Create Unique Constructors And Variables For Every Subclass
Sep 10, 2014
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.
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 ?
Say I have a class called ClassA which I want to hold my data. Now inside ClassA want to hold instances of a class lets call ClassB. So far we are here.
import blah.B public class A { private B myB; (Getters setters etc) public String getBString() { B.getString(); } }
However I want to have multiple extensions of ClassB which have UNIQUE static variables.
public class B-1 extends B { private static String mString; private static int mInt; }
The problem I have run into is I can't have subclasses with their own static variables. I need the A class to hold any type of B class. How can I manage this?meant
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 have to create an application that deals with maps.
I first have to create the instance variables for the class.
So very simply if my hashmap is going to consist of football clubs and players. Football clubs being a string value for the key and players being a set of strings for the values. How would I go about creating the instance variable in a class for this?
I can't seem to find anything that specifically deals with instance variables and constructors for maps.
Create a class called Employee that includes three pieces of information as instance variables:
-Employee ID (string type) -first name (string type) (default value 'John') -last name (string type) (default value 'Smith') and -monthly salary (type double). -No argument constructor that initializes the three instance variables. The employee id should be generated using the following process:
The employee id should be a combination of first initial, last initial and a number starting from 10001 for the first employee and increasing by one for each employee. e.g. if John Smith is the first employee then its id will be JS10001 and if George Brown is the second employee then its id will be GB10002
-Provide get and set methods for each instance variable. The set method for monthly salary should ensure that its value remains positive - if an attempt is made to assign a negative value, leave the original value.
I am looking for a program to generate a unique alphanumerical identifier that is not too long; for example would start out with 6 digits like a licence plate or a postal code ex: AAA001 and use up all the possible combinations until 999ZZZ (just an example) and then when the possibilities are exhausted a 7th digit is added and so on. It matters not if they are sequential, the identifier just needs to be unique and not be too hard to remember (also i don't want to use ip adress or any personal identification). How I can accomplish this using java.
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.
Is it a good idea to use the date and time with the first or last few values of the session ID. Or should I just use the complete session ID value for my "unique id"?
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");
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'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
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 want a completely unique GUI with unique buttons, like I could make it a giraffe if I wanted to! (not going to, but a giraffe seemed like a pretty irregular shape) ....
I am attempting to count the unique strings (a.k.a flowers) in the array along with a count of any duplicates. An example is embedded in my code below. I've only pasted the part of the program I am having trouble with. I can't figure out what I am doing incorrectly.
private void displayFlowers(String flowerPack[]) { // TODO: Display only the unique flowers along with a count of any duplicates /* * For example it should say
I'm planning to make a unique news app for android (maybe iOS later) and I am fairly experienced in Java. Im thinking to most likely use RSS feeds, but am unaware how to implement them into JAVA.
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 found out what my next java class project is, and i am trying to get a head start on it. It is a simple address book. it needs to have 4 choices that get cycled through until quit is chosen:
1. add business contact 2. add personal contact 3. display contacts 4. quit
I have made an abstract contact class with a personal subclass and business subclass(all 3 are required). they have all been made, with set/get methods(the wonders of encapsulation and polymorphism have finally hit home!). The main program needs to add a new subclass object when chosen, and it needs to accept and store contacts by type
So, i am figuring 2 object arraylists for business/personal.
My question is: how do you create an object without having a name for it already programmed? Does it even need to have a unique name, since it would be stored in a seperate index and/or arraylist?
Which string method to search a particular character in a string whether a particular character is there or not . Suppose my String is like............
String s = "Java.";
How I can find the character " . " in above string "Java." is present or not . What is the string method to search that "."
We have a customer requirement , need to generate a unique number(configurable) and it should not skip at any situation.
We have about 3- 4 modules where we need to generate. And update in some xyz table column each time. We are doing this as below approach.
We generate that number in separate transaction and that too in end of the business logic and then move to success page. But recently it got skipped due to time out error during updating .... the db usage is huge at some time and multi user doing operation which intern generate multiple number of this time.
But as DB is not responded and complete transaction is roll out and this number got skipped...
My requirement is to put in all unique strings and remove duplicates from the stack.The comparison has to be done only in Stacks.Use of any other Arrays ,Hash tables to store values or comparing is Prohibited.what is the minimum number of stacks required.
At our banking application , there is a requirements to send unique reference number for some payment transaction.How can I do this at Prod while we have three app servers and we don't have DB at our end (front end site)?
I need to know the procedure for detecting a Unique Hardware ID of any computer using Java. All I want to do is once the software application is installed should not get installed using the same key...In short I want to do license for my application.
