Suppose I have a base class B, and a derived class D. I wish to have a method foo() within my base class that returns a new object of whatever ... |
What are good reasons to prohibit inheritance in Java, for example by using final classes or classes using a single, private parameterless constructor? What are good reasons of making a method ... |
Hullo all,
Wondering if there are any Java hackers who can clue me in at to why the following doesn't work:
public class Parent {
public Parent copy() {
...
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Is there any other method of stopping inheritance of a class apart from declaring it as final or by declaring its constructor as private?
|
I have a question about inheritance and casting in Java. I have the following two example classes and a test class, and I state my question after the classes:
public class Automobile ...
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There is a Checkstyle rule DesignForExtension. It says: if you have a public/protected method which is not abstract nor final nor empty it is not "designed for ... |
what are the differences of Inheritance & java Beans?
|
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Let's say I have an animal and now I want to make it a dog. How do I go about doing this in java?
Right now I have a constructor that looks ... |
In a project at work we have a certain value type class in our domain model that includes a very large number of attributes...
public class BigValueType {
private ...
|
I Have something similar to this setup:
public class Base {
public String getApple() {return "base apple"};
}
public class Extended extends Base{
public String getApple() {return "extended ...
|
Running this code:
class A { ...
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class A {
public void talk(){
this.sayIt();
}
private void sayIt(){
System.out.println("class A says...");
}
}
class B extends A {
private void sayIt(){
System.out.println("class B says...");
}
}
B b = new B();
b.talk()
//output
class A says...
I cannot get this since:
Class ... |
When a class implements an interface, do the subclasses inherit the implemented interfaces too? For example
class A implements Runnable
{
public void run()
{
...
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package package.b;
class ClassB {
public ClassB(BaseClass bc, XMLBase obj1) { }
}
import package.b.ClassB;
class A extends BaseClass {
public void function() {
TestXML obj1 ...
|
Possible Duplicate:
add values to enum
Why enums in Java cannot inherit from other enums? Why is this implemented this way?
|
I have a question regarding inheritance in Java. If I have this base class
class Parent {
private String lastName;
public Parent() {
...
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I got this from a berkley cs data structures webcast:
class A {
void f() {System.out.println("A.f");}
void g() {f();}
// static void g(A y) {y.f();}
}
class B extends A {
...
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- A class in Java cannot extend more than one class.
- Every class in Java extends java.lang.Object .
- From 1 and 2: Any class in Java cannot extend any other class other than java.lang.Object.
What ... |
I have a class CommonTableModel that has several instance methods and each operate on the two instance variables
Now, I have six tables, each has diff. column names but should have all ... |
I have 5 different tables in a database. I have written an abstract "Converter.java" class that take out data from the database and convert it into a "tree.xml" file.
Tree.xml
<?xml version="1.0" standalone="no"?>
<tree>
...
|
I have a Parent.java class and 4 child classes as Child1.java, Child2.java and so on.
There are two methods
and one field
Field f1 has different values based on the child class.
Method m1 has ... |
I am trying to secure my Flex application within my Java web application. Currently my Java web application, handles logging and managing user accounts and the like. I was ... |
What if I have few factory methods returning non-public type and pairing set of methods which gives variables of this non-public type? This results with titled warning message in NetBeans.
In result ... |
If I have an abstract class in java named Foo and it has an implementor named Bar then I want to know the following.
lets say Foo looks something like
public abstract ...
|
recently I went through the inheritance concept.
As we all know, in inheritance, superclass objects are created/initialized prior to subclass objects. So if we create an object of ... |
I have a base class called Items and 3 derived classes, and within the Items base class i have a print function of the form
public void print(){
...
|
I'm writing a spatial data structure and I have a doubt about what's the best NODE implementation.
According to my design I have an abstract node entity and three classes which inherit ... |
Please explain me below situation
What would be the output?
interface A{}
class B implements A{}
class C extends B{}
class D extends C{}
class E extends D{
public static void main(String args[]){
C c = new C();
B b ... |
I am just refreshing the oops features of the java. So, I have a little confusion regarding inheritance concept. For that I have a following sample code :
class Super{
...
|
Can anyone explain disadvantage of inheritance in java
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I was looking at a blog about good API design link text
In one of the example sections titled 'Reinventing the Socket', it showed a design of how to enforce ... |
Suppose there is a business function you need to implement, which sets some kind of a profile.
Depending on how data is received, however, setting profile will be implemented differently.
For instance parameters ... |
Is it possible to extend the Math class and still use the Math class to call the extended method?
For example, I have a method public static double mean (LinkedList<? extends Number) ... |
Inheritance.java
public class InheritanceExample {
static public void main(String[] args){
Cat c = new Cat();
System.out.println(c.speak());
Dog d = new Dog();
...
|
So I've been trying to find the proper way to get what should be pretty straightforward inheritance to function (the way I want ;)) and I'm failing miserably. Consider this:
class ...
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Given:
class TestA {
public void start() { System.out.println(”TestA”); }
}
public class TestB extends TestA {
public void start() { System.out.println(”TestB”); }
public static ...
|
Hello I am new to java code (but not code in general) and the whole generics thing is kinda throwing me for a loop, and more so the RTT.
Specificis? Ah ... |
public class Person{
private String name;
private String surname;
private int age;
private String address;
Person(String n, String s, int a, String i){
name = n;
...
|
I working on an application as an hobby project. It is written in Java and part of a system to calculate decompression scheme for scuba diving.
The problem I have is in ... |
I'd be very grateful if someone could help me to understand the inheritance concept in Java.
Is the following code an example of that?
I mean the class WavPanel is actually a subclass ... |
I work for a small software development team, working primarily in Java, for a very large company. Our new intern showed up sight-unseen (not uncommon in my company). He ... |
Are there any best practices regarding the maximum depth of the inheritance hierarchy for a framework and guidelines when to use multiple levels of inheritance or join them in a single ... |
I have two classes :
public abstract class Arguments {
public List execute() {
// do some stuff and return a list
...
|
I can't figure out how to compile my subclass even though it calls the superclasses constructor?
This is the class that won't compile:
package departments;
import employees.*;
public class DepartmentEmployee extends Employee{
...
|
if I have an abstract class named Dog with a constructor to set its weight (double) and a class named SpecialDog which extends Dog and has a constructor that accepts a ... |
Ok, so this has been messing with me. (double entendre?)
ignoring variable types since that's not the issue
Lets say you have a parent class, for example a book class, with variable ISBN. ... |
I'm beginner in OO technologies, so i apologies if i have some dummy questions.
I have some confusion about inheritance and this keyword in java.
For example, suppose that we have next situation: ... |
Good evening everyone,
I have 3 classes:
- Error
- ShellError
- WebError
where
ShellError extends Error
and
WebError extends Error
In ShellError there are fields some of which are optional and others are required. I am building the object in ... |
Given these classes:
class Father {
public Father getMe() {
return this;
}
}
class Child extends Father { .. }
I'm calling the public method of the Father class ... |
What are some alternatives to inheritance?
|
I have a strange problem with inheritance and I don't understand why it should not work:
public interface A { }
public interface B extends A {}
public class C {
void test() {
...
|
I was reading about how java avoids the deadly diamond of death, but i still have some questions. What if a class inherits a class and implements an interface and ... |
Ok so this is the KernelHandler Class
public class KernelHandler extends ImageHandler
I'm getting a cannot find method getWidth()
I know it has something to do with inheritance, but I need help, please
//Heres the ... |
Ok so this is the KernelHandler Class
getWidth() is a method of the BufferedImage Class
public class KernelHandler extends ImageHandler
I'm getting a cannot find method getWidth()
I know it has something to do with ... |
I have a abstract Parent class that has multiple children. I'd like the child to be able to have a variable that is the same for every instance of that child. ... |
We're trying to implement some sort of Chess game and we have defined an abstract class Piece with constructor:
public Piece(String name) throws EmptyStringException{
if(name.length()<=0)
...
|
Why we can not extend more than one class in java?
can anyone clearify this point please.
|
A class C has a void method m with no parameters. Another class D extends C and overrides m. Each class has a constructor with no parameters. In each of the ... |
I have a string (which is a message) that I get as input and I need to do one of 4 possible things depending on the string
I know that there is ... |
Class-based inheritance shows its usefulness in creating big programming systems, especially GUI systems.
How can be applied Prototypical-based inheritance in real life applications? How we should build system instead of creating classes ... |
This is a simple Java code:
public class JTest {
public static void main(String []args) {
Integer a = new Integer(2);
...
|
Below is the example for Inheritance
class parent
{
parent()
{
}
parent(int a,int b)
{
...
|
Greetings. I've completed a project for school with all but one requirement.
The requirement is:
Notice that the SeaCreature class defines four constants for the various directions. Make sure to use them.Your code ... |
I'm having trouble casting a List of Fruit, down to the Fruit subclass contained in the List.
public class Response {
private List<Fruit> mFruitList;
...
|
Say I extend a class and override a method in this class. Why is it bad practice to then call the overridden method from the constructor of my new class?
|
The title pretty much explains the question. I have an interface method:
Set<Field> getFieldSet()
and I have a class, User which looks something like this
class User {
enum Fields implements ...
|
I have code like:
class Entity;
class EntityTool extends Entity;
class EntitySprite extends Entity;
class EntityToolSpoon extends EntityTool;
class EntityToolBow extends EntityTool;
class EntitySpritePlayer extends EntitySprite;
class EntitySpriteMonster extends EntitySprite;
Now I have a method called move() in Entity, ... |
I have 4 different classes with a common superlass called WebService that each have the following enums declared in them (with different values):
public class GeoPlacesService extends WebService {
public enum RequestParam {
...
|
While exploring for scjp questions, I came across this behaviour which I found strange.
I have declared two classes Item and Bolt as follows:
class Item {
int cost = 20;
public int getCost() {
...
|
What exactly happens when you create a new instance using :
Base b = new Derived();
I cannot really understand the mechanics behind this.
|
I ran into this example about inheritances on the web, and I am not easy regarding its results. I'm missing something critical.
public class A {
int i = 5;
public A() {
...
|
I implemented the Following:
public class MultiMapClass<K,V> implements MultiMap<K,V> {
private Map<K, TreeSet<V>> multiMap= new HashMap<K,TreeSet<V>>();
public MultiMapClass(){
}
public void put(K key, V value){
...
|
I have a parent class class A and a child class class C extends A.
A a=new A();
C c=(C)a;
This gives me error. Why?
Also if my code is
A a=new A();
C c=new C();
c=(C)a;
This works ... |
I have some problems with getting inheritance to work. In the parent class, the array Coefficients is private. I have some access methods but I still can't get it to work.
import ...
|
Guys can you please explain to me how come the output of this example is:
Exam1
This is Tennis Shoes
derived class
This is a white Tennis ...
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Okay so I've been set an assignment from university and I just can't get my head around how this problem, I'm the only person in the class that's got this far ... |
I'm preparing to interview and think that would be good if my answer for the question like "Explain inheritance in java with an example" will be real implementation from core java ... |
I am sure this type of question is asked every day, but I am struggling with understanding why the mammal object is instantiated as a cat, and reports its name to ... |
I have a software setup with 2 layers, a core layer and a customer specific layer. The core layer has defined constants which the customer specific layer should be able to ... |
Can anyone tell me how the implicit inheritance works in java internally?
What I mean is if I create a class how exactly it extends the Object class in the JVM?
Thanks in ... |
I have the following code:
public class GrandParent {
public void greet() {
System.out.println("Hello from grandpa.");
...
|
Here i've got some code to "transfer" an inner core model to an "output" model for external plugins.
For doing this, I create new instances based on the concrete subtype of ... |
What do we mean when we say "All classes either directly or indirectly inherit from class Object"? What constitutes a class indirectly inheriting the methods declared in its indirect superclass?
Can ... |
@zoellus Class Payment is another class than class Select; each object has its own 'name' and 'price', both inherited from their common super class Vm. Here's an example: both you and ... |
Sir, i'm doing a Phd work on quality metrics . So basically i'm developing a tool for just checking out the number of classes,elements,inheritances & level of inheritance in a given ... |
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P: 4 Casey Daniels Hello All, Still new to Java but got pass the messing around phase and am actually starting on a Project. What I'm trying to do is build ... |
Banning concrete inheritance (Java in General forum at JavaRanch) A friendly place for programming greenhorns! Register / Login Java Forums Java Java in General Banning concrete inheritance Post by: Ernest Friedman-Hill, Marshal on Aug 31, 2005 20:00:00 In another thread we were starting to talk a little about the design of an ideal language. One of the problem features ... |
I was looking at the Properties class in Java and the comment said that as Properties inherits from Hashtable one could call put and putAll on a Properties object and that this was a problem because Properties should only contain Strings. This got me thinking. First I thought - what a lame idea inheriting from a class when not all the ... |
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Hi there. My question is as follows: I have two classes: StringLayer(located in a package called "gui") and OpenMapLayer(located in a package called "mypackage1") where OpenMapLayer extends StringLayer. Layer is a third class that is the parent of StringLayer(not really relevant here - I think!). When I add layers to an array of objects I declare them as either StringLayer objects ... |
A friendly place for programming greenhorns! Register / Login Java Forums Java Java in General Hierachies and inheritance Post by: bitzack zack, Greenhorn on Nov 23, 2004 16:38:00 Hi all, I am trying to make some small changes to the version of this code: I want to implement the changes listed below and run it as an application not ... |
It is declared in the API that the class Graphics2D extends from Graphics class. In an example given in the tutorials on java.sun.com, i came accross a code that is as follows: public void paint(Graphics g) { ... Graphics2D g2 = (Graphics2D) g; ... } How is this possible? i belive that casting to a Sub class from a Base clase ... |
hi 1>private methods are not inherited, but can have similar looking method in subclass....please give me a example 2> i guess final and static methods are inherited and can be overloaded .....both final and satic methods can not be overridden ,but static method can be redefined in subclass...does redefined means overloaded.....please give a example |
I'm working on a program using inheritance, and I'm runnning into one problem. In my "Stuff" class, my pop method needs to decrement by one each time subtracting the last word and returning it to be printed. The array from the test will be "code test is this". The result I want from pop is for it to print in seperate ... |
I'm trying to write a model of a manufacturing factory. There are feedstocks, composants and finished products. So far I've got roughly this: public interface PartInterface { public PartType getType(); } public interface FeedStockInterface extends PartInterface { //code not important here } public interface ComponentInterface extends PartInterface { //code not important here } public abstract class Part implements PartInterface { enum ... |
hi friends, if I am trying to implement in one class two interfaces that has methods with the same signature, how do i escape from the ambiguity problem. is there a way to notify in the syntax who is the father of the interface i am trying to implement (like in c++). could you please give me some syntax/code example. thanks, ... |
Hey Dudes, I have an interesting point to be discussed in Inheritance. In Inheritance we reuse the parent's members in the child class rather than redefining the whole thing. Now, let us say we have a parent class with three members A,B and C. And if requirement is like - I need to define 2 classes, out of which one should ... |