Servlets :: Send And Receive Object Between Client And Server
Jul 6, 2014
I write a Client/Server program,trying to send and receive a object between client and server. I use the ObjectStream but there exists an EOFException on the client side when invoking readObject() .... I've tried many times but couldn't figure it out ...
server-side code
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
try{
ObjectOutputStream out = new ObjectOutputStream(resp.getOutputStream());
ObjectInputStream in = new ObjectInputStream(req.getInputStream());
PersonalData pe = (PersonalData)in.readObject();
System.out.println(pe.getYearlySalary());
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 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'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 new to json and the web. My purpose is to use json data from a server and parse it and show meaningful data to the user. I am aware of json parsing, so no sweat there. However, I would like to know how json data is sent to the front end after which it can be parsed.
Usually in my json parsing examples, I have a variable like var data = ]OR I do a getJSON on a data.json file which I have stored in the project folder. However, I want this data to come real time from a servlet. How to go about this?
So, basically my question is, how do I send real time json data from a servlet backend, say some records which I have extracted from the database using jdbc?
I have written a program in JAVA which fetches an image from MYSql Database. I get a BLOB object then I am trying to convert that BLOB object to string; again I am using that object to write the image to a file. the image file is getting created in E: but it does display any image
I have just taken it upon myself to attempt to develop an application using java that will implement several features for my aircraft maintenance unit. I've taken a few courses in Java and I am a computer science major, so I wanted to use this as a way to improve my coding skills while also improving the effectiveness of my unit.
Anyway my application needs to have these key features:
1. Access a recall roster that is in Excel format and read the names/phone numbers of up to 200 members. The application also needs to be able to update this information and save it.
2. The application also needs to be able to initiate a recall to some or all of the members on the recall roster via text message.
3. The application needs to be able to receive messages back and display them under each name from the recall roster.
My current plan is to set up a GUI that expands JButtons in a scrollable window as members are read in from the excel document. Upon clicking any of the buttons the person will be contacted individually via a custom message that can be typed in via a popup window after clicking it. Alternatively you can check a box next to any persons button to add them to the list of people to be contacted and then click a button that says "Contact those checked" or something along those lines. Finally there will be a button that just says initiate total recall and it will contact everyone.
As for the interface I want each button to be highlighted red until a response has been received from the person associated with that button, which will then be recorded under their contact information.
I'm using netbeans to develop an application to send and receive data via RS 232 standard. I can send data but I can't read it.what can I do? I have this message in the console: Underlying input stream returned zero bytes. (I must use also threads to have application in real time but I don't understand very well....
I have programmed a Router class which has two methods, receive and send.In receive method it receives the plain text from the server through port 2000.Its now all cool.In send method it sends the message to a client through the port 2001 but at the client i get an exception
connection refused:connect import java.io.*; import java.util.*; import java.net.*; import java.sql.*; class Router { String str; public void receive()
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() {
Using Java 7 update 5 (I know it's old...), we are trying to send concurrent requests to a RMI Server. When we start to tamp up the load (not too much - up to 50 concurrent requests) we start to see many IO Problems like Broken Pipe and Connection Reset By Peer. Could we be hitting some unknown limitation on concurrent access? Is there such limitation?
I am working on a chess game. I need to construct a game room where all the player are present and room chat is up. Also some tables where games are being played. Now my question is how to create this game room?
To me this room must need to be like static or global (if I am not mistaken) that is up when server starts and players can join this room and should be down when server is done. How can I implement such room that would stay up for infinite time.
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'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 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.
