I am creating a set of 3 subclasses, 1 superclass, and an application. In my instructions it says to make set methods in my super and subclass by using dialog boxes. In the application you have 3 different arrays where you create objects and are supposed to call the methods from the subclasses to be used in the application. I don't know how to make the dialog boxes from my subclasses to show up in my application.
View RepliesThe super keyword when used explicitly in a subclass constructor must be the first statement but what about if i have a this(parameters) statements ? As the this one must also be the first statement... Does this means that i can have only one or the other ? What about when the super constructor is not explicit (aka implicit ) , can i use the this( parameters) in the same constructor ?
View Replies View Relatedhow to get access from variables in a super class or a subclass. Here is what I got:
1) I have a super class that is in Jar file, I created a link in Eclipse, I know that the link is created correctly, I am going to concentrate just in one variable, so I don’t have to put all the code here firstName; in the super class(the one that is define in the path)
public class CommissionEmployee {
// Field descriptor #6 Ljava/lang/String;
private java.lang.String firstName;
in my class i have 6 argument constructor
My application (e.g., the print dialog box) needs to support multiple languages (user selected either at starting application or by switch in code).
How can this be achieved under Windows 7, Enterprise (works OK under Linux). I have tried : E.g.,
Locale.setDefault( .. );
JComponent.setDefaultLocale(Locale.LANG);
Setting resource bundle
but to no avail. The application always inherit the Win 7 system locale.
I am trying to display the getCommands() method from my subclasses but I do not know how to cast them both. At the moment I can only display one animals getCommands() method.
public class Test {
public static void main(String[] args) {
Pet [] pet = new Pet[5];
pet[0] = new Dog("Scamp", 1, "run");
pet[1] = new Dog("Molly", 2, "fetch");
pet[2] = new Dog("Rover", 3, "dig");
[Code] ....
In vb.Net, when I do the code msgbox("hello world") and put it in a loop, it will execute that command and show a new messagebox for every time the code goes through the loop. I am wanting to do something similar with java but I'm afraid I don't know how.I know that the following code will display a messagebox as I am describing it
Java Code:
JOptionPane.showMessageDialog(null, "message", "title", 1); mh_sh_highlight_all('java');
But when put in a loop, it does two things:
1) It hangs the program
2) It will only display the first message box and when you press ok, the other message boxes will be disregarded and not displayed (I'm assuming because of the hang).
For some reason the two JOptionPane message boxes at the end of my code don't seem to open when I run the program.
package assg2.kevin;
import java.awt.HeadlessException;
import javax.swing.*;
import java.util.Arrays;
import java.util.Random;
public class Assg2Kevin {
[Code] ....
for my class we have to make a rock paper scissors game using GUI boxes. Everything is working fine I'm just having trouble displaying what the computer chose. In other words, after the user selects Rock, paper or scissors, the scoreboard just pops up displaying the score. Here's the last working program before I started tinkering with it.
// your code goes here
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Icon;
[Code].....
I am able to generate text boxes. But I need one specific thing in that:
Through a drop-down I should select a number and those many text boxes should get generated.
Suppose I selected 4 from the drop down list. Then on screen it should display:
Student 1: Textbox
Student2: Textbox
Student3: Textbox
Student4: Textbox
I am trying to use JTextField. I have windows 7.I have jdk 8u45. I am trying to use multiple text boxes. I have written the following code:
import javax.swing.*;
import java.awt.*;
class Avg5Nums{
int num1, num2, num3, num4, num5;
double Avg;
Avg5Nums(int val1, int val2, int val3, int val4, int val5) {
[Code] ....
I have a problem where I want to give each subclass of a certain class an index number (I don't care what index numbers are given, as long as there is a one-to-one relationship between subclasses and index numbers and the index numbers don't skip). This number will be used to sort the subclasses as an intermediate step to what I want to achieve. I know I could do this:
interface Superclass {
int index();
}
class Subclass implements Superclass {
int index() {
return 0; //or 1, or 2, ...
}
}
But this quickly gets tedious when I'm looking at lots of subclasses. Plus, there's the off chance that I could mess up and assign an index twice to two different subclasses by accident. Is there a better way to do this? I read about Annotations.
I am trying to prepare for the next installment Java course. I found a syllabus online from last year. All I'm trying to say is that I am not in this course but will be shortly. I tried the first project but I am having subclass issues. I want to access the getStock method in the Executive subclass from the client. I keep getting a cannot find symbol: method getStock from class Employee. I don't know why won't access Executive.
Main:
import java.util.*;
public class EmployeeClient extends Employee {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
//variables
String name = " ";
int totalSalary = 0;
int stock = 0;
[code].....
I'm having a difficult time running this piece of my program. I can't run the method findSmallest() in subclass NEW because I receive an error that says I have to declare the variable "smallest" as final, but then I won't be able to continue my code because "smallest" when I happen to use "smallest" again, it will always be set to 0.
package FindYourCourseGrades;
import java.util.Scanner;
public class FindYourGrades {
public static void main (String[] args){
int number = 0;
int counter = 0;
int sum = 0;
double average = 0;
double smallest = 0;
[code]...
There are a few things lacking in the TableView's keyboard navigation handlers. In tracing the code, the behavior is handled via TableViewBehavior and its super classes. If I want to augment that behavior, how do I do it?
Ideally, I would like to subclass TableViewBehavior, but I don't see how I can do it. This gets created in the TableViewSkin ctor:
public TableViewSkin(final TableView<T> tableView) {
super(tableView, new TableViewBehavior<T>(tableView));
...
}
but as you can see there is no factory method to create the behavior class. If there was, I could subclass TableViewSkin and override the factory method.
I have to write an example program to fill boxes most efficiently with bags. All bags are the same size. The boxes come in Large, Medium and Small. Large boxes hold 20 bags. Medium boxes hold 10 bags. Small boxes hold 5 bags. I am getting input from JOptionPane input dialog box and then parsing that input to an integer.
I have to fill the large and medium boxes completely. I am not sure how to do this without an if statement. I can use one, but we have not covered it in class, so I am skeptical about using one to solve the problem. If I just divide the input number with integer division, I'm not going to get the remainder, right? So I'm thinking that I can mod my input number by 20 (the number of bags the user inputs) and then mod that number by 10 and then mod that number by 5, would that work?
From what I can determine check boxes are applied in SWT to the first column only of a table.
final Table table_project = new Table(g3_tabfolder_projects, SWT.BORDER | SWT.CHECK);
However I require check boxes on all cells. I tried creating a table for each column (which gives me my check boxes) but as the number of enries are often numerous and thus require vertical scroll the tables become out of sync (and to the user that sync is important).
Before I knock up some code to try and synchronise the tables I just wanted to check any alternative approaches. The project is SWT based.
Set<? super TreeMap> s = new HashSet<SortedMap>();
SortedMap<String,String> sm = new TreeMap<String,String>();
TreeMap<String,String> tm = new TreeMap<String,String>();
s.add(sm); //This fails
s.add(tm);
Why does adding sorted map to a Set that allows ? super TreeMap and instantiated as such fail?
Suppose I have
class A {
public void speak() {
System.out.println("I am class A");
}
}
class B extends A{
public void speak() {
System.out.println("I am class B");
}
}
class C extends B{
public void speak() {
System.out.println("I am class C");
}
}
Why this doesn't work while A is a super type of B ?
public static void insertElements(List<? super B> list){
list.add(new A()); //not OK, why?
}
So far I thought that setting superclass member variables as protected would allow the subclasses to access them using this. and that this was a good approach. However now after further reading am finding that actually these variables are better set as private and then accessed by the subclasses using public method (getters and setters) or constructor.
So my question is do you recommend setting them as private instead of protected and what would be the best way to access these variables from the subclasses ?
I understand the basics of using the JOptionPane Message boxes, but how do i take the information that is entered and store it as a file, or print it. I'm in my 6th week of class, and this happens to be maintenance related.
import javax.swing.JOptionPane;
public class Example_Maintenance_System{
public static void main (String [] args) {
//Operator Name Input
String operator_name;
operator_name = JOptionPane.showInputDialog("Please scan your barcode");
[code]....
I am working on a project in which I have three box (as of now) and each box will have some color of balls. So I am storing them in a Map of String and List of String as mention below.
Map<String, List<String>> boxBallMap = new LinkedHashMap<String, List<String>>();
Data in the above map is like this -
Java Code:
{box1=[blue, red, orange]}
{box2=[blue, red]}
{box3=[blue, red, orange]} mh_sh_highlight_all('java'); ProblemStatement:-
Basis on the above input, I need to return a mapping which will be List<Map<String, String>>, let's say for above input, below mapping would be return as an output -
Java Code:
[{box1=blue, box2=red, box3=orange},
{box1=red, box3=blue},
{box1=orange, box2=blue, box3=red}] mh_sh_highlight_all('java');
Here if you see, each row has alternate color of balls for each box - meaning blue for box1, red for box2, orange for box3 in first row. I cannot have same color of balls in each row. So this combination is not possible as it has same color of balls for two boxes in one row.
Java Code: {box1=blue, box2=blue, box3=orange} mh_sh_highlight_all('java');
And also, in the second row, I won't use those balls which have been used in the first row for that box. In second row, box1 has red why? bcoz blue was already used in the first row for box1 and box3 has blue and no box2 in second row.
The output combination is getting generated basis on the input being passed as shown above.
I started with the below code -
Java Code:
List<String> balls1 = Arrays.asList("red", "blue", "orange");
List<String> balls2 = Arrays.asList("red", "blue");
List<String> balls3 = Arrays.asList("red", "blue", "orange");
Map<String, List<String>> maps = new LinkedHashMap<String, List<String>>();
[Code] ....
Below is my method in which the crux of logic should be there
Java Code:
private static List<Map<String, String>> generateMappings(Map<String, List<String>> map) {
return null;
} mh_sh_highlight_all('java');
Below algorithm might work but still not sure how should I fit this in the code -
- sort the boxes by the number of balls they have in it (ascending, from the smallest to the largest box).
- while there are colors left
- loop over the sorted list of boxes
- in each iteration pick a color from the box (if there is one left), that is not already picked in the current iteration (of the while loop)
I have a class called Sprite which extends its several subclasses. Therefore, there are a lot of different Sprite classes, the thing is however, most of those subclasses have unique types of variables which I want to only be included in those particular subclasses, not anywhere else. For instance, I might have a variable measuring distance in one subclass, and in another subclass there might be a height variable inherent. I don't want the first subclass to have both variables, neither the second or the main class. Because before I initialize my subclasses, I need to create the constructors of those subclasses in the main Sprite class first because it doesn't have the unique variables which those classes consist of. How do I prevent that? Now I have to create the unique constructors and variables for every subclass, when I only want them in their associated classes.
View Replies View RelatedI'm working on a program design for a multimedia application its really just a learning process for myself about exploring application development, however there is a slight hiccup in the class inheritance hierarchy I think, and I'm not really sure why.
The problem being I cant set the constructor of subclass AnimatIntervalKeyFrame to be structured the same way as of the constructor of super class AnimatKeyFrame
This is the error given of the constructor of the subclass
public AnimatIntervalKeyFrame(int id, String category, Text text, ImageView image, int x, int y, int width, int height){
required: int,String,Text,ImageView,int,int,int,int
found: no arguments
[Code] ....
package multimediasoftware.appComponent;
import javafx.scene.image.ImageView;
import javafx.scene.text.Text;
// notes
// class is declared abstract
public abstract class AppComponent {
// variables
[Code] .....
I want to make an application and must use strategy pattern my idea is to create a super class in this case Movie Player and three sub classer and they'll komminesera with each other using strattegy pattern, one of the sub classes is Button Panel and I want to add it to Movie Player and it was to be its child,so how can I add the butt panel to Movie Player and it shall be its children?
MoviePlayer:
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import com.github.sarxos.webcam.WebcamPanel;
[code]....
what does super(); do in the following method, I understand its uses to access variables belonging to the superclass but i am unsure of what that one line does. Here is a sample constructor..
public CreditCard()
{
// fill in the default constructor and use the super call
super();
id = "000000";
year = 0;
}
How to create text fields, labels and input boxes on a GUI, we haven't covered these in class as of yet, but I want my project to stand out so I'd like to know how to build a GUI now.
View Replies View Related