Here is my abstract Boat class.
public abstract class Boat{
private int height;
private int length;
private int width;
private double boatValue;
private double chargeRate;
private Owner owner;
public Owner getOwner() {
return owner;
[Code] ....
I have a class called Config, now I'm extending another class called FileConfiguration on that Config class. You can make instances of FileConfiguration and my class Config you can also make instances of it. Normally, I have an instance of FileConfiguration in my Config class, this instance is changed to different values in different methods for different jobs in my Config class. That instance of FileConfiguration is set to other instances of FileConfiguration in different methods.
I have a method that returns that specific instance of FileConfiguration. I want to get rid of the method and the instance of FileConfiguration in my config class, but then extend FileConfiguration. Now, how do I set the EXTENDED FileConfiguration to other instances of FileConfiguration like I usually do? I think that I shouldn't use this = other instances of FileConfiguration, then how do I do it?
I have a linked list of objects of a class I created called BaseballPlayer. I also have a Fielder and Pitcher class that extends BaseballPlayer. The linked list and list nodes accept elements of type BaseballPlayer. I put into the linked list both Fielder objects and Pitcher objects. The Pitcher class has a method that returns a float variable that is only found in the Pitcher class called EarnedRunAverage. However, in my main program it won't let me access the method. It says: The method getERavg() is undefined for the type BaseballPlayer. It does however, let me access methods in the super-class BaseballPlayer.
Here is main code and the Pitcher class code.
ListNode p = list.getFirst().next;
while(p!=null){
if(p.player instanceof Fielder){
sortedFielders.append(Integer.toString(p.player.getNum()) +',');
[Code]....
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?
This is a someway special question, because I am using jmonkeyEngine.
But the topic is simple:
I have 2 classes:
public class Spielbrett extends SimpleApplication {
public static void main(String[] args) {
Spielbrett app = new Spielbrett();
app.start();
}
@Override
public void simpleInitApp() {
[Code]...
as the main class and a second class for the chips:
public class Spielstein {
public Spatial stone;
public int player;
public int team;
private AssetManager assetManager = Spielstein.getAM(); //THIS IS THE PROBLEM
public Spielstein(int t_player, int t_team){
[Code]...
My problem is: I can't access getAM() from the first in the second class. If you know why I would be glad for an answer.
I'll start off by showing my full code:
Main class
import javax.swing.JFrame;
public class groupingTest {
public static void main (String[] args) {
groupWindow test = new groupWindow();
[Code]....
At the start of the groupWindow it turns yellow and it says "The serializable class groupWindow does not declare a static final serialVersionUID field of type long".
I'm learning about inheritance and part of my problem is to create an Order with methods, then an UpdateOrder where the total price is changed by adding four dollars to it, and then a main method displaying a few orders. I've copied all three below in order. My question is when I run the program it will display the totalprice() first for the second order followed by name, number, etc.what you override always displayed first regardless of the order you put them in? (The issue is at line 31 on the third code.)
import javax.swing.JOptionPane;
public class Order { //superclass
private String customerName;
private int customerNumber;
protected int quantityOrdered;
protected double unitPrice;
protected double totalPrice;
[code]....
I am new to java i dont understand the difference between the abstract and inheritance i mean we use the abstract class with extends with other class name ,even we do that same in the inheritance pls tell me main difference between abstract and inheritance...
View Replies View Relatedhow inheritence and exception work together ?? what are the rules ??
View Replies View RelatedIf I define a class which contains a few static fields, and then have a few classes who inherit this class, then all these classes would have the static field as well. Now my question is the following: would all those sub classes (and the base class itself) share the same object, or would each class have one object for all it's instances?
View Replies View RelatedI've tried to write a package and two classes this way:
<path>/pack/Aclass.java
Java Code: package pack;
public class Aclass<T> {
private T t;
public void set(T t) {
this.t = t;
[code]....
I am in an intro programming class and we got assigned a problem for creating a super class with about a dozen sub classes for generating a random word(via WordGetter class) and then comparing that word to a variety of different patterns(like: does the word contain "re"). We were given the super class which looks like this...
public class Pattern {
public boolean matches(String text) {
return true;
}
public String toString() {
return "(TRUE)";
[code]...
and from this class, we have to write subclasses that override those three methods. I am struggling to understand inheritance and I am not really sure where to even start. Here is the instructions for the first sub class we need to write...
"CONTAINS" SUBCLASS
Constructor: The constructor accepts a String named ‘letters’.
Matches: This pattern matches any text that contains at least one occurrence of each ‘letter’.
toString: produces the text “(CONTAINS <LETTERS>)” where <LETTERS> is the ‘letters’ string.
getLetters(): this method must return letters.
equals(Object): careful on this one. Two Contains are equal if they have the same letters (order is not relevant).
(Example):
Pattern p = new Contains(“re”);
boolean f1 = p.matches(“renew”); // f1 is true
boolean f2 = p.matches(“zoo”); // f2 is false
String s = p.toString(); // s is “(CONTAINS re)”
boolean f3 = p.equals(new Contains(“er”)); // f3 is true.. really..
The first is clear , new Person().printPerson(); displays Person but for the second : new Student().printPerson(); it accesses the Student constructor that points to the Person class => object. It builds the Person instance then goes back to the Student constuctor .Both methods are private and to my knowledge invisible one to the other , except that you cant run the the Person one because it's private so the only one in the Student class is the Student one . Guess it 's incorrect , but why ? (is because private methods cant be overriden and somehow the super class one always has priority ? , even if it's private?)
public class Test {
public static void main(String[] args) {
new Person().printPerson();
new Student().printPerson();
[code]....
If i have 2 classes, Top and ClassB which extends Top
public class Top {
String variable;
public Top(){
setVariable();
}
void setVariable(){
variable = "variable is initialized in Main Class";
[code]....
So what is happening when ClassB inherits from Top?I know that the B constructor is calling super, so does that mean its calling setVariable (in Top?) but as its overridden in ClassB, then that is whats being called and setting the String variable?
i was leaning inheritance and tried to implement it in Java.This is my base class vehicl.java
public class vehicle{
private int topSpeed;
private int cubicCap;
private String modelName;
private boolean hasAlloy;
[code]...
I also have a derived class called car.java.What i wanted to do in the derived class was that i wanted to override the constructor as well as the getInfo() method from the base class.I wanted to add an additional attribute to the car "numberSeats" and display tat too when the object to car class calls the getInfo() method .It showed an error "identifier required" when i tried to compile car.java program.
import java.util.Scanner;
public class car extends vehicle{
//int numberSeats;
//System.out.println("Enter the number of Seats");
Scanner numberSeats=new Scanner(System.in);
numberSeats=numberSeats.nextInt();
//System.out.println(numberSeats.nextInt());
[code]....
explain the errors that i get when i tried to compile car.java without using super keyword or without defining the constructor from the Car class ?
Design Patterns are one form of reuse. so is inheritance. what are the similarities and difference between them?
View Replies View RelatedI am writing small pieces of code to make sure I understand Java basics and I have the following.
package teams1;
public abstract class Team1{
private String sport = new String();
public abstract String getSport();
public abstract void setSport();
}
import teams1.*;
[Code] .....
It doesn't compile because sport is private in the super class, but I thought FootballTeam1 would inherit it's own copy of sport because it is extending Team1.
I have a working program, except that it does not calculate the credit hours and the financial aid. When I enter an input, it works, until it should show the student name, credit hours and financial aid. the error i get from the command is "Hours invalid for false student". Here is the program i think i might have the problem.
import java.text.DecimalFormat;
public abstract class Student
{
//initialise variables
String name;
int creditHrs;
[Code] .....
I am trying to figure out how I can most easily make it easier to make new types of units in my game. I have buildings and ships, and would like to know how I could make it easy to add new units. I have been recently told about interfaces, and have worked with inheritance a little bit.
What I would like to able to do is have it so that all of the variables and methods common to all ships could be stored in a superclass or interface, and same with the buildings. I would also like to be able to assign behaviours to the buildings and ships, maybe as interfaces, which could contain all of the methods and variables required for the functions of that ship or building.
For example, creating a new type of building that can shoot, build ships, and can regenerate nearby ships. So it would possible inherit all of the variables and methods common to all buildings, such as health, image, x, y, getX(), getY() etc. But it would then also gain the variables and methods essential for its functionality, such as shootRange, shoot(), regenRate, etc.
How could this best be achieved?
So I'm just a little unclear about this, but how would I call methods from the 'top' of an inheritance chain? I say 'top' because Object is the top... E.g.:
public class AClass {
public void myMethod() { ... }
}
public class BClass extends AClass {
public void myMethod() { ... }
}
public class CClass extends AClass {
public void myMethod() { ... }
}
Assuming that BClass.myMethod() completely overrides AClass.myMethod() (so that there is no call to super.myMethod() in BClass.myMethod()) How can I call AClass.myMethod() from CClass.myMethod()?
What is difference between Java Serialization with Inheritance (IS-A Relationship) and Java Serialization with Aggregation (HAS-A Relationship) ....
View Replies View Relatedwhat 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;
}
This is my assignment.
Identify how multiple inheritance is possible in Java with interfaces.
Write a java programme with appropriate classes to demonstrate the above.
Hint: both inheritance and interface concepts are necessary.
For the project name in netbeans, use your id and the name "assignment" separated by underscore,
E.g. 9876543_assignment
Every type of controllable object in my game is a type of Entity, and so extends Entity. This is broken down into Ship(s) and Structure(s). But I have different types of structures as well. The problem is that I use an ArrayList<Structure> to store all of a team's structures, but I need to be able to loop through that, and still be able to reference the subclasses of those structures.
For example, I have a JumpGate, which extends Structure. I need to be able to reference a particular JumpGate - as a JumpGate - and not as a Structure. However, the way that I cycle through all of the different types of structures is with an ArrayList<Structure>. I could get around this by having an ArrayList<JumpGate>, however, I would then need a seperate ArrayList for every type of Structure, which would get messy.
I've an interface with generic methods in it. I would like to have specialized methods in the sub types. While doing that I'm seeing the following warnings in eclipse.
class Sorter {
<E> void sort(E[] elements);
};
class StringSorter {
// This gives me a warning 'hiding' to 'sort'
<String> void sort(String[] elements) {
}
// Gives me an error "The method someCrap(String[]) in the type StringSorter is not applicable for the arguments (String[])"
void someCrap(String[] elements) {
}
};
I would like to understand why eclipse gives the above warnings and errors.
I have a SplitPane, which is inside another SplitPane in the same tree hierarchy of the Scene. When I set the CSS class of the outer SplitPane, it always overwrites all CSS Settings of the inner one. How can I prevent it, so that e.g. I can assign a red divider for the outer and a green one for the inner SplitPane.
I have defined the CSS with
<code> </code>