When we say derived class that means copy of base class plus subclass specific implementations. But when it comes to private members it cannot be accessible in subclass scope. Does it mean byte code generated for subclass doesn't has byte code of private members of super class ?
View RepliesI have this piece of code I wrote a while ago to test something. The issue is accessing a private field of Base class in Base but of a Derived object.
Here is the code:
class Base
{
private int x;
public int getX()
[Code]....
The commented code does not work but casting d to Base does.
Forgot to mention that the compilation error is that x has private access in Base.
If i have a class(lets say class name is Approval) with the following private members: String recip_id, Int accStat, String pDesc, String startDate How can i create public get and setter methods for these private members of the class?
View Replies View RelatedWe have a large applet based application with a current client-side minimum jar download size of ~4MB. If we put ALL of our class files into jars, that size will probably double. Most users only use a small portion of the class files for their particular tasks. Having ALL users download ALL the classes, compressed in jars, is extremely time consuming and a major problem after application updates due to the large number of users and the network load it would cause.
So after downloading some basic jars other needed individual class files are downloaded as and when requested by user. For signing applet, applet class files are moved to jar and this jar is signed with following attributes in manifest.
Jar file manifest:
Permissions: all-permissions
Codebase: *
Application-Name: XYZ
Application-Library-Allowable-Codebase: *
Trusted-Library: true
When applet is invoked from browser with JRE 1.7.51, there is a security blocked exception for individual files which are accessed from the signed applet jar. Why individual class files are blocked? Is it necessary to move all individual class files in a jar?
1. I want to use a scanner in my child class so that I may populate my parent class. It won't allow me something about scanner constructor. I posted this issue second which is my child's method Tests
2. I can't call my addTestsAnswers method from main to my child class but can call my child's display method from main.
import java.util.Scanner;
public class Tests extends Assessment{
private String q;
private String a;
private int userInput;
Scanner scan = new Scanner();
Scanner scn = new Scanner();
Scanner u = new Scanner();
public void addTestsAnswers(){
[code]....
When importing static members of a class. Why are they only accessible within the constructor of the calling class, and not outside of it? Here's the source code to understand my question.
package Certification;
public class ExamQuestion {
static public int marks ;
static public void print(){
System.out.println(100);
[Code] ....
I have two classes in two different files.
Color.java and Light.java
The Color class:
public class Color {
private int red;
private int green;
private int blue;
public Color(){
red = 0;
green = 0;
blue = 0;
}
And i have the Light class :
public class Light {
private Color color1;
private boolean switchedon;
public Light(int red, int green, int blue){
//dont know what to write here . how can i use the members of the Color class here ? without using extends.
}
}
I am trying to implement the following example to override the equality and hashCode method if the class has reference type member. I do get the expected result "true" for equal and "false" for non-equal objects. But the print statement in the Circle's equal method is not executed when the objects values are not equal. I don't know what i am missing, though i get the equality result "false" as expected for non equal objects.
class Point{
private int x, y;
Point (int x, int y) {
this.x =x;
this.y = y;
[code]....
can we pass private final class object to another class constructor?
View Replies View RelatedI'm working on a project that contains multiple classes. Each class contains and must contain only PRIVATE variables. Here's my issue. When my test code calls for a new instance of "StudentClass" as so:
StudentClass studentClass = new StudentClass(offeredClass.getClassIdNumber(),
offeredClass.getClassName(),
offeredClass.getClassroom());
The corresponding constructor won't let me initialize it's variables because they are declared private within another class, as shown here:
StudentClass (float classIdNumber, String className, Classroom room){
this.classIdNumber = classIdNumber;
this.className = className;
this.room = room;
}
When getClassName, getClassroom, and getClassIdNumber are passed to a toString() method elsewhere in my test code. the output is returned just fine. When passed through the StudentClass, I'm getting Null across the board.
Java Code:
import java.util.Scanner;
import java.util.ArrayList;
public class Problem1
{
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
ArrayList<String> list = new ArrayList<String>();
[Code] ....
There is an error and says that my ArrayList has private access. I can't figure out how to fix it.
The code runs but when I enter "Quit", the program just stops. The arraylist isn't printed out?
When creating a class with a constructor, why does one have to create private variables (attributes) to be used as parameters by the object? The object's parameters will be set to be exactly equal to the private variables (attributes), so what is the point of having the private variables (attributes) Why are both private variables (attributes) and parameters needed when they are set to be equal each other anyway?
View Replies View RelatedI came across the below
1) When a variables are declared "Private" How should it be accessed from the driver class ? Sometimes i get an error in driver class saying "your variable is declared Private" why am I getting this error ...
The document says "Private" declared variables should be accessed only through methods. What does that mean.
I have a class named Base and a private variable named _hopcount i have 10 instances of class base i use _hopcount as creteria to some if but other instances edit _hopcount so i want to prevent _hopcount edit by other instances; I want to have private variable which other instances of same class can't modify it.
public class Base extends TypedAtomicActor {
private int _hopcount = 0;
if(_hopcount <= 3) {
some code;
}
public function() {
_hopCount += 1;
}
}
I got a task from my teacher and the restriction is we are not able to modify this class (and that is the problem).This is the given class:
public class Jobs {
private intcounter= 0;
private final intnoElements= 20;
private final int[]a= { 11, 28, 31, 42, 49, 66, 67, 75, 89, 100, 102, 103, 114, 125, 130, 135, 140, 145, 150, 155 };
private final int[]s= { 20, 9, 7, 6, 12, 15, 4, 7, 30, 22, 11, 45, 20, 6, 6, 5, 5, 5, 5, 5 };
[code]...
I need to compare some of the values of the given arrays. For example: if(a[4]<a[2])... etc.
How can I do these kind of operations to a private array? I have to compare the values in an new classPS: I have to compare the values in a new class
I've got an abstract class
public abstract class AbstractClass
{
//stuff
}
And a few classes that inherit from it
public class Class1 extends AbstractClass
{
//stuff
}
public class Class2 extends AbstractClass
{
//stuff
}
within another class I have a private variable with the type of the Abstract class, and within one of the methods I assign an object to the the variable like this:
public class Test
{
private AbstractClass temp;
public testMethod(){
Class1 anObject = new Class1();
temp = anObject;
}
}
Is this legal? Will temp become a Class1 object?
The String class stores the characters of the string internally as a private char[] and calling someString.length() results in getting the length field from the character array. I am looking to get the details on how the length is implemented. I understand it is a field, but in the original question I provide sample code and really want to know if/how the resulting byte code may differ when compiled, perhaps I am just not seeing the simple answer through my confusion.
Link ....
I am wondering if there is a way in jave to use enums WITHIN a class (without creating a separate enum class) without using private static final. Something like as folows:
class My Class {
myEnum {ACTIVE, INACTIVE, PENDING};
}
is there something like this available?
Okay, I am supposed to implement the functionalities of the Set class using a private data member of type ListReferencedBased<E>,how the ListReferenceBased works with what I am trying to accomplish.I am trying to complete Set.java, and I have barely started and much of the code doesn't work. ListReferenceBased was given to me completed.
import java.util.Iterator;
pubic class ListReferenceBased<E> implements ListInterface<E>, Iterable<E>{
/** reference to the first element of the list */
private Node<E> head;
/** number of items in list */
private int numItems;
[code]....
Adding Node derived objects to SceneBuilder is easy and works fine.
I'm wondering how to add non-Node derived objects. It seems to be possible as MenuItem derived objects are listed and can be used.
How to add custom types (not Node derived) to SceneBuilder?
I am trying to call a private method to another method that are located in the same class.
I am trying to call prepareString to the encode method below.
Java Code:
public class ShiftEncoderDecoder
private String prepareString(String plainText)
{
String preparedString = "";
for(int i = 0 ; i < plainText.length();i++)
if(Character.isAlphabetic(plainText.charAt(i)))
[Code] .....
Why static member are allowed to be accessed with class-name and a null reference?
Here's the given code.
class Employee{
public static Integer companyId = 1001; // this could be private.
public static Integer getCompanyId(){
return Employee.companyId;
}
//a setter method will be here if the companyId will be private.
}
public class TestStatic{
public static void main(String[] args){
Employee emp =null;
emp.companyId = 11111;
System.out.println(emp.getCompanyId());
}
}
In this code the static members of a class are accessible by the null reference of that class.
These can also be access by the class (Employee.companyId or Employee.getCompanyId()).
What is the difference here in both. why a null reference can access these static members.
can we achieve runtime polymorphism by data members?
View Replies View RelatedI was trying to come up with the design for a library. Here are the requirements:
The library maintains a record of books and its members. It allows members to check out books. Books can be searched by author name or title. The books are classified into 4 categories - General, Sports, Politics, Business.
I've come up with this initial design:
Classes:
Category (enum)BookMemberLibrary
Category
Attributes: SPORTS, GENERAL, POLITICS, BUSINESS
Book
Attributes: String title, String authorName, Category category, boolean checkedOut
[Code] .....
I have a problem with this ascii animation program I am working on. I declared a method inside of my class AsciiAnimation extends JFrame implements ActionListener, called
package AsciiAnimation;
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;
import javax.swing.*;
public class AsciiAnimation extends JFrame implements ActionListener{
int currentFrame = 0;
ArrayList<String> frameList = new ArrayList<String>();
[Code] ....
Basically I just am trying to figure out how java works with me accessing those 2 data members, currentFrame and frameList inside of my first class ALL in the same package.
I am to design a program in java that will allow a user to Input a list of your family members along with their age and state where they reside. Determine and print the average age of your family and print the names of anyone who live in Texas. I have tried but my results are wrong.
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