Program Shows Error While Using Super Keyword
Jan 3, 2015//constructor
class Base
{
Base(int a) {
System.out.println("in base"+a);;
}
}
class Cons extends Base
[Code] .....
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JSP :: Eclipse Project Window Shows Error But Code Editor Shows No Error
May 22, 2014For my jsp file, the code editor shows no error, but the projects window shows an error. I built my project again, cleaned the project, restart eclipse twice and summoned cthulhu. But my project still shows an error. How do I find the cause.
Eclipse project -
JSP file -
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<%@ taglib prefix="mine" uri="DiceFunctions"%>
[Code] ....
Generics Super Keyword
Feb 14, 2014Suppose I have
class A {
public void speak() {
System.out.println("I am class A");
}
}
class B extends A{
public void speak() {
System.out.println("I am class B");
}
}
class C extends B{
public void speak() {
System.out.println("I am class C");
}
}
Why this doesn't work while A is a super type of B ?
public static void insertElements(List<? super B> list){
list.add(new A()); //not OK, why?
}
Super Keyword When Used Explicitly In A Subclass Constructor
Jul 9, 2014The 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 ?
View Replies View RelatedSuper Class - Getting Error Identifier Expected
Aug 9, 2014I created a superclass Ships and under that a class CivilShips. Under that HumanBulkFreighter.
I declared variables in Ships and CivilShips and wanted to have them set in HBF to a specific value. When I know try to compile them I get the following:
HumanBulkFreighter.java:2: error: <identifier> expected
cargo=1500;
^
HumanBulkFreighter.java:3: error: <identifier> expected
size=200;
[Code] ....
Trying To Create Custom Resource Bundle Shows Error
Jan 15, 2014I am using jdev12c. I tried to create the following class
package view;
import java.awt.Dimension;
import java.util.ListResourceBundle;
public class Resource extends ListResourceBundle {
protected Object[][] getContents() {
return new Object[][] = {
[Code] ....
The code is copied from java documentation ListResourceBundle (Java Platform SE 7 )
Looks like a documentation bug where "=" has to be removed
Difference Between Static Keyword And Transient Keyword
Oct 7, 2014What is the difference between the static keyword and transient keyword?
View Replies View RelatedProgram Shows No Output In Eclipse In NetBeans
Oct 1, 2014It has no errors in it, but when it runs, it just doesn't show any output at all. Here's my code.
Fuel Class:
public class FuelGauge {
// Setting the gallons and the total amount of gallons
private int gallons;
final static int TotalGallons=15;
public FuelGauge(){
gallons=0;
}
// Initiate the number of gallons
public FuelGauge(int gallons){
[Code] .....
Create A Program That Shows Three Test Grades And Average
Jan 28, 2015package Program1;
import java.util.Scanner;
public class Source1 {
[Code].....
using netbeans to debug the program but i'm not sure what I did wrong as it doesnt go past test 1
Program That Shows A Square Frame Filled With 100 Buttons Label
Apr 13, 2014Write a program that shows a square frame filled with 100 buttons labeled 1 to 100. Nothing needs to happen when you press any of the buttons. I keep getting errors i am a beginner.
import java.awt.Frame;
import javax.swing.JButton;
import javax.swing.JPanel;
class TestFrame extends Frame {
[Code] ...
When Remove Increment Operator Program Shows Invalid Statement
Feb 19, 2015class Brain56
{
public static int[] get()
{
return null;
}
public static void main(String...a)
{
int k=1;
get()[k]++;
}
}
when i remove the increment operator(get()[k]) program shows invalid statement may i know the reason behind it?
Nothing Shows Up In Output File?
Apr 21, 2015I am working on a program that accept input file from user and then from the input file, it count the occurrence for each words then put those result into the output. However, after I run this program, nothing shows up in the output file. It is totally empty...It seems nothing wrong with my code... Here is my code
import java.util.*;
import java.io.*;
public class occurance {
public static void main(String[] args){
String inputFileName="";
String outputFileName="";
if(args.length == 0){
[code]....
Map That Shows The Stock Of Some Company
Dec 16, 2014Is there anyway i could clean this up. ??
package map;
import java.io.*;
import java.util.*;
public class Map {
public static void main(String[]args)throws Exception{
[Code] .....
Nothing Except Frame And Label Shows Up
Apr 3, 2014Java Code:
import java.awt.*;
import java.awt.event.*;
public class TestFrame extends Frame implements ActionListener {
static int i;
Frame fr;
Button b1,b2;
Image img[]=new Image[3];
[Code] .....
Java Generics Super And Ext
Jun 17, 2014Set<? super TreeMap> s = new HashSet<SortedMap>();
SortedMap<String,String> sm = new TreeMap<String,String>();
TreeMap<String,String> tm = new TreeMap<String,String>();
s.add(sm); //This fails
s.add(tm);
Why does adding sorted map to a Set that allows ? super TreeMap and instantiated as such fail?
Not Getting Output From Array But Debug Shows Data Is There
Jul 1, 2014I am working on a simple JAVA tutorial, not homework, where employee data is taken from an array and displayed on the console. The data is divided by department, age, name and for the Accounting and Information Systems departments, they are displayed in ascending order by employee age. Everything works except I am not getting the output to the console other than the titles. As I step through the debug, the data clearly is populating the array.
Here is my code:
Company Class:
package SimpleJavaAssignment;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.*;
[Code] .....
Prime Age Checker:
package SimpleJavaAssignment;
import java.math.*;
public class PrimeAgeChecker {
public boolean PrimeAgeChecker(int age) {
BigInteger bi = new BigInteger(String.valueOf(age));
boolean prime = bi.isProbablePrime(10);
return prime;
}
}
Swing/AWT/SWT :: JFrame Only Shows Three Borders And No Contents
Dec 3, 2014My code is running via javaw on Windows 7 and XP. It sits in the background waiting for a barcode to be swiped, and then wakes up and asks a question. The trouble is that sometimes (definitely not always), it shows like this:
The code is:
public static void Question(String sTitle,String sLabel) {
JFrame window = new JFrame();
// Create a modal dialog
d = new JDialog(window, sTitle, true);
d.setLayout( new BoxLayout(d.getContentPane(),BoxLayout.Y_AXIS) );
JPanel p1 = new JPanel();
[Code]...
Initially I though it might because I had another thread running which occasionally put up announcement messages in JFrames. But I have taken this out and the problem still persists.
Laptop Screen Shows White Lines
Apr 28, 2014When I open applications specially high graphics applications, the screen flashes with whole black display with a number of horizontal white lines then after 2 or 3 flashes it opens the desired program. What is the cause, is it low graphics memory, physically damaged screen or ?
View Replies View RelatedSwing/AWT/SWT :: Relationship Between Super And Child?
Aug 27, 2014I want to make an application and must use strategy pattern my idea is to create a super class in this case Movie Player and three sub classer and they'll komminesera with each other using strattegy pattern, one of the sub classes is Button Panel and I want to add it to Movie Player and it was to be its child,so how can I add the butt panel to Movie Player and it shall be its children?
MoviePlayer:
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import com.github.sarxos.webcam.WebcamPanel;
[code]....
Super Call / Subclasses And Inheritance
Feb 12, 2014what 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;
}
Why Use Extends Keyword Instead Of Implements In Generics
Feb 22, 2015Why java uses the keyword extends when setting the bound of a type parameter(Generic) to an interface. I think using the keyword implements is more intuitive.
public static <T extends Comparable<T>>
why use extends? and not implements.
int countGreaterThan(T[] anArray, T elem) {
int count = 0;
for (T e : anArray)
if (e.compareTo(elem) > 0)
++count;
return count;
}
I know if I want to set multiple bounds I will use extends keyword, and I will concatenate the bounds using & operator.
Is this a design decision to always use extends keyword to set bounds?
Static Keyword For Arraylist Containing Objects
Jun 14, 2014I've come across something that i'm not overall sure about regarding the static keyword in Java.I'm making a vertical scrolling game where the player simply shoots enemies and they shoot back as they fall, dropping items if they die such as power ups and coins. I have an enemy called Bat and this is the bullet creation code in the update method:
if(oldPlayerY + 220 > posY && getBulletDelay > 0.90f){
batBullets.add(new Bullet(posX + 10, posY - 10));
getBulletDelay = 0;
}
The method is creating a new bullet object and it then adds that to the arraylist called batBullets, which is simple enough. I then need to access this arraylist in the main game update class so I can render those bullets on the screen, even if the bat dies. I was always taught that you use the static keyword when you need to access something from the class that doesn't require an object. Because of this, I have the following code.
for(Bullet bullet : Bat.batBullets){
bullet.setY(bullet.getY - 5); // Set the bullet to fall
renderMap.getSpriteBatch().draw(bullet.batBullet(), bullet.getX(), bullet.getY()); // render the bullets
}
This seems perfectly fine to me because I need to access the batBullet arraylist and it doesn't make sense to create a new bat object as I already have random spawning in place for them.
How Registry Can Look Before Java Install - Keyword
Dec 2, 2014I am attaching a document which shows the current state of my registry.What I want to know is if I can [safely] delete the JavaSoft folder with all lower subfolders, then re-install jdk1.6/0_31 which, I am told, is the current version being used here by developers.According to others on the development team (not my team), there COULD be something in the registry that is preventing both the installation of java jdk AND its uninstallation.Since I cannot seem to attach any kind of document.
View Replies View RelatedSuper Constructor Call - Creating Object
Sep 18, 2014Its written that every constructor calls its super class constructor. And we know, constructors are called to create an object. Does it mean that if I am creating an object of a class, I am actually creating objects of all its super class???
View Replies View RelatedHow To Get Access From Variables In Super Class Or Subclass
Dec 2, 2014how 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;
in my class i have 6 argument constructor
Set Methods In Super And Subclass By Using Dialog Boxes
Nov 7, 2014I 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.
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