytes.length);
os.flush();
os.close();
}
}

Dale

[Gregg Bolinger]

This is a client and server I made to transfer any kind of file to anothe computer over a network. It is really rough and REALLY limited and all command line based. But it might give you an idea.
Client.java

//=====================================================
//Client.java
//Usage: java Client ipaddress port file
//=====================================================
//Imports
import java.net.*;
import java.io.*;
public class Client {


//Main Method
public static void main(String[] args) {


//Get IP from command line
String host = args[0];

//Get port from command line and parse from string to int
int port = Integer.parseInt(args[1]);

//Creating Streams
BufferedInputStream fileIn = null;
BufferedOutputStream out = null;

//Create file based on file from command line
File file = new File(args[2]);

//Check that file exists
if (!file.exists()) {
System.out.println("No such file");
System.exit(0);
}



try{

//create new Input Stream
fileIn = new BufferedInputStream(new FileInputStream(file));

}catch(IOException eee) {System.out.println("Problem creating File"); }

try{
//Create InetAddress
InetAddress theAddress = InetAddress.getByName(host);

try{

System.out.println("Creating Socket");
//Open the Socket
Socket s = new Socket(theAddress, port);
System.out.println("Created Socket");

//Create the output stream to the socket
out = new BufferedOutputStream(s.getOutputStream());

//creates a new buffer byte array
byte[] buffer = new byte[1024];
int numRead;

/////////////////////////////////////////////////////////
//numRead will equal bytes read by fileIn.  When there 
//are no more bytes to be read, numRead will equal 0
//and the while loop will end
/////////////////////////////////////////////////////////
while( (numRead = fileIn.read(buffer)) >= 0) {

System.out.println(numRead);

//write the bytes to the output stream from 0 to total bytes
System.out.println("Writing the File to the out stream");
out.write(buffer, 0, numRead);

}


//flush the output stream
out.flush();
//close the output stream
out.close();
//close the input stream
fileIn.close();
//close the socket
s.close();
System.out.println("everything closed");

System.out.println("File Copy Completed");
}
catch (IOException e) {
}

}catch(UnknownHostException e) {
System.err.println(e);
}



}


}

Server.java

///////////////////////////////////////////////////////////
//Server.java
//Usage:  java Server port
///////////////////////////////////////////////////////////
//imports
import java.net.*;
import java.io.*;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.SimpleTimeZone;
import java.util.Calendar;
public class Server {

//Main method
public static void main(String[] args) {

//get port from command line and parse from String to int
int port = Integer.parseInt(args[0]);
File file = new File("temp.tmp");

try{

//Create a Server Socket
ServerSocket server = new ServerSocket(port);

//Create a Socket
Socket connection = null;
Socket connection1 = null;

while (true) {

try{

//Set connection Socket = to incomming socket from client
connection = server.accept();
System.out.println("Server accept");


//Create the streams
BufferedInputStream in = new BufferedInputStream(connection.getInputStream());
BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(file));


//Create a buffer byte array
byte[] buff = new byte[1024];
int readMe;

//set Begin transfer date
Date begin = new Date();
System.out.println("Started Transfer at: " + begin.toString());
/////////////////////////////////////////////////////////
//readMe will equal bytes read by in.  When there 
//are no more bytes to be read, readMe will equal 0
//and the while loop will end
/////////////////////////////////////////////////////////
while( (readMe = in.read(buff)) >= 0) {

//write the file out to disk from the input stream
out.write(buff, 0, readMe);


}





//Create End transfer date
Date end = new Date();
System.out.println("Ended Transfer at " + end.toString());
long msecs = begin.getTime() - end.getTime();
// Create a GregorianCalendar and set its time zone to GMT
GregorianCalendar delta = new GregorianCalendar(
new SimpleTimeZone(0, ""));
// Set the calendar's time to the difference between the two
delta.setTime(new Date(Math.abs(msecs)));
// The "base" year is 1970, so subtract that number
System.out.println("Years: " +(delta.get(Calendar.YEAR) - 1970));
System.out.println("Months: " + delta.get(Calendar.MONTH));
// The "base" date is 1, so subtract that number
System.out.println("Days: " + (delta.get(Calendar.DATE) - 1));
System.out.println("Hours: " + delta.get(Calendar.HOUR));
System.out.println("Minutes: " + delta.get(Calendar.MINUTE));
System.out.println("Seconds: " + delta.get(Calendar.SECOND));
System.out.println("Milliseconds: " + delta.get(Calendar.MILLISECOND));

//Close the connection socket
connection.close();
//close the input stream
in.close();
//flush the output stream
out.flush();
//close the outpust stream
out.close();

System.out.println("I have recieved the File");
}catch(IOException e) {System.out.println("Exception " + e.getMessage());}
finally {
try {
if (connection != null) connection.close();
}catch(IOException e) {}
}
}
}catch(IOException e) {
System.err.println(e);
}


}
}

Good luck!