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 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.
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
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.
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.
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;
Our assignment is to make a version of the classic 'Connect Four' game, where we need to construct a GUI that shows the current state of the game and instead of having a winner once a player has four chips in a row, the game needs to continue until no chips can be placed anymore.We currently get stuck in the GUI part. Running it right now results in a board with empty spaces only. Also after choosing a column to place, the board remains empty.
Our question: How do we get the board filled with the right color of chips at the right place?We know the 'ArcsPanel'-class (almost at the bottom of the code) is wrong, but we don't know what to do to make it right.
I am trying to learn how to connect to web sites using java. Someone suggested that I learn to "consume an API with java". They also suggested that I practice through a weather website called weather underground and sent me a link [URL] .... I would like to know how to connect to this site to get weather information.
soo, is there a way to (via sockets or something like that) connect to a stream via the streamers url (or just via anything) and then get the actual stream? like the images that keeps updating? so that i can display the images/stream on a jframe?
How can I connect to an SSH server in Java? I don't need/want a shell. I just want to connect to the SSH server and get the content of, say, file.txt. How can I do that? Example : I get host, user,pass in txt and connect it with java code!
I have a vps set up to running a MySQL database already by zpanel but when I try to connect to the database with Java I am unable to connect and receive the message:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server."
I have MySQL Connector(dev.mysql.com/downloads/connector/j) already added to my build and tried it with both the url and the ip. This is my connection code:
package net; import java.sql.*; import javax.swing.JOptionPane; public class LoginDatabaseConnection { Connection conn = null;
[Code] ....
The code is from youtube but when I connect to localhost it works fine however when I try to connect to the VPS the above error happens.
I am a student in an intro to computer science class working on my final project. This is essentially a game of connect 4, but only requiring 3-in-a-row for victory. We were given the base game and a sample file to work with to make an AI that beats our professor's ai in the base game. Here is the base game
I am having a problem to connect my .exe file to the database(mysql). I used launch4j to convert the jar file to .exe but the jar file can connect to the database when running inside the dist folder. When I run the .exe I am getting this error: No suitable driver found for jdbc:mysql.
My code below is trying to make a connect four program without GUI. I'm having trouble with getting the players to make their moves. What should I put in my "makeAMove" method...
Java Code:
public class Connect
final static int MAXROW = 6; final static int MAXCOL = 7; public static void main(String[] args){
Whenever I enter a column number to drop a checker, the program immediately stops running and gives me a "java.lang.ArrayIndexOutOfBoundsException" and points to my checkWinner method. There are two int constants, one is LOWEST_ROW_INDEX = 5, and the other is RIGHTMOST_COLUMN_INDEX = 6. I cannot figure out what to do differently with my checking algorithm to stop this from happening.
public static String checkWinner(String[][] gb) { //tests for a horizontal line made by four of the same color checker for(int row = 0; row <= LOWEST_ROW_INDEX; row++) { for(int col = 0; col <= RIGHTMOST_COLUMN_INDEX; col++)
For the latest assignment, my instructor has asked us to create a program where we create lines of at least for integers and if the program registers there being four of the same integer horizontally, vertically, or diagonally it returns true. For example:
If the program doesn't see four integers of the same value anywhere, it is supposed to return false. I've got it so it returns true for the lines above, 6x6 lines of integers and lines where only four out of six+ integers are equal. However, I cannot get my code to return false if there are only three matching integers in a row/column/diagonal nor can I get the program to print out either true or false for lines that do not start at the top left corner. (i.e 2 3 1 1 1 1) For the former I get this error message:
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 4 at ConnectFour.is4Consecutive(ConnectFour.java:41) at ConnectFour.main(ConnectFour.java:32)
For the latter:
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 6 at ConnectFour.is4Consecutive(ConnectFour.java:43) at ConnectFour.main(ConnectFour.java:34)
The answer to fixing my code is probably something small or something that will make me wonder why I hadn't thought of it myself... Here is my code:
import java.util.Scanner; public class ConnectFour { private static Scanner sc; public static void main(String[] args) { sc = new Scanner(System.in); System.out.print("Enter the height: "); int h = sc.nextInt(); System.out.print("Enter the width: ");
For my job I would to develop a Java application which downloads some data from a webpage and then process them.
The problem is that I have to authenticate to a proxy server to connect to the internet. As I browsed on the net, there is a possible way for implementation.
Sometimes it works fine, but usually I get the following exception:
java.io.IOException: Unable to tunnel through proxy. Proxy returns "HTTP/1.1 407 Proxy Authentication Required" at sun.net.www.protocol.http.HttpURLConnection.doTunneling(HttpURLConnection.java:2083) at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:183) at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1511) at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1439) at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:254)
I don't understand what's the problem and why it's not persistent.
