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....
View Replieshow to send emotions in a chat application built in java using netbeans ?
View Replies View RelatedI 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've attached an extremely rough picture...
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());
[Code] .....
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()
[code]....
I got my first project in which i need to receive some data from multiple client on network regularly(say every second) and then process that data and stored it to the database and then GUI needs to be created which display data accordingly.
While thinking for the design i thought blocking queue to implement the same. Like producer receive data from the port into a string builder and put that into the LinkedBlockingQueue. Consumer will take this data , process some work on it and store it into the database.I am using sybase ase 15 as a database.
My question is as i am receiving data very frequently which require insertion , updation and search almost every second into the database. What is the best way to improve the performance.
say i have 2 types of data is coming one having keyword 'Alarm' and other having 'ceased' so i need to use something like this
common fields in both is name and number.
if (ceased)
search into the database for particular event for which this ceased receive using name and numbe rand update the another field into it Also make separate entry for it
else
make a entry
Also as i am using 2-3 thread for consumers and thread = Number of client for the producer. So i thought to use synchronization at the consumer side which writes data into the database such that only 1 thread can write it.
I haven't been able to find a cut and paste working example of how to receive MIDI data from a MIDI device, like my piano, and display something to System.out.There are all sorts of examples for synthesizers, sequencers and sending data to a MIDI device, but I have not been able to find a single example of how to receive MIDI data and just display a simple message.
I just need something simple that works to start playing with it, and understanding how it works. Having a working example would also support understanding the Sound API descriptions. They read like differential equations texts books to me, i.e. not clear at all.
I have a working example of how to poll all devices and getDevice.info, which is supposed to then be used to address a specific MIDI device.
I've also looked at a number of books, in the store and on line.I haven't seen a single example anywhere.the closest I found to working examples was on StackOverflow, but I didn't understand some of the other code in the examples, which may or may not have been working correctly anyway.
I would like to understand how does multipart/form-data works during file upload scenario's, Does it chunks the data from client to server while transferring the files ?
View Replies View RelatedI am working on a Java Web Server application.In which server needs to send message to a Mobile no?
What are the way to send message to a mobile no by Java application.
by reading online threads i found like
[URL]
which one I should use and any other approach other than these to send a message using java application?
how can I send a sms through java application?
View Replies View RelatedI have to send a request with post parameters from one web application to another web application,both are running different servers.
In my application i don't have any JSP,html only controller part which will handle request extract request parameters & based on request params i'll do a web service call.
My current requirement is based on request parameters i'll send request to another web application with received parameters.
I tried with sendRedirect() ,but it support only get() method.
how to proceed further.
I have a Java application this application sits on a Dedicated server and gets information about the machine and run commands on the machine.
I need it so that i can run these commands from pressing buttons on a website. For example i press a button to retrieve CPU info, it goes to the app, and the app sends the CPU info back.
I'm fine with the website and app its just the middle bit. How do i get the app to run commands sent from a webpage. Been ratting my brains for a couple weeks now.
Create a Java Application in NetBeans with the following two classes.
1. A Java class College
o Use the following data fields:
College Name
College City
Number of Tracks
Number of Students
Number of Faculty
Number of Staff
o Implement an empty constructor
o Implement a full constructor
o Implement Setters and Getters (Mutators and Accessors)
o Implement SetAll() method with all data members as parameters
2. Another Java class called CollegeDemo with the main() method:
o In the main():
o Read the values of the fields of 3 colleges from a text file and for
each create a College object.
Filename: colleges.txt
IT Dubai 7 200 50 20
ENG Abudhabi 4 400 60 20
SCIENCE Sharjah 3 300 40 20
First with empty constructor then uses setters.
Second with full constructor (no need to use setters).
Last one with empty constructor and SetAll() setter.
o Display the average number of students for all the 3 colleges.
o Change the value of ‘Number of Students’ in the SCIENCE College to
500, and display the average number of students again.
here my code :
public class Demo {
private String name ;
private String city;
private String cname ;
[code]....
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 am learning few concepts in servlets. And i came across this doubt. We used to send data over network using httpsession as below.
HttpSession session = request.getSession();
Object obj = new Object();
session.setAttribute("object", obj);
And get the data in JSP with below code
<%= session.getAttribute("object")%>
However I am not sure whether HTTPSession is serializable or not.
How HTTPSession works?
I am trying to connect to a local service over UDP - the simulator works fine, but my code does not... The sender is a separate thread and I have tried blocking, non-blocking, connecting, not connection, reading and re-reading the Oracle docs,
Java Code:
package my.comm;
import my.myMethods;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.DatagramChannel;
import java.util.LinkedList;
import java.util.Queue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
[code]....
I am not able to send large binary data from Java WebSocket client to Java WebSocket server. However, 1KB data transfer is working. Below is my code:
Client:
RandomAccessFile aFile = new RandomAccessFile
("c: est.txt", "r");
FileChannel inChannel = aFile.getChannel();
ByteBuffer buffer = ByteBuffer.allocate(1024);
while(inChannel.read(buffer) > 0)
{
session.getBasicRemote().sendBinary(buffer, false);
[code]...
Give me an example of WebSocket sample for large binary data transfer.
I'm creating a web applicaion. for that i want to create a registration page. and this registration details have to be stored in the database.
I'm getting the below error while trying to send the data ...
The requested resource (/cmd/InsertRegtodb) is not available.
Here cmd is project name and InsertRegtodb is servlet name.
Actually the servlet is present is the mentioned address. but it is not connecting to it
There is one more servlet in the same folder and which is accessible from another jsp. But this servlet is not accessible even though i have used same code as it is used for the servlet which worked for me previously...
How to modify and delete data from a array list in net-beans?
View Replies View RelatedI want to understand how is it possible to send data (image + text) along a single form. Here is my code:
<form method="post" action="updateAccount"
encType="multipart/form-data">
<input type="file" name="file" value="Select image ..." /> <input
type="submit" value="Start Upload" /> <br>
<textarea rows="8" cols="54" name="about">Yes
I have an application scoped and i want to edit it from request scoped data. I use this code but application scoped data are not updating. What i am doing wrong?
Application Scoped Data
@ManagedBean
@ApplicationScoped
public class ApplicationData {
protected String contactEmail;
public String getContactEmail() {
return contactEmail;
[Code] ....
What would be the most effective method to display data grabbed from a web source that is queried every second, for example the most recent EUR/USD price?
I already have access to the data stream, and I've built a simple FXML in javaFX that contains a grid; I'm not sure how to approach putting the live ticking data into the grid so it continues to update as the price changes, for example.
I have a tree-based data structure that looks somewhat like this:image1.png..Every tree always has a height of no more then 3, and each of these classes has a very specific use, generalization is not possible between them.Now, I want to display my data structure with a JTree in a Swing application. A JTree needs a TreeModel and so I created a custom TreeModel for my classes, it looks like this:
public class CustomTreeModel implements TreeModel {
private Root root;
public Object getRoot() {
return root;
[code]....
But then I would introduce this interface to my Model classes just for the purpose of writing the View. So my data model has to be altered to make the View work, this sounds completely against MVC to me and also like something I dont really like.On the other hand, the CustomTreeModel would be much simpler, easier to understand, easier to maintain and just in general more pleasing to the eye.Should I change my Model to improve the View? Is instanceof okay to be used in View classes?
I am trying to develop a new web application which takes in data from a form and stores data in a database.I have included all the three files join.jsp(the form which takes in data),reg.java(servlet) and JavaConncetDb(method which connects db and servlet). I get a 404 error when i try load the web application.
My file structure in eclipse
The error I am getting
join.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
[Code] .....
I want to create an application wich can handle xml files ( display xml files's data on a html page) + insert those data into an oracle database.
I'm new to that, it a project for my internship. wich API is the most appropriate for that ( Jdom or Xstream or other), wich framework i can use ( there is only 3 IHM : connexion, upload file, display data, confirmation insertion data)?
Code to receive a SMS using an USB dongle? or else how to write a code? I searched in the internet but couldn't find it.
I'm using Netbeans IDE.