Multimedia Application - Setting Constructor Of Subclass
Apr 30, 2014
I'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
The 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 ?
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;
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;
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 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");
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 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.
how 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;
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.
I am trying to put a reference to a given subclass object into a linked list, and then come back later, and invoke a method of the subclass object that is in a given spot in the linked list. This produces an error because Object does not have that method. Is it necessary to cast the object to the correct subclass every time I want to use one of its methods, or is there a way to convince the JVM to treat it as always of type MySubclass?
I have studied about the hierarchy of exception classes in which Throwable class comes at the top and two of its direct subclasses are Error and Exception..I just want to ask if in some code snippet we throw an instance of Error or its subclass within the try catch block then will that be also called "exception handling" ? I am asking this because Error class is not a child class of Exception therefore cant be said an Exception, therefore handling the same should not be called exception handling
convert or move standalone java thread application into Tomcat server container for accessing its JNDI services? Also is it possible to schedule this thread application in Tomcat server? is it possible to keep this app in tomcat as web application and schedule in window's scheduler.
I am new to work on JNLP program. I have created a SWING program, JNLP file when i deploy the ear file i am getting 404 error. Please find the steps in details.
1.Created a dynamic web project JWStartProject in eclipse
2.Create a HelloWorld.java class under default package.
import javax.swing.*; public class HelloWorld extends JFrame { private static final long serialVersionUID = 4968624166243565348L; private JLabel label = new JLabel("Hello Java Web START!"); public HelloWorld() { super("Jave Web Start Example"); this.setSize(350, 200); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE ); this.setLayout(null);
[Code] ....
Now I exported this project as JWStartProject.war contains following code.
Created Server in Websphere Admin console
Deployed this war file under the server and started.
I have added MIME types also.
I am unable to launch the application. I am getting 404 errors. May I know where I went wrong?
I was practicing my java skills and came across an exercise in which a non parameter constructor calls a two parameter constructor. I tried a few searches online but they all came back unsuccessful. This is the part I am working on:
public PairOfDice(int val1, int val2) { // Constructor. Creates a pair of dice that // are initially showing the values val1 and val2. die1 = val1; // Assign specified values die2 = val2; // to the instance variables. } public PairOfDice() { // Constructor that calls two parameter constructor }
I tried calling the two constructor using the line "this(val1, val2)" but I get an error because val1 and val2 are local variables.
Then I tried to use the same signature: "this(int val1, int val2)" but that didn't work either.
Here are two codes that I am using but I have one that just doesn't work for some reason and the other does. Encode doesn't work. I don't need the Character.isAlphabetic for encode but not sure what I can use with 'if' to set the String encodedString.
I have been playing around with a snippet I wrote to get the Label on a drive (below). It works fine for me (though I will take any constructive criticism). My question is whether the is a way to set the drive label, purely with Java. I know I could call command line, or even resort to using the Windows API
I tried using this since the jSpinner's minimum value is 1.. (I want it to reset the jSpinner after updating the database):
jSpinner1.setValue(new Integer(1));
But gives me an error:
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: -1 at java.util.Vector.elementData(Vector.java:730) at java.util.Vector.elementAt(Vector.java:473) at javax.swing.table.DefaultTableModel.getValueAt(DefaultTableModel.java:649) at shop.jSpinner1StateChanged(shop.java:267) at shop.access$100(shop.java:22) at shop$3.stateChanged(shop.java:145) at javax.swing.JSpinner.fireStateChanged(JSpinner.java:457)
JFrame{ JPanel(That MenuBar at the top) JPanel(That panel at center with table){ JScrollPane{ JTable } } }
I want to add my custom image to that grey space right there. I guess it is a JScrollPane, because I added that orange background on JPanel that contains it. But when I add this code to my custom class of JScrollPane:
@Override public void paintComponent(Graphics g) { super.paintComponent(g); if(background == null){ background = new ImageIcon(ClassLoader.getSystemResource("tableBg.png")).getImage(); } g.drawImage(background, 0, 0, null); }
The result is the same, no changes.
Then I read some documentation. I found this method:
scrollPane.getViewport().setBackground(Color c);
It works, but it accepts only color and I want to add image. Is there any way to do that? Do I need to subclass JViewport and use paintComponent ? If yes, then how to make getViewport() method return my custom subclassed version?
I have a PDF file and I have a text file that contains this data. It has the name of a PDF field along with a database table column name.
Text file: pdfFieldEmployee=Employee; pdfFieldStartDate=StartDate; pdfFieldSalary=Salary; pdfFieldExempt=Exempt
I also have this hash map that contains the database table column names along with their corresponding values:
Employee, Don Parker StartDate, 5/6/2000 Salary, $55000 Exempt, N
How would I read through the text file and the hash map and at the same time do this:
if the pdf field is equal to pdfFieldEmployee, then set pdfFieldEmployee equal to Don Parker. if the pdf field is equal to pdfFieldStartDate, then set pdfFieldStartDate equal to 5/6/2000.
and so on and so on. I would prefer to do this with a loop because I think it would take less code than writing a bunch of if statements.
This is my frame class, now I want to be able to change the name of the frame, and get the name with frame.getName() in another class. But I'm not sure how to do this, i tried making a new frame in that class but i feel it's just another frame and not the one i made, also tried something like
This is my code and it works! But how/where do I set a background image for it to appear as the background of my calculator? The code I have for it is this -
import javax.swing.*; import java.awt.*; import java.awt.event.*; /** * Program using SWING components to create a Christmas themed Calculator. */ public class ChristmasCalculator implements ActionListener
