Overriding - Use Public Access Modifiers With String
Apr 2, 2015Why do we use public access modifiers with String toString() method in java while overriding???
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Access Modifiers For Variables
Aug 15, 2014Does a variable have public access modifier? if we can use it within the class and outside of the class then can i access a public variable as follows??
class mo
{
void display() {
public int a=9;
System.out.println(a);
}
public static void main(String[] args) {
mo m=new mo();
m.display();
}
}
ERROR:
It shows 6 errors :-O.
Error 1. illegal start of the expression
2. class,interface, or enum expected
Abstract Classes And Access Modifiers
Jan 21, 2015I'm having difficulty understanding this small piece of code:
package food;
public abstract class Fruit {
private String color;
private String tasteType;
public void setColor(String color) {
this.color = color;
}
public abstract void setTasteType(String taste);
}
The above is an abstract class which describes the basic structure that every fruit should "extend".
The below is a concrete subclass of the Fruit class called Apple.
import food.Fruit;
class Apple extends Fruit {
public void setTasteType(String taste) {
tasteType = taste;
}
}
Also do note that the two pieces of code are in different packages!
Upon compiling the Apple class I get the following error:
Apple.java:4: error: tasteType has private access in Fruit
tasteType = taste;
^
What I don't understand is this: I've given a non-abstract implementation to the "setTasteType" method in the Apple class and clearly setTasteType should have the authority to modify the private instance variables of Fruit. But it turns out I'm wrong.
Java Source Code File Naming With Access Modifiers
Feb 3, 2014Why is this not valid in java:
Both uses public with the same class/interface name.
Test.java:
public class Test implements Test{
/// Some codes
}
public interface Test {
///Some methods
}
Why Cannot Access A Public Method From Another Class
Feb 12, 2015Why can't I access a method from another class? For example, I want to get the value of get method from another class. It's giving me an error on if(getExamType() == 'M') That's what I've done, for example:
Java Code:
public static Exam[] collateExams(Exam[] exams){
Exam [] r = new Exam[50];
r = exams;
Exam [] finalExam = new Exam[50];
for(int i = 0; i < r.length; i++) {
if(getExamType() == 'M') {
}
}
return r; mh_sh_highlight_all('java');
Unable To Access A Method Which Is Public From Servlet
May 13, 2014I am trying to assess a method which is public from servlet. but it gives weird error. image has been attached .....
View Replies View RelatedJava EE SDK :: CDI Bean Cannot Access Public Method Of Unmodifiable Collection
Jan 10, 2010I've got a CDI bean which is a facade for a JPA entity. Such entity has got a many to one relationship with itself and I've got the following method:
public Set<Account> getChildren() {
return this.children;
}
which is called in a JSF/Facelets page:
<h:commandLink action="#{accountController.destroy}" value="#{bundle.ListAccountDestroyLink}" rendered="#{item.children.size() == 0}"/>I then decided to return an unmodifiable set and changed getChildren() accordingly:
public Set<Account> getChildren() {
return Collections.unmodifiableSet(children);
}
The page now reports this error:
java.lang.IllegalAccessException: Class javax.el.BeanELResolver can not access a member of class java.util.Collections$UnmodifiableCollection with modifiers "public"
at sun.reflect.Reflection.ensureMemberAccess(Reflection.java:65)
at java.lang.reflect.Method.invoke(Method.java:588)
[Code] ....
javax.el.BeanELResolver is incorrectly failing because it's trying to invoke the size() method using reflection without correctly taking into account the method visibility (which is indeed invokable programmatically). I'm running NetBeans 6.8, Glassfish 3.0 and jdk1.6.0_17.
Is this a bug in BeanELResolver?
How To Compare Public String Value
Sep 7, 2014I want to make a program in which i write the Months Strings via while into the checkbox.
I already did that but i have also to add an day if February is a loop day.
So my question is how to say java that if Months is equal to February & year is a leap year, add 1. (i didn't wrote the year code because it's not relevant for my problem.)
Java Code:
public String[] Months ={"January","February","March","April","May", "June", "July", "August", "September", "Oktober", "November", "December"};
public Asg1KeapYear() {
initComponents();
int MonthNo = 0;
[Code] ....
Netbeans shows me .equals() on incompatible types on Months.equals, do i have to declare it somehow?
Why Are Final And Abstract Called As Modifiers
Feb 8, 2015I just wanted to know that why are final and abstract called as modifiers ,what is the essence of calling them as modifiers since there are two types of modifiers access modifiers and non-access modifiers so final and abstract come under the second category ,so why are these called as modifiers?
View Replies View RelatedHow To Access String Arrays From Console List
Apr 8, 2014We were suppose to make a program for an assignment and the prof provided some codes to start of. What does this basically mean? How do i access the string arrays from consolelist?
class ConsoleInfo {
private String conTitle;
private double conPrice;
private int conQty;
private String conPic;
private static String empPassword;
ConsoleInfo(String title, double price, int qty,String pic)
[Code]...
How To Access 4 Strings Randomly From String Array
Jun 13, 2014Now I am trying to print the 4 string randomly from string array..where string contains no of words which are splitted from the file....
View Replies View RelatedOverriding Inherited Methods
Feb 5, 2015So the first thing I would like to ask about is overriding inherited methods. I am asked to override methods in one of my assignments and I am not really sure how to go about doing it.
View Replies View RelatedOverriding Static Method
Aug 30, 2011class One
{
public static void doStuff()
{
System.out.println("One");
}
}
class Two extends One
[code]....
My understanding of static says that static methods cannot be overrriden but the compilation of the above code results in Overriding rule violation error.
Warning For Not Overriding Methods
Mar 26, 2014import javax.swing.*;
import java.awt.*;
import javax.swing.event.*;
import java.awt.event.*;
/* display selected number
if selected, bg is green
if not selected bg is pink
*/
[code]....
my compiler is telling me that the getList... method is not being overridden.but when I change the JList<String> to JList and Object to String in the parameters, i get a warning from the compiler that it's an "unchecked call".
Overriding CompareTo From Comparable Interface
Oct 31, 2014Here is my code:
/*
* Implement the Comparable interface on objects of type Order.
* Compare orderId, then productId. The lesser orderId should come first. If the orderIds match, then the lesser productId should come first.
*/
@Override
public int compareTo(Order ord) {
// TODO Auto-generated method stub
if(orderId > ord.orderId){
return 1;
[Code] ....
Here is the output:
Actual: 0
Expected: -1
Actual: -1
Expected: -1
Actual: 1
Expected: 1
Actual: 1
Expected: 1
Actual: 0
Expected: 0
Actual: 0
Expected: 0
In short, the "Actual" is what my code produces and the "Expected" is what it is supposed to produce. As you can see, only the first one is mismatching... I'll admit, the comment section above the method is confusing and I wasn't exactly sure what it wants me to do, but I thought I figured it out. I just don't see how 5/6 of these tests can work and the 6th one not.
Return Statement In Method Overriding
Jan 1, 2015class Base
{
public Base rtc() {
System.out.println("am in parent");
return new Base();
}
}
class Ret extends Base
[Code] ....
Output :
I am in child class but b1.rtc requires b2 to hold the return value y not Ret's object.
Clarity On Overriding Equals Method
Oct 2, 2014For a few days I've been reading about the importance of overriding the equals method. How overriding it actually determines or checks the values stored in the variable. I realize that you can check the values stored in the primitive datatypes with "==", and when you don't override the equals method it acts the same way, right? When used with a reference datatype, "==" or the default equals() method only compares, or sees, if the variable is pointing to the same instance of a class. For some reason, in the examples, what is taking place to actually check the values stored inside the variables.
Here is part of an example (I've added comments for things that are confusing me):
@Override
public boolean equals(Object obj) {
//So we use Object here instead of the class type
// we're overriding this equals method for?
Is this so that we can use it to check different types? (overloading?)
if (obj == this) {
return true;
//Isn't this checking to see if the calling object is the same as the object we're passing to it?
Why doesn't this return false?
}
if (obj == null || obj.getClass() != this.getClass()) {
return false;
}
//How exactly do we check the values stored in each object though?
}
Overriding ToString - Indicate Whether Coin Is Face Up Or Down
Jan 2, 2015what im trying to do is modify the Coin class to override the toString() method so that it indicates whether the coin is face up or face down. For example, "The coin is face up." This is what i have so far:
public class Coin {
public static void main(String[] args) {
Coin coin = new Coin();
for (int i = 0; i < 1; i++) {
coin.flip();
System.out.println(coin);
[Code] .....
Overriding Equals Method From Object Class
May 5, 2014I am attempting to override the equals method from the Object class which checks if two variables point towards the same object. I want the method to check if if the argument being passed in(an object) has the same data(instance variables) as the object that's calling this method. A NullPointerException is being thrown; Here is the code.
package javaapplication5;
import java.text.NumberFormat;
import java.util.Scanner;
import java.lang.Object;
public class Product {
private String product;
private String description;
private double price;
[Code] ....
And here is the stack trace
Exception in thread "main" java.lang.NullPointerException
at javaapplication5.Product.equals(Product.java:42)
at javaapplication5.Product.main(Product.java:24)
Java Result: 1
Overriding Java ToString Method For Web Browser
Mar 14, 2014How do i print override the toString for WebBrowser as i would like to print out the object bc. Tested the program and it is fine if i put it in the main method rather than the WebBrowser constructor.
import java.util.*;
class ListNode <E> { /* data attributes */
private E element;
private ListNode <E> next;
/* constructors */
public ListNode(E item)
{ this(item, null);
[code]...
Overriding In Java - Foo Method Of Class X Is Not Throwing Compile Error
Jul 29, 2013class SubB{
public void foo(){
System.out.println(" x");
}
}
public class X extends SubB {
public void foo() throws RuntimeException{
super.foo();
if(true) throw new RuntimeException();
System.out.println(" B");
}
public static void main(String [] args){
new X().foo();
}
}
Why the foo method of class X is not throwing a compile error because according to the override rule, if the superclass method has not declared exception, the subclass method can't declare a new exception...
One Public Class Per File
Feb 8, 2014The compiler won't let me declare more than one class as "public". Am i correct in understanding that this is a java restriction ? This means i need to create a new file, for each public class that i want in a package ? The rest of the classes without access modifier will all be package-private. (Q has been asked before probably, but my search could not be narrowed).
View Replies View RelatedHow To Use Public Double GetXCoordinate
Dec 9, 2014I am trying to understand a question:
R2 (x,y) -- Make the Point class code that implements a corresponding abstraction to a given point in R2. You should explicitly provide the manufacturer's code P (double x, double y) for the Point class. And code for the methods, whose definitions are:
- public double getXCoordinate ();
- public double getYCoordinate ();
- public setXYCoordinates (double x, double y);
- public moveTo (double x, double y);
- public printAtts ();
Calling Public Function In JInternalFrame
Aug 31, 2014Is it possible to create a JInternalFrame class with additional public functions that can be called from the desktop? Here is some snippets of the code. This is the Internal Frame with the public functions added after the constructor.
public class Search_Ifr extends javax.swing.JInternalFrame {
/**
* Creates new form Search_Ifr
*/
public Search_Ifr() {
initComponents();
[code].....
The line " ifrSearch.setTabPaneIndex("tabCust");" is throwing a compile error that the method is not found.
Public Type (name) Must Be Defined In Its Own File
Apr 1, 2014I have a small issue understanding the following error message that Eclipse returns when i try to run the following code:
class Film {
String tytul;
String rodzaj;
int ocena;
void odtworz() {
System.out.println("Odtwarzamy film.");
[Code] .....
The message itself reads: "Exception in thread "main" java.lang.Error: Unresolved compilation problem:
at FilmTester.main(Film.java:13)"
and the following on the line where the problem arises:
What gives? I'm positive i'm missing something obvious but i can figure it out why
Make Http Server Creation Public
Mar 3, 2015Now, I would like to properly stop the server. For that, I can do server.stop(); . However, this does not work since the object server is not public, it is contained within the public pc_proxy class.How do I do that?
Java Code: import java.net.*;
import java.io.*;
import com.sun.net.httpserver.*;
import java.util.concurrent.Executors;
import java.lang.reflect.Array;
[code]....