File Empty When Attempt To Transfer Between Computers Using Sockets
May 26, 2014
I am working on a project with client/server relationship and I want the client to be able to transfer their personal music files over the socket. Every time I attempt to do it the file is created but it is empty.
Server code:
Java Code:
public class Server extends JFrame {
//===============================
// FIELDS
//===============================
// connection essentials
private ServerSocket server;
private Socket connection;
I have written a java code to transfer files from one server to another using the concept of socket programming. I got the codes from another java forum that meet my requirements. The program is said to transfer large sized files (like .mkv , .mprg movies) from one machine to another and can be used to transfer files of all formats. But after running the codes I found that the program is not able to transfer large sized files such as movies and even pdf of sizes 80mb or 111mb. When i transfer small sized files, it gets transferred and the output shows that. You can run the codes and observe it. But when i try to transfer large sized files, the program goes on running for hours. The large sized files are not getting transferred. The program has used bytebuffer but still this error occurs.
**ClientMain.java** import java.io.IOException; import java.net.Socket; public class ClientMain
[code]....
Note that:-
1. ClientMain.java and DirectoryTxr.java are the two classes under client application. 2. ServerMain.java and DirectoryRcr.java are the two classes under Server application. 3. run the ClientMain.java and ServerMain.java simultaneously
Also specify the source directory, destination directory and host address of the machine in which server is running in the ClientMain.java(as per your computer). Here we are not specifying source file ,instead a source directory or folder is specifying.So the entire files of source directory will be transferred.
This question has confused me because "Errors" are capitalized and I'm not sure what they mean.
To me this question is false. Sockets can be used to transfers file over a network.
I can't see why this wouldn't work. The code looks fine to me.
I don't think this is true unless you're using the mouseEntered() or mouseExited() method. But again, I'm not sure.
I think this is true, I don't know what else could have listeners.
They're only worth a few marks each so the answer is only suppose to be a line or two. They are all true or false questions that require an explanation.
Okay I am having a problem I wrote some code to transfer a file from my server when requested by the client. The problem is that when the file which is requested is transferred the file cannot be open in its respected file launcher when clicked. The File launcher throws back this msg "My Issue It request the File but after the File is requested and stored on the Client Machine when I Hit the File to be Launch adobe says the file "Adobe could not open the File for it is not supported file type or because the file as been damage"
So i have two pair sets of code for original coded by me. Original code i had first Server
import java.io.*; import java.net.*; public class SimpleFileServer { public final static String FILE_TO_SEND = "c:/Users/Acer/Downloads/COAFlags.pdf"; // you may change this public static void main(String args[]) {
I have to write a code for File Transfer Protocol! It says that I only need to write code for client, but it also says that I have to run the program and send some files to server. I guess than I also need server side as well. I have to write my own classes, I cannot import some existing classes. I have to connect to the server with password and username and after that send some files to the server. I don't know anything about FTP. Can i maybe do this by Sockets and ports? I worked something with that.
I have written a java code to transfer files from one server to another using the concept of socket programming. I got the codes from another java forum that meet my requirements. The program is said to transfer large sized files (like .mkv , .mprg movies) from one machine to another and can be used to transfer files of all formats. But after running the codes I found that the program is not able to transfer large sized files such as movies and even pdf of sizes 80mb or 111mb. When i transfer small sized files, it gets transferred and the output shows that. You can run the codes and observe it. But when i try to transfer large sized files, the program goes on running for hours. The large sized files are not getting transferred. The program has used bytebuffer but still this error occurs. The codes are as follows (I got them from this site [URL] ....)
**ClientMain.java**
import java.io.IOException; import java.net.Socket; public class ClientMain { private DirectoryTxr transmitter = null; Socket clientSocket = null;
[Code] .....
1. ClientMain.java and DirectoryTxr.java are the two classes under client application. 2. ServerMain.java and DirectoryRcr.java are the two classes under Server application. 3. run the ClientMain.java and ServerMain.java simultaneously
Also specify the source directory, destination directory and host address of the machine in which server is running in the ClientMain.java (as per your computer). Here we are not specifying source file, instead a source directory or folder is specifying. So the entire files of source directory will be transferred.
I have written a java code to transfer files from one server to another using the concept of socket programming. I got the codes from another java forum that meet my requirements. The program is said to transfer large sized files (like .mkv , .mprg movies) from one machine to another and can be used to transfer files of all formats. But after running the codes I found that the program is not able to transfer large sized files such as movies and even pdf of sizes 80mb or 111mb. When i transfer small sized files, it gets transferred and the output shows that. You can run the codes and observe it. But when i try to transfer large sized files, the program goes on running for hours. The large sized files are not getting transferred. The program has used bytebuffer but still this error occurs. The codes are as follows (I got them from this site [URL] ....)
**ClientMain.java**
import java.io.IOException; import java.net.Socket; public class ClientMain { private DirectoryTxr transmitter = null; Socket clientSocket = null;
[Code] ....
Note that:-
1. ClientMain.java and DirectoryTxr.java are the two classes under client application. 2. ServerMain.java and DirectoryRcr.java are the two classes under Server application. 3. run the ClientMain.java and ServerMain.java simultaneously
Also specify the source directory, destination directory and host address of the machine in which server is running in the ClientMain.java(as per your computer). Here we are not specifying source file ,instead a source directory or folder is specifying.So the entire files of source directory will be transferred.
I have an android device which i want to be able to switch off remotely from a console hosted on the amazon cloud.The console is a simple html button that on click sends a command to a listening server on an android device that i know its ip address.
My question,is this even possible given the huge security bleach this would present to rogue apps to be able to order actions on remote devices not started by the device owner?.
The way i know the ip is via once internet is connected on an android deice,i shall then make it announce its ip that it has been assigned by the service provider,then starting a server to accept external connections.
My theory could be wrong if what i want is not permitted.
I'm currently new to java and I would just like to ask if Socket is sufficient for this file transfer app I'm planning to work on.
The specs are as follows:
~ Move/Copy Files of selected folder/s to a single folder(consolidating them) within the same machine and Network ~ File type will be specified on GUI and those specified will be the ones transferred ~ option to choose Move or Copy of files ~ ability to create/select folder of transfer destination
I want to encrypt a file and decrypt it on another host. For decryption on another host I guess I need to transfer the cipher... how can this be done? How can you write a Cipher to disk?Or am I completely on a wron track?
The following code is doing it already on one host:
The problem is, the values are completely different than they are saved in MATLAB, and probably I need to shift the values after transforming them into byte arrays.My Java code which reads values of floating numbers from a MATLAB bin file as follows:
import java.io.*; import java.io.File; import javax.imageio.ImageIO; import java.nio.ByteBuffer; // may be useful? public class floatingNumberMatrixReader {
@ManagedBean @SessionScoped public class HelloBean { public void downloadFile() { File file = new File("C:datacontacts.doc"); HttpServletResponse response = (HttpServletResponse)
I have a txtfile which I read and go through. My question is what are the ways I could do to read a txtfile of words and assign an empty score to each of the word in it. So each word will have a 0 value. Later on I will manipulate the score but for now I want each word to have a 0 score.What I have at the moment is reading a text file full of words eg:
private void readtextfile() { try { Scanner rd = new Scanner( new File("filename")); List<String> lines = new ArrayList<String>(); while (sc.hasNextLine()) { lines.add(sc.nextLine());
[code]...
how to make each of the words to have a score of zero 0?
I am designing/coding a blackjack GUI program and I'm trying to add function to my JButtons. Problem is, I now have 2 NullPointerExceptions.
public class GameConsole { Player user; Player dealer; Deck playingDeck; ValidateInput validate = new ValidateInput();
[Code] .....
I am trying to do. I am getting the following exception/stack trace at line 14 in userTurn()
Exception in thread "main" java.lang.NullPointerException at blackjackControls.GameConsole.userTurn(GameConsole.java:163) at blackjackControls.GameConsole.gamePlay(GameConsole.java:87) at blackjackControls.Main.main(Main.java:7)
and then the program continues and after I click the button I get :
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException at blackjackControls.GameConsole.userTurn(GameConsole.java:163) at blackjackControls.ResultPanel$1.actionPerformed(ResultPanel.java:34) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2028) //and then about 30 more "at" lines
Why am I getting these exceptions and how do I fix it?
I designed a Java desktop application (i.e the app runs on local computer), everything is fine until when I compiled the program and wanted to run it on another computer then it tell me "java.sql.SQLException: attempt to write to only read database".
We are testing the newest release of JRE 1.6.0_85 (x86). We are running into an issue when Java launches through IE 10. We are seeing a command prompt window with the following message as soon as Java launches in IE 10:
Rejecting attempt to specify unsupported characters in command-line argument: -D java.security.manager
The window is labeled: C:Program Files (x86))Javajre6binjp2launcher.exe
The application using Java does launch and run correctly, but the command prompt window stays until the application is closed and Java is stopped.
If we add the URL for the website using java to our trusted sites in the local intranet zone and turn off protected mode for that zone, then the command prompt window does not display. This does not happen with the previous version of JRE (1.6.0_81). What has changed in this newest version? We do not want to turn off protected mode.
I have just started learning about sockets and such... and i have created a chat program with a server and a client
server:
public class Server { private static ServerSocket server; private static Socket connection; private static PrintWriter pw; private static BufferedReader br; private static JTextField textOutput;
[Code] ....
so, everything is working fine . There is only one thing i would like to do now: make it so that i can run the server from my computer and then others can run the client from theirs and we will be able to chat . So I tried:
In the client code on line 56 is says:
connection = new Socket("localhost",7777);
So I changed "localhost",7777 to "myip",7777)
But when i run the server on my computer and run the client on another computer i get this error:
Why is the connection getting refused? is it for security reasons? so hackers cant connect to me or something? And is there a way to tell your computer to allow that client to connect?
I am having a problem passing an int value from one class to the other. The gist of the objective of this program is to compute a local sum at each client, and then once the local sums are computed.. to compute the overall sum from all the clients. My problem is that I'm having trouble figuring out how to pass each sum from each individual client in the class multicastSenderReceiver to the readThread class. I keep getting an error.
I feel that I have to be able to pass the sum value from each client generated in multicastSenderReceiver to the other class, because that is the only way I'll accurately be able to sum up all the values..
I created an instant messenger using java. When I have the Server that communicates between the clients and one client running on my Computer the CPU Usage is at 100%. It really slows down everything else I'm doing and I figure this might be an issue if I gave this to people to use. I don't want the client taking up a lot of CPU Usage if they're just running it in the background while doing other things on their computer. The program utilizes multithreading. Each thread is constantly being polled for input.
The Server, as seen below, has two threads. I explain what the threads do before the code. There is also another while loop running constantly in the server that is waiting for sockets to connect. The loop does not run constantly at the line socket.accept(); it stops and just waits.
The User, split into a menu and chat window, has two threads as well. I explain what the threads do before the code. After I originally posted I put a 100 ms sleep in all my threads. CPU Usage is still at 100%*
This thread listens for input from the user. The input tells the server what action to take. There is a thread running for every user currently connected to the server.
public void run() { try { input = new DataInputStream(user.getSocket().getInputStream()); output = new DataOutputStream(user.getSocket().getOutputStream());
I have been practicing writing java code, my university course is going to cover socket programming and multi-threading.
I am presently just starting to write myself a framework for all multiplayer games I may make in the future, my aim really is simply to practice and understand better and this time, im not using an ide, just sublime text, all new grounds for me, I have a good basic understanding of the subject but I want to be fluent.
import java.net.*; import java.util.ArrayList; import java.io.*; /*SMOOTH THREAD SAFE MULTI CLIENT HANDLING CLASS. * *This class will create connection objects when a connection is detected, these connections will run in a separate thread and update an array list in their parent class containing their last sent data
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 have an application written in Java on the Linux platform. My application will work the following way:
User A will open application. User B will open application.User A will need to send User B a message but without a socket connection.User B will need to send User A a message but without a socket connection.The user should be able to identify the messages sent to each other.If User A reads user B's message the message will no longer be available in the channel of communication.If one user exits their application their message should be removed.User C should not be able to read user A and user B message (This is only via the application design, no real security here).Applications should be able to work on different machines however they will utilize a shared network mount to access files modified by each other.
I do have to note that the messages being sent is rather small and only 1 message is sent from each user, so in that regard I did not want to setup a client/server model to do this using sockets.
Basically I am looking for a similar concept as a message queue but more relevant to my requirements done in Java. What are some good options to use that will address some of my requirements? I have not touched Java in a long time and only have used it for certain usage so I am trying to get an idea of which current technologies are best for what I need.
