Why Class Implementation Is Not Possible In Java
May 14, 2014Why Class implementation is not possible in java....
View RepliesWhy Class implementation is not possible in java....
View RepliesI want to use graphs in java. Is there any class in java for implementation of graph theory? I most create a graph and run DFS(Depth First Search) algorithm on that.
View Replies View RelatedSo it seems to reason that many JavaFX applications will want to dynamically change CSS styles. Is the best way to do this via the <node>.getStyleClass().add("classname")? The underlying data structure is an observable list. So lets say one has 5 styles that simply change the fill color of a circle to 5 different colors respectively. So if I have a condition in which I want to dynamically apply 1 of these 5 styles, the way I currently do this is by defining all 5 styles as strings in a list using a static initializer, then I call <node>.getStyleClass().removeAll(list), then getStyleClass().add("classname"). I do this to avoid adding the same style over and over and inflating the underlying list. Is this the correct way to manage dynamic CSS styles?
So I know there is a few different way to implement a splash screen. My app has definitely gotten larger over the last few months of development and I have noticed there is about a 5 second delay between when I run the application to when I see the main stage. I was thinking a splash screen would be nice to fill this time period. I have not had time to prototype using a Preloader and I fear that using an alternate, lightweight stage on startup would still take too long of a delay. I was actually thinking that using the nice and simple JVM argument "-splash:<image name>" would be simple, easy and effective. Unfortunately when I try to do this, the splash screen comes up but never goes away.
I tried using ScheduledService but the delay and period fields accepts a Duration object. I want the Service to run at exactly 6.00 pm everyday.
View Replies View RelatedNot necessarily Java related, more a general programming issue I have come a long and I am currently using java to mock up a project that will eventually get moved over to C++.
I am trying to implement FFT Convolution into a java project and have things partially working, I do not know if it is a coding issue, logic issue or if I simply know nothing of FFT and convolution.
For starters I got an FFT library that I do have working, if I create a small array pass it into the forward FFT, do a little bit of bit manipulation (converting a complex array of size n*2 into a re[] and im[] of size n), run the inverse FFT and do the same bit manipulation again I get back where I started.
However if I take two arrays, a Dirac Delta function (an array with a 1 followed by zeros for the rest of the array) and a stepping kernel (ex. {1, 2, 3, 4 etc}), I would expect to get the forward FFT of both arrays, bit manipulation, multiply them together, Inverse FFT, and bit manipulate again and the result would be the kernel. I have not had such luck.
This is the gist of the program:
// bit manipulation, converts complex array to two re and im arrays
public void bitTwiddle(double [] real, double [] real2, double [] imaginary){
double [] realCopy = new double [] {0, 0, 0, 0, 0, 0, 0, 0};
double [] imaginaryCopy = new double [] {0, 0, 0, 0, 0, 0, 0, 0};
for (int idx = 0; idx < (N * 2); idx++){
realCopy[idx] = real [idx];
[Code] ....
This is the result:
Quote
=====================================================================
Dirac Delta In Time Domain:
Real:1.000.000.000.00
Imag:0.000.000.000.00
=====================================================================
Dirac Delta Frequency Domain
Real:0.500.500.500.50
Imag:0.000.000.000.00
=====================================================================
Kernel In Time Domain
Real:1.002.003.004.00
Imag:0.000.000.000.00
=====================================================================
Kernel In Frequency Domain
Real:5.00-1.00-1.00-1.00
Imag:0.00-1.000.001.00
=====================================================================
Result: Dirac Delta x Kernel
Real:2.50-0.50-0.50-0.50
Imag:0.00-0.000.000.00
=====================================================================
Result In Time Domain
Real:0.501.501.501.50
Imag:0.000.000.00-0.00
how to start with decision table implementation in java
View Replies View RelatedCode for login page by java and how we can implement it.
View Replies View RelatedI have to implement all the stack methods in java such as push, pop empty, not using the ready methods but have to create them and to execute an exercise but is sth wrong with it
public class Stiva {
/** the problem is here how to declare the stack 1 and stack 2 and kreu(head) gjmax(size)*/
int Gjmax;
int array[] = new int[Gjmax];
int kreu;
private Stiva stiva1;
private Stiva stiva2;
[Code] .....
I have to implement all the stack methods in java such as push, pop empty, not using the ready methods but have to create them and to execute an exercise but something wrong with it....
public class Stiva {
/** the problem is here how to declare the stack 1 and stack 2 and kreu(head) gjmax(size)*/
int Gjmax;
int array[] = new int[Gjmax];
int kreu;
private Stiva stiva1;
private Stiva stiva2;
[Code] .....
How to implement non local means filter in java?
View Replies View RelatedWhat 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 want to implement the 2048 game in Java.
I made the game logics, but now I need to implement the interface.
I made 2 classes GameBox and ContainerBox that extends JComponent.
I painted in GameBox a rectangle and now I want to initialize a matrics of GameBoxes in ContainerBox so I used:
GameBox GB[][] = new GameBox[4][4];
I am thinking about drawing the Boxes in something like this:
for(int i=0;i<4;i++)
for(int j=0;j<4;j++)
but I don't know how to draw those rectangles in the for...
Does child class gets a copy of the methods and variables of parent class?
public class test1 {
public static void main(String a[]) {
Child c = new Child();
c.print();
[Code] ....
why is the output 1?
i want to write a class in such a way that i should get the current execution time of another class which is running. I searched in net but it shows only how to calculate the time duration of the current class which is running. But as per my way, i need the execution time of one class from another class. How to do this ?
View Replies View RelatedI am working on a calculator for Android.To make sure the application I am developing works with multiple operations (in the correct order) I decided to use ANTLR as part of my Java coding of the calculator. So in a separate file (.g4 file), I must declare the format of the expression.
E.G.
grammar Expr;
prog:(expr NEWLINE)* ;
expr:expr ('*'|'/') expr
|expr ('+'|'-') expr
|INT
|'(' expr ')'
;
NEWLINE : [
]+ ;
INT : [0-9]+ ;
After which I need to include the ANTLR class library in my Java Class. Then I believe I need to call a set of functions such as createLexerInterpreter and createParserInterpreter, but I am not sure. I will be having an algorithm string that will need to be parsed, such as " 3+4*5+8*9+(5/6) ".
I will give an example below of what I am talking about. in C++ I know I would need a copy constructor because I would be pointing blindly in the heap if I deleted a object in the struct.
We have a Class/struct animal and three animals in that class/struct, a dog, a cat and a cow. Each animal has a baby and then I will give the animal a name in main. But if I delete one of the dogs puppies because I sold him wouldn't I being pointing off in the heap and have a leak?
Also since Java doesn't have structs can I put a class inside a class?
1. In jsp 1 , i have 3 checkboxes(chkbox1,chkbox2,chkbox3) , if i select check boxes (chkbox1, chkbox2), and click on submit, corresponding two text fields (chkbox1,chkbox2) will have to appear in the next jsp i.e., jsp 2.
2. In jsp 1 , i have 3 checkboxes(chkbox1,chkbox2,chkbox3) , if i select check boxes (chkbox2, chkbox3), and click on submit, corresponding two text fields(chkbox2,chkbox3) will have to appear in the next jsp i.e., jsp 2.
Like this, which ever checkbox i select, corresponding text fields should appear in the subsequent jsp.
Its that very old question regarding hashcode and equals implementation which i am not getting .
import java.util.*;
public class MyElement {
public static void main(String a[]){
HashSet<Price> lhm = new HashSet<Price>();
lhm.add(new Price("Banana", 20));
lhm.add(new Price("Apple", 40));
[Code] .....
In the above program even if i comment out the Hashcode method , i believe it is still taking the memory address values from the native hashcode method of Object class. but the equals override implentation says that i have two insertions which are same . So as per my logic it should not allow the duplicate element to enter.but its not so ...the duplicate element is well inserted without hashcode .
How to implement GridLayout. In my applet, I want to make a grid of 2 rows and 2 columns. In each grid I want to add a Label and a TextField. I want the background to be red.
So my code would be?
import java.awt.*;
import java.applet.*;
import java.awt.event.*;
public class GridLayoutApplet extends Applet implements ActionListener{
// construct components
Label fNameLabel = new Label("First Name");
TextField fNameField = new TextField(20);
[Code] .....
I have read about panels and frames but, it is all confusing to me. How can you add a label and a TextField to one square of the grid?
Something about implementing Comparator interface isn't very clear to me: overriding the compare method.
Like here for example:
//This sorts a list of objects holding information based on age: the name and the age of the person
public class Person {
String name;
int age;
public Person (String name, int age)
{
this.name = name;
this.age = age;
[Code] ....
What exactly is happening behind the scenes? I don't understand mostly the part where it returns a 0, a 1, or a -1. After it returns one of those values, what really happens next?
For the displaying of the list, is the method toString() being accessed to output the list in the System.out.println statement?
For the generics, why do we use Person?
An abstract method is a method with no implementation. So would like to know what is the purpose of calling it if there is no implementation?
View Replies View RelatedThe following codes shows an implementation of an enqueue function of a FIFO immutable queue, and the output result shows the String "c".
I don't understand why since I expected it should be null.
The head and the tail of an ImmutableQueue Object are two separate queue, and each time I call the enqueue function, it just return a new object with a new tail, however, the head is not modified except the first two times I call the function.
Therefore, I expected head.next.next should be a null element, but the result is not like that.
public class ImmutableQueue<E> {
private int size =0;
public Queue<E> head;
public Queue<E> tail;
public ImmutableQueue(){}
private ImmutableQueue(Queue<E> hd, Queue<E> tl){
head=hd;
tail=tl;
[Code] ....
I want to implement new locking mechanism similar to like how threads locking or synchronized does the operation. Any inputs to implement out own locking mechanism ?
View Replies View RelatedI am in the process of implementing Priority queue, as I understand that there are many data structures you could use to implement. I implemented it with the an array, which it works absolutely fine. However I have limitations on what collections I can use from the collections classes. I fact I cant use any of the collections classes. Meaning I cant use array.
I’m trying to implement Priority Queue using heap. And implementing heap using binary trees. But however I have a few questions which I need to clarify and I cant think of any other way of resolving it. Ofcourse I can implement my own simple array class using linked list.
Inserting into heap would be quite simple, as I just need to find the right last position from left to right leaf to insert the node into the tree. However after inserting, you may want to make sure that leaf node values are > than root node. Therefore, the root node will always be with the highest priority.
I call these steps where you compare from top down as bubbledown and bubbleup. To do this I really need a for each node within the treee node to have attribute pointing to its root node. So in case of bubbleup I always have a pointer for a given node to its root, without it would mean I would to traverse through the entire tree to identify its root. Which I believe is very inefficient.
Or have I taken this completely wrong? Or is it the case that heap are only best with arrays and therefore use array (by implement it using linked list?)
I've found following code for Singleton Implementation from this forum, I am having a difficulty of understanding following,
1. When Singleton instance will be created, ( From which call ) ?
2. What feature of Static Inner class allow object to be singleton ?
3. How Inner Class implementation is thread safe ?
4. What will happen if variable "instance" mark as non-static, Will it still grantee singleton implementation ?
Java Code:
public class Singleton {
// Note private constructor
private Singleton() {}
private static class SingletonInner {
private final static Singleton instance = new Singleton();
}
public static Singleton getInstance() {
return SingletonInner.instance;
}
} mh_sh_highlight_all('java');
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.
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