Sort 2 Different Objects In Self Made Generic Class Using Comparator
May 31, 2014
Ok here are my 2 Classes
Both have Identical Fields
package com.Lists;
public class EmployeeOffice implements EmpInterface {
private double salary;
private String name;
private String postion;
private double hoursWorked;
[Code] .....
So if i wanna sort this Generic class using comaparator what do i do... I cant find an answer to this... I wanna sort them on the basis of salary what to do ...
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Apr 14, 2015
I am working on my generic insertion sort program. When I completed and run my code, I am having trouble with my code. So, I am just trying to see if I get an correct array from a file. However, i just get so many nulls in the array. Therefore, I can't run my insertionSort function because of null values.
Here is my code
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
[Code].....
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Jul 23, 2014
1 import java.util.ArrayList;
2 import java.util.List;
3
4 public class MyList<E> {
5
6 public List<E> list;
7 public int length;
[code]...
I am trying to define a class MyList, which i just a wrapper around an ArrayList, no real purpose, just for the sake of learning Generics. Idea here is that I create a parameterized class, MyList<E>, which holds a parameterized instance var of type List<E>. I have an add method which adds an element of type E to the List<E>. If I create an instance of MyList, call it 'm', for some reason when I try to call a method on that instance the compiler complains that 'm' cannot be found.
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Jul 4, 2014
Is it possible to compare 100 objects using comparator interface in java?
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Oct 7, 2014
I've implemented Stack on the base of the LinkedList. It works as i expect it to work, but then i tried to made it compatible with foreach loop. I've implemented Iterable and Iterator. Code compiles and works fine, but does not return any output. It looks like while working with foreach, next() is not called at all. If i`m getting iterator from instance and try to do iterator.next(), i get output as expected.
public class genericStack<T> implements Iterator<T>, Iterable<T> {
private LinkedList<T> LL ;
protected genericStack() {
this.LL = new LinkedList<T>();
}
public static void main(String[] args) {
[Code] ....
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Jul 15, 2014
I am following this article : [URL] ....
It is important to note that the inference algorithm uses only invocation arguments, target types, and possibly an obvious expected return type to infer types. The inference algorithm does not use results from later in the program.
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May 16, 2008
I have set up a project in Eclipse 3.1 and am using java 5.0 compiler.
Here's my folder structure in Eclipse
Java Code:
DFSRemoteClientTestClient.java mh_sh_highlight_all('java');
DFS is the project in Eclipse
And this is how it looks my java class
Java Code:
package RemoteClient;
import java.util.*;
// other imports
public class TestClient {
public static void main(String [] args) throws ServiceInvocationException {
// business logic here ....
}
} mh_sh_highlight_all('java');
So, basically, my java class is just a simple class with a main function.
Now when I build my project, using Project->Clean...
Then I get this as an error at the very first line where i specify the package
This is the error:
Java Code: The type Class is not generic; it cannot be parameterized with arguments <T> mh_sh_highlight_all('java');
What's this error and why am I getting this.
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Mar 5, 2015
How do you declare methods for a class within the class whilst objects of the class are declared else where?
Say for instance, I have a main class Wall, and another class called Clock, and because they are both GUI based, I want to put a Clock on the Wall, so I have declared an instance object of Clock in the Wall class (Wall extends JFrame, and Clock extends JPanel).
I now want to have methods such as setClock, resetClock in the Clock class, but im having trouble in being able to refer to the Clock object thats been declared in the Wall class.
Is this possible? Or am I trying to do something thats not possible? Or maybe I've missed something really obvious?
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Mar 22, 2015
I have a String repersentaion of some Object.I want that object convert back into some class type how can I do this?
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Jun 5, 2014
How the recursion works. I tried to figure out writing down low, mid, high at each recursive call. But I seem to be making a mistake somehow. I don't understand where the values are returned to in
if(leftmax>rightmax){
return leftmax;}
else
return rightmax;
Here's the code:
public class Maximum{
public static int max(int[] a,int low,int high){
int mid,leftmax,rightmax;
if(low==high)
return a[low];
[Code] ....
firstly leftmax=max(a,0,4)
Then what is the next line executed?Is it rightmax=max(a,5,8).
After this is it leftmax=max(a,5,6)
rightmax=max(a,7,8)
I tried to understand what these recursion calls by writing them down.But I somehow make a mistake.
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Apr 16, 2015
I am trying to make a for loop using an iterator that refers to an object of a class that hasnt been made yet. The class is called MyArrayList but it does not have a Main. A MyArrayList object is made externally so I am unsure how to refer it to the object from within the class. Is there a place holder I could use such as Object.Iterator() or something similar. I have created an inner class that implements the Iterator interface. Here is the code that I need to adjust to do this:
public class ListIterator<E> implements Iterator<E> {
public myIterator() {
Iterator it = MyArrayList.iterator();
while (it.hasNext()) {
System.out.println(it.next());
}
}
}
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Jan 19, 2014
I have a game which is very simple: it is two images, and one needs to reach the other. Once it does, it resets. I have a class which holds the two images, and another which holds the game. My images class extends my game class. The problem I am having is that when I run the program, not one, but two frames appear. One is the perfect game, working perfectly, and the other is the game without images. I want the one that is the game without images to simply stop appearing. I believe it is appearing because my class that displays the image is extending the game class, but I can't not extend it because if I do I get a whole lot of bugs and errors.
Image class:
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.*;
[code]....
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May 5, 2014
I'm making a program that prints arrows of varying tail length, head width, and displacement.The shape algorithms are working properly, but the displacement isn't working. The first arrow has zero displacement, and the second one is supposed to be bigger and start the print at 10 spaces right and 5 spaces down from the default, but it's not working. I tried changing the displacement settings of the first arrow, and no changes happened, so I know that the positions aren't registering properly in general. How to pass the xAdj and yAdj (displacement) values? I think I have the empty space formula set up, but it's still not running.
Driver:
public class Driver
{
//default values
public static final int Arrow_Default_xAdj = 0;
public static final int Arrow_Default_yAdj = 0;
public static final int Arrow_Default_tail = 5;
public static final int Arrow_Default_width = 5;
[code]...
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May 15, 2015
I was wondering what the easiest way would be to keep track of everytime someone makes a new post on reddit (social media site, for those who don't know). I want the program to keep track of the number of posts made with a counter, but that's the easy part. How do I set up a program to actually communicate with and monitor reddit's servers in this manner?
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Oct 5, 2010
I am stuck trying to build a relatively "simple" GUI. The GUI should have one JComboBox that allows the user to pick from one of three locations. Then based on their choice, another JComboBox should be generated with another set of choices. The key is that the second ComboBox should have different choices depending on the selection made in the first one. So, in theory, the logic should be something like:
//create new JComboBox array of strings "locations"
//create new JComboBox array of strings "costToTravelThere"
//if user picks location 1 from the first ComboBox
then add the second ComboBox with options specific to that first location
else if user picks location 2 from first ComboBox
then add the second ComboBox with options specific to that second locatoin
I understand how to do the basic stuff, like create the JFrame and the actual panels and ComboBoxes, etc. What I don't understand is how to implement the second ComboBox dependent on the first one. I'm not very experience with Listeners and such, and I'm sure that's a big part of this.
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Apr 4, 2015
how to refer to objects die1 and die2 in the PairofDie class from the SnakeEyes class and what to do.
public class Die {
private final int MAX = 6;
private int faceValue;
private int sum;
//private int faceValue2;
public Die(){
faceValue = 1;
[code]....
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Mar 7, 2015
I have a class which connects with database and fills object with data. Method looks like this:
//in database class
void getData(anObject a, int id){
//connects with database
a.field1=get...
a.field2=get...
....
//disconnects
}
Now I want to use this method in anObject class, but I can't call it because I don't have created object jet. Is there any way to call this method?
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Aug 17, 2014
So I'm still trying to get to grips with Java, and like to understand exactly why I'm doing something, so that I am not just regurgitating the code, If I want to create an object from class "Apples", I would use the following, right?
Apples MyAppleObject = new Apples();
From what I understand, MyAppleObject is the new object name, new -> creates a new instance of it in memory, and Apples() is the onCreate method that is called
So question 1: (just a quick aside question) Can I create an object without calling Apples()? i.e.
Apples MyAppleObject = new;
Question 2: - PARTLY SOLVED - I discovered that (Button) is a way of typecasting, so I understand that line a little better. What I don't understand is why we don't need to initialize the object with "new"
I've now looked at a bit of android development and xml and those declarations are all together different, and I'm not sure why. I haven't found a single explanation for the difference in format.
Java Code:
Button Add;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Add = (Button) findViewById(R.id.button1); mh_sh_highlight_all('java'); So the Button object is declared above the onCreate method, but initialized afterwards I guess....
But instead of using Button Add = new Button() they use Add = (Button) findViewById(R.id.button1);
Question 3:
then In XML they use the following:
Java Code:
public*static*void*main(String[] args){
*********
********// Creates a DOM object in memory. Now you can access
********// data in the xml file
*********
********Document xmlDoc = getDocument("./src/tvshows5.xml"); mh_sh_highlight_all('java');
Once again, why didn't they have to use : Document xmlDoc = new Document()
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Nov 18, 2014
Having trouble adding Class (Dollar) objects to a HashSet (money), i have done this before with arraylists and i understand that HashSets are different in that they cannot contain duplicates. Currently when this code is compiled i am getting "null" printed when I run the "howFullDatWallet" method.
import java.util.*;
public class Wallet {
private HashSet<Dollar> money;
private int walletSize = 0;
private int walletFiller = 0;
/**
* Constructor for objects of class Pocket
*/
public Pocket(int walletCap)
[code]....
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Apr 13, 2014
Ok say you have
public class MyClass {
private int x = 5;
Object myObject = new Object();
public MyClass(){
}
}
When would the myObject be created? Before or after the constructor? And does this mean you can't pass
this into the parameters of that object?
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Oct 3, 2014
I've been unable to figure out how to access an objects data from another class. I ended up missing a lesson in java and haven't been able to catch up on this topic on my own through my textbook.
Error: has private access
Code:
public class TestCoffeeDrinker {
public static void main(String[] args) {
Coffee latte = new Coffee("Starbucks Tall Latte", 2.85);
Coffee mocha = new Coffee("Starbucks Grande Mocha", 3.95);
Coffee mcdonalds = new Coffee("McDonalds McCafe", 0.99);
System.out.println(mcdonalds.toString());
[Code]...
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Mar 26, 2014
I am trying to sort an ArrayList of objects with the comparator as I want to sort based on a certain value for each object. I understand I would need to override compareTo() in the objects class, is there any way I can get around also needing to override for all subclasses of the object?
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Jul 11, 2014
I read the document [URL] ....
But I am not able to get what is actual use of this in set ?
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Jan 24, 2014
I am asked to create a code that if a user enters 1 it will use the object natural comparison form ('default') as written in CompareTo method.But if he chooses to enter something else then another comparison is used.Maybe I just need to use 2 diff comparators? but then what;s the point of defining something as 'default'....
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Apr 23, 2014
I wrote a code from our text book for Pong. Im trying to figure out how to fill the ball with color. Im also wondering how to speed the ball up once there is contact with the paddle. The initial speed is ok but once contact is made with the paddle, it slows down. Makes it too easy to play. Here is my code so far. As far as the game goes, it works and is good. Just wanted to add a couple customizations.
Java Code:
package pong;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
[Code] .....
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Jun 9, 2014
What I'm trying to do is basically draw a Rectangle outline through left-click and then dragging the mouse to the size one wants.
After one has created this rectangle, the user can change the color of the rectangle through clicking the 3 sliders found on the top in the program. Upon the change in color, the rectangle should change from "g.drawRect" to "g.fillRect" and use the desired color.
I have the basic outline of the program done, but working with the last part (the color and changing of the Rectangle type after changing the color)
Is there like a "then" command in Java? Like: after you've done x, do y. That would make this heaps easier.
import java.awt.event.*;
import java.awt.*;
import java.applet.*;
//Diese Applikation offnet ein Fenster,
//in welchem durch einen gehaltenen linken Mouse Klick
//ein Reckteck gezeichnet wird
public class WhatIsTheProblem006 extends Applet
implements AdjustmentListener {
[Code] ....
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