I am creating a server that stores application updates. When the client connects the server send the update. The server is sending the file but the file is not complete, i.e, if the file is 317kb,its send 117kb. Below is the code I am using :
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
public class TestFileServer {
I have two programs that I'll post below, one is a Server and the other is a Client. The ChatServer runs once and many clients can run ChatClient from separate computers and talk together in their GUI's. The the client program comes with two buttons, one that's simulates the sending of a message to a single user ; "Send Message To User", and one that just generally sends a message ; "Send Message To All". Although now the Clients on the server seem to be able to selectively send messages to an individual by giving the recipient name, all the clients can see that message, which is not exact what I am aiming for. What I am going for is having the "Send Message To User" button click to send a message to the named user without all other users seeing the message.
Now I have tried thing like having various input output streams and trying to connect those, but no luck. Tried fiddling with having the names arraylist directing the messages to one client versus all but that did not work out either. How I what I would need to do to go about doing this?
I've just recently started playing around with network programming in Java, and I've come up with a simplistic server than can handle multiple clients and return the IP and port each one is connected to (or I'm under the impression that is so). What I've been requested to do as an exercise by one of the programming teachers at my high school (I'm not in a class, this is my own time) is send a message from one client to the other through the ServerSocket so that it may "watch" everything going on. I'm not sure how to go about this at all.
EDIT : now it never seems to go the the else or else if statements...
That is now the main problem. It never, ever, goes past the first if statement, no matter what it is.
EDIT : Okay, I haven't changed a line of code but suddenly not a single if statement is working. They just stopped. The client simply hangs and I can't type anything.
Server
public class Server implements Runnable { Socket clientSocket; Server(Socket clientSocket) { this.clientSocket = clientSocket; } public static void main(String args[]) throws Exception { ServerSocket ssock = new ServerSocket(3480); System.out.println("Listening on port 3480");
I am trying to check the integrity in a Bank Transaction that the message sent to the server has not been modified by any malware in the client system. For this I am trying to read the message sent to the server at the client boundary so as that it enters the network as customer with customer intended values. So, firstly I need to check where to I need intercept the message within client boundary. Secondly, Can I intercept the message and read its contents using Java?
I want to check what my Online Banking Server( Leta Say Bank of America) receives if I ask to transfer amount $100 to Account A . I assume that there is a malware in client system that changes recipient to B,$10000. My aplicaion which I intend to design, shoudl inform the user that the integrity of the message is compromised and should give the option to the user to abort it. plan to track what message is being sent from client to server. This I want to achieve by reading the message from client at the last point before it leaves the client and enter the network.
I have to write a client and server class for a UDP protocol sending integer numbers by UDP packets. So far i have this;
Client Code:
import java.io.*; import java.net.*; class UDPClient { public static void main(String args[]) throws Exception { BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));
[Code] ....
But i now need to change this so that:
The client;
1. Reads an integer from keyboard input and stores its value in a UDP packet. // byte[] send = ByteBuffer.allocate(4).putInt(num).array(); ???
2. Sends the UDP packet to the server, on port number 1999;
3. Listens for UDP packets from the server (until it receives a packet with a non-positive number; see step (b) below). While listening:
(a) Once it receives a UDP packet from the server, it subtracts 2 from the integer value num contained in it. // int num = ByteBuffer.wrap(receive).getInt(); ??? (b) Checks the integer value num: if the value is greater than 0 (num>0) then the client stores it in a new UDP packet and sends the packet to the server; otherwise (num<=0) the client terminates.
The Server;
1. Listens on port 1999;
2. For each UDP packet it receives from a client: (a) extracts the integer value n contained in it; (b) decreases the value of n by 2; (c) sends back to the client a UDP packet containing the new value of n.
I'm trying to do a program that send a single file from a client to a default directory of a Server. The program use the datagramSocket and datagramPacket for the transfer via UDP. The client sent the packet of the file correctly and the server start the receiving but every time the Server class crashes after it's receiving 4/5 packet (exactly 8192 byte)
Then i put the code of the 2 class and the 2 output.
OUTPUT CLIENT:
PROGRAM TRANSFER PACKAGES name of file is : Doc1.pdf his dimension: 11408 byte
PROGRAM TRANSFER PACKAGES START NEW CONNECTION Directory: C:prova Server waiting in port: 9876 Waiting Client... Name of file is : Doc1.pdf Dimension : 11408
[Code] ....
In this point the program go in loop and didn't anything. I don't understand how can i resolve it...
I'm making a class in Android that takes a photo, list a photos in Listview, and then sends them all to server. I'm stuck on listing them. How to send them all to server.
I am attempting to test a TCP Client and Server for an assignment I am doing in class. The goal here is to "test your client and Server applications by transferring (i) a file having 10,000+ lines (see supplied big-file1.txt having 12000+ lines), (ii) a file having 20,000+ lines (you may create one of your own from big-file1.txt, or obtain a large size file from the Google website at [URL] ...). Then, compute and display the total transfer time of the files at both of the sides separately (your choice in millisecond/second)."
I have created the TCPClient and TCPServer java classes, ran the server first and then the client, and using mathematical formulas to calculate the transfer time. Trouble is, I'm having trouble testing the client and server in the file area and not the area where I had to input a line, let the server print it, and then have the client eliminate the articles from the line. I need testing the file. Here is my code so far:
TCPClient:
package tcpclient; import java.io.*; import java.net.*; public class TCPClient { public static void main(String[] args) throws IOException{ // TODO Auto-generated method stub String sentence;
[code] ....
How to fix the code so that the time in seconds does not output as 60 for both files and that the files go through the exchange?
I have a program using Pipe line to exchange the infomation in the Client-Server model. Can I separate out main function and then put into Server main and Client main?
//PipeEchoServer public class PipedEchoServer extends Thread { PipedInputStream readPipe; PipedOutputStream writePipe; PipedEchoServer(PipedInputStream readPipe, PipedOutputStream writePipe){ this.readPipe = readPipe;
I have to develop a code in parallel which is implemented in sequential yet. How to add the server client relation in the program so that work can be divided into multiple clients.
I have a problem on how to make my client to send the object to a server.
So I have one interface called "RMIInterface" and client "RMIClient" and server "RMIServer":
RMIInterface interface RMIInterface { public String getMessage(String text) throws RemoteException; } RMIClient public class RMIClient {
[code]....
With this program I can connect to a Server with a Client, and print in Client console a message.But, how can I send message from a client to a server, and print that message in server console output?
make the simpliest example with sending a message to a server, edit inteface header code to public interface RMIInterface extends Remote, I forgot to add.
I want to ask that, when a server listen to A port and it accepts a request from a client then the server accepts the request using accept method,but how does the server get the info about the client like wat is the port no and ip address of the client,I read a answer regarding this that Server never gets the port no of client only the ip address and it connects to client using a connection stream but as far I know from networking, a device must have the ip address and port no of the device it wants to connect to.
So we have a Client and Server. Client opens a socket to Server, server initiates new Thread to handle the communication with client. Is there a way to be singnalled when there is input on socket, so I don't have to use infinite while loop solution?
I have gf 4.0.1 and swing client. I want to get EJB over SSL. I've set all certificates. However, I can get it work only when client and server are at the same host. What I see in tcpdump when they are at the same host:
I've been trying to create a server/client chat program, but I keep running into areas where I'm not really sure how to work it. I've run into a wall where my client just sits and spins instead of working. URL.... I can work out the dynamic parts later, I just want to understand the meat and potatoes of reading from sockets and writing to sockets (and how to do both at the same time).
I'm trying to build a SSL mutual authenticating private server. I'm not sure what keystores, truststores, or certificates I need to accomplish this. I made keystores for both programs using:
It's an RMI program that has to be able to return the mean, mode and median of a set of numbers.It's composed of 4 classes; a client, an implementation class (with the math), an Interface, and a server class.
So i wrote this text to try and create a simple chat program that does the following: Prepend names to messages, announce entrance and exit of chat, display user list, and share a whiteboard.So far the Server seems to be working but the Chat Client is throwing errors at me left and right..
CURRENT ERROR: Microsoft Windows [Version 6.1.7601] Copyright (c) 2009 Microsoft Corporation. All rights reserved.
C:Windowssystem32>cd.. C:Windows>cd.. C:>Usersjaydesktopchat 'Usersjaydesktopchat' is not recognized as an internal or external command, operable program or batch file.
I'm working on an assignment right now which involves passing a variable series of numbers to the Server to be sorted into the correct order and returned to the client.
So far I have it connecting to the server and asking for my numbers, and I am entering each number and pressing return, and it is accepting each number individually.
One (smaller I think) problem i'm having is with the client code, specifically the while loop.. I've tried to code it so that when I enter a full stop ('.') the program will stop asking me for more numbers and move on to sending them to the server.. but instead it just crashes giving an error.. heres an example
"Enter a number: 1 Enter a number: 3 Enter a number: 2 Enter a number: 1. java.lang.NumberFormatException: For input string: "1." at java.lang.NumberFormatException.forInputString(Num berFormatException.java:65)
[Code] ....
Here's the client code in full
package numberSortprogram; import java.io.*; import java.net.ServerSocket; public class NumSortClient { public static void main(String[] args) { InputStreamReader is = new InputStreamReader(System.in); [Code] ....
The big problem that I have is figuring out how to send the sorted array back to the client..
So, what im trying to get to happen is-
-Client is asked to enter numbers -Client enters series of numbers into an array -Array is converted to a string and sent to the server -String is then split into an array of strings and sorted using compareTo (don't know if this is the best way?) -Sorted array is sent back to client and displayed.
fyi this is making use of streamsockets..
All of the rest of my code is below:
package numberSortprogram; import java.io.IOException; import java.net.*; import java.util.regex.PatternSyntaxException; public class NumSortServer { public static void main(String[] args) { int serverPort = 4444; // default port if (args.length == 1 )
I want to send a message to a specific client in a server. This is my code and what I tried(I have only given you 3 classes in which I believe I have the problem).
TextClient:
import java.io.*; import java.net.*; import java.util.ArrayList; import java.util.Scanner; import java.util.concurrent.TimeUnit; public class TextClient { public TextClient() {
I've been provided a code skeleton for what must be done, but despite my best efforts to make things work, I'm coming up dry (obviously, due to a lack of knowledge.) One thing that might work is if I knew how to debug this type of application, line-by-line, to see exactly what is going on. Obviously, it's easy enough to debug the client part, but moving over to the server part, I haven't been able to figure that out (I'm using Eclipse.)
I have a https connection from Client to Server and a malware in client. The malware modifies the message and compromises its integrity. I am using a proxy to check the Integrity of the message after the malware has changed the message and before sending it over the internet to the server.
Now, How can I check the Integrity of the message (Sure that it has not been modified by any Man in the Middle) for the second half of my communication channel(Which is from Client to the Server over the internet).
I see few conventional approaches of CRC or Checksum will work. But I am looking for some non traditional or upcoming approaches.
Ideally SSL Data shouldn't be able to be decrypted by any MIM. But my assumption is that any Protocol is subjected to attack and compromised in real world and few recent studies are proving that https is breakable. Thus, I am trying to perform a What if analysis? On the client side, lets say malware is not more powerful than just modifies the transaction amount and destination account number in a typical online Baking transaction.
