I am writing a simple program to simulate a traffic light. What I want is to make them glow after each 1 second, one by one. For example: Firstly Red, then after 10 seconds, red will be put to off and yellow will start glowing and then accordingly green. This process shall continue incessantly (Just for experimental purpose). I have some arrangement done but could not figure out how to put them together in run() method of Runnable interface. I know how interthread communication works. But could not find any logic in this case when three threads will run together.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class TrafficLight extends JFrame implements Runnable
{
JButton red, green, yellow ;
TrafficLight()
I have a TrafficLightsManager Thread class that create one new CarTrafficLight object, and manage him by synchronized semaphore.
Unfortunetly the line sleep(5000); after the traffic1.WaitToRed(); never happenned, and the class jumps very quickly over the Red State.
I added the Message "!!!" before moving out from the Red State to the orange to check if the red exists at all and the result was positive - the red status entered and then I got the "!!!" message,but at the second that I accepting the message the red state turns into the orange state......
I don't get it!!!
package MyTzomet; import java.awt.Point; import javax.swing.JOptionPane; public class TrafficLightsManager extends Thread { CarTrafficLight traffic1; ViewFrame frm;
I'm a student designing and developing an Air Traffic Control (ATC) system for incoming aircraft, mainly implementing the part which handles the queuing system for approaching aircraft.
I'm writing a java program with opengl and I'm trying to get it where the user would select something like lighting on in a JMenu and then it would turn the lighting on in the house/barn... I have a method called LightOn that I put gl.glEnable(gl.GL_LIGHT0); but it just doesn't seem to turn on when I call it from the action performed... Is there something I'm missing from my code that I'm supposed to use instead since I have tried it with a boolean.. So the boolean starts off as false and when the JMenuItem is clicked the actionPerformed will turn the boolean to true and call the method LightOn. In the display method I have what the light is supposed to be
I am doing a multi threading program . I am unable to get the output i want. I have no compilation error . But I cant get the result I , Null exception. This is my Test program
import java.util.*; public class Test { public static void main (String[]args){ int totalShares = 0 ; double totalCost = 0.0; String name = "FCS"; double profit = 0.0;
This is my own coding for understanding deadlock in multithreading . But my doubt is whether this program mirrors the concept of deadlock perfectly or not. If not what should i do to make this code a perfect deadlock.
import java.io.*;
class A { B bc; synchronized void funcA(B b) { bc=b; System.out.println("INSIDE FIRST OBJECTS MONITOR");
I need to work with multiple threads in background in a JavaFX application. I have a screen with ten buttons and I need to 'bind' each thread with the button that started the thread. If the user pressed a button that had started a thread (in the main screen, MainController.java), I need to recover it to display the information that contains to display it on the controls of Details Screen ( a second screen, DetailController.java).
What Class do you recommend for this? Service?
[URL] ....
It is possible to name the threads with any of these classes?
If I have a web page with a lot of data to show, say a lot of tables and graphics, would using non JSP based frameworks result in a lot more individual AJAX requests? For example if the page have 5 tables, with JSP the whole page will be returned to the browser with data for all 5 tables already. But if this is a pure HTML / Javascript based view, then we need to have each of the 5 tables to make individual AJAX requests in order to render the page. Is this indeed the down side for not using JSP?
The reason I'm asking is because I'm considering moving away from JSP to a template based framework such as Thymeleaf or Freemarker.
I have a java application which uses Google Maps to analyze the traffic condition. But sometimes it can be run and work properly, sometimes not. On some computers on which there is installed java, the program can be run, and on some, again with installed java (jre), exactly the same version, the program can not be run. For example the application first run well on my desktop computer, connected in a LAN, and then stopped working well when run. But when I use laptop which uses the WiFi and run the same computer using VMWare, if I connect to the desktop on which the program can not be run, on the laptop the same program can be run well, in the same room, but using the Wifi.
I have a program that records and reruns network traffic. It was developed in C and runs in my case under Windows 7 Professional but will run almost anywhere. I have observed a lack of stability.
First I have a JAVA stand alone GUI program that runs the program as follows:
g11_bttn_start_script_capture.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(SelectionEvent e) {
I got a question in my last interview, its all about multithreading, interviewer asked me to write a program, to write the contents of three files(F1,F2,F3) in to a new File F4, using multithreading , first thread should read the first file and second thread should read second file, so the File F4 should contain F1's contents in first then F2's contents after that etc. I tried to give my best shot, but i couldn't get a way to ensure that the first thread is reading the first file and write to F4 then second thread reading the second file and writing once first file is written completely into F4 and so on ..how to do this?
I was thinking to make a game where two cars are going to race against each other. I already have two gif pictures which are the cars. I do now have a background and a racer track. So we can start from here.
I have made a object with construction which I called Racers. Inside that, i wrote a PaintWindow (Where the window and much more is inside), -car1, -car2. All these is private. So I made something like this now:
package p2; public class Race { private Object window; private Car car1; private Car car2; public Race(PaintWindow window, Car c1, Car c2) {
[Code] .....
But the problem is now that im kinda lost and I dont really know what to write anymore. How can I get a for example a green background on the whole PaintWindow with two Racers tracks and inside the racers tracks (Each car have each track) does it have to be cars. So I need to somehow import the cars inside it too. But thats the problem I need. that I dont really know what more to do. To make it easier, I have a Main-method in another class.
public static void main(String[] args) { PaintWindow window = new PaintWindow(); Car c1 = new Car(new ImageIcon("C:/Users/Sarah/Desktop/CarBlue.GIF")); Car c2 = new Car(new ImageIcon("C:Users/Sarah/Desktop/CarRed.GIF")); Race race = new Race(window,c1,c2); race.action(); if(args.length>0) { Paintwindow.pause(2000); window.dispose();
I'd like to learn more in Java security, namly Kerberos and SSO. The question is weather I have too weak laptop. I have 8 GB ram. How many virtualbox instances od I have to run in order to JAAS, SSO kerberos demo to simulate. For instance VM with Windows 2008 Server -> 3 GB RAM, Centos VM -> 1GB. Is 8 GB RAM in my laptop not too little?
BTW
I do not have yet experience in SSO/Kreberos but I want to know what to do in order to simulate and exercise.
I have a class "ExecuteJob" which has Print Q in the form of Priority Q.
You can keep adding job to the Q by calling one of the method in the class. However, and object cant do things simultaneity can it? While im adding a new job to the print queue, can it be executing and existing job in the print Q.
To achieve that, I would need to implement process and threads? I believe am I right? So that adding a job is independent to being removed?
So what I want to do is have a method that allows me to use the callRandomNumber method so that the matrix location with that random value is marked true for all of the boards.
I'm very new to Java (I literally started learning it yesterday) and I've been working on a simple program that's meant to simulate interactions between optics objects and light rays.
Everything has been going really well, except that my mirrors only reflect the first ray that comes in contact with them.
Here's a screenshot : 2014-09-13 at 7.39.23 PM.jpg
I wrote 7 classes:
Main class to create the optics objectOptics class. the most important class that uses a recursive function to detect the nearest intersection point of a ray with the nearest optics object. It then calculates a reflected ray and inputs it back into the function until no intersections are found or the max recursion depth is met.Ray. creates a rays (in parametric form O + tD where O is the origin, D is the direction and t is a non-negative scalar)Object. empty abstract class used for polymorphism (so when i add more optics objects like prisms and lenses they'll share the object type)Mirror. Basically a line segment created with the Line classLine. Creates a line segmentDraw. JComponent with paintComponent function that loops through an array of shapes and draws them to the screen.
What I know so far is that the problem boils down to the checkRay() function in the Optics class. When a mirror has already reflected a ray, the line:
Intersection sec = new Intersection(ray,(Mirror)obj);
creates an intersection with a null point.
I debugged it line by line and found the problem was that my variable 't' (that is the parameter for the parametric line which represents the mirror) in the Intersection class got big values when it's meant to be between 0 and 1 (since it's a line segment), which resulted in the function returning null (as it should when 't' is not between 0 and 1).
I've confirmed with tests that this has nothing to do with the specific mirror or angle of incidence. It only occurs when a mirror has already been intersected with by a ray.
I've found out that my function:
public PVector getNormal(PVector D){ D.normalize(); return new PVector(D.y,-D.x); }
Changes the value of the 'D' PVector of the mirror inside my 'objects' ArrayList. How can it access the private PVector 'D' from outside the Mirror class? This normalization to the direction vector is what causes the Intersection class to return null the second time around!
The problem was that in the getNormal function, the input vector argument was a reference to the 'D' vector for the mirror in my 'objects' ArrayList so the .normalize() function acted upon the original vector, changing it's value and screwing things up. The two classes I talked about:
Optics: (note line 64. this line returns a null intersection when it shouldn't)
package ofer.davidson; import java.util.ArrayList; public class Optics { //Arrays to store all the optics objects and rays that are created ArrayList<Object> objects; ArrayList<Ray> rays;
I am making a elevator simulator for my class. It needs to be "event time". I am having trouble understanding how I can make an "event time" simulator. Initially I was using a while loop to run a clock time simulation of x seconds for each event, until I ran into a concrete wall and had to call another method which took X seconds, while still needing to execute code.
An example of what I did is:
Spawn person -> person.goToElevator (Takes x seconds) - > person.waitForElevator (Until elevator arrives, x seconds). While this is happening, I needed to create another person and do the same thing, this will add another to the queue if the first person is still waiting. Etc etc, you get the point.
We have not learnt about multi threading, that is the next assignment.
Here is a quote from my lecturer:
"That's right, it requires multi-threading which we're not doing in this paper. Here's a solution that can work:
The person waiting for the lift and then doing lots of other things should do all that in a fraction of a second. So, you don't let the person really wait. Instead, you will set a timestamp in the future in the person object that "he's busy till that time". In all other steps in your simulation you will first check if a person is "busy" (i.e. has a timestamp in the future). If so, you can't use this object, otherwise, you can.
How does it create a bigger queue? Outputs I would have in my final simulation would be, averageQueueLength, numOfPeopleInBuilding etc.
I am attempting to create a 2d game that has a realistic space simulation. The map is supposed to be set so that you are looking from the top down. The problem I am having exists in my interaction between the sun and a planet. Simply put, the planet will only move in a single diagonal direction without ever changing direction. The formulas I am using are F=(G*M1*M2)/D^2 and A=F/M. The code below is simplified.
Things I have already tried: 1. Setting G to negative 2. changing the order of the subtraction in determining D 3. some weird pythagorean theorem thing someone suggested
how to setup a program that simulates the progression of a line over time.The scenario involves a bank and 5 tellers. There is one line of customers that starts off with an initial length of 20. Every minute, 10 more customers are added to the line. As this is meant to be a FIFO queue the first 11 customers in the line will be distrusted among the 5 bank tellers as follows: Teller #1 will process 1 customer per minute, Teller #2 and #3 can each process 2 customers per minute, and Teller #4 and #5 can each process 3 customers per minute. Therefore, the first 11 customers in line will be processed within the first minute of the programs execution.
Unfortunately, I am not sure how to attack this thing. I am thinking that I need to setup a queue for the initial 20 customers and an array for the 10 customers that will be joining the line every minute. However, I am not sure how I can set this up to work automatically.
