Right now i am working on some java using BlueJ and trying to insert and remove data from an arraylist through a public class or from a new class.
I want it to have it as like a database were you can add and remove data but have a limit of storing.
I have an ArrayList of tens of thousands of elements, and want to remove the items at a given set of sorted indices like {1,5,29,318,499,583}. It seems like this operation could be performed in linear time and space by first finding a cumulative sum of the shifts needed to move everything to their right positions and then shifting every item. On the other hand, removing and shifting one by one would seem to require many more shifts. Is there a way to do this in Java's ArrayList?
View Replies View RelatedHow do you remove from an ArrayList at a particular index then add back to that same index without the removal causing the ArrayList to compensate for the loss of them item and moving the empty space to the end of the array list?I've tried:
public void dischargePatient(int bedNumber) {
if (bedNumber < beds.size()) {
beds.remove(bedNumber);
}
}
But this moves the bed at bedNumber to the end of the ArrayList after removing the patient from the bed. How do I keep it at bedNumber?
I have to write a test class for a Contacts class called ContactTest and store the instances of Contacts created into a LinkedList.The ContactTest class should implement the addition andremoval of contacts to the Linked List and display its contents.
So far I have this, which stores the information entered into a Linked List, the problem is I don't know how I go about doing the addition and removal part.
Contacts Class
public class Contacts implements InterfaceContacts {
String fname;
String lname;
String phone;
String email;
//constructors
public Contacts( ){
this("****", "****", "****", "****");
[Code] ....
What I want to do is this, this is my first class:
public class Footballer {
int goals;
String surname= "";
String team="";
private static int counter=0;
private int dres;
}
(this is just the header of the class... And this is my second class, which contains an ArrayList of the first class:
public class FootballTeam{
String teamname="";
String league="";
ArrayList<Footballer> f;
}
And this is my third class which contains an ArrayList of the second class:
public class FootballLeague{
String leaguename="";
ArrayList<FootballTeam> ft;
}
What I want to do is, know how many of footballers are there in the league? Meaning how many of "f"s are in the "ft"... I remember from C++ it was easy, you just did it something like this: ft.f[i]; (where i is a position), then you'd go through each of them, if you wanted to do something with them, or just ask for it's length, if you needed to know how much footballers are there.
I'm trying this method to get the size of the array in the 2nd class, from the 3rd class (containing an ArrayList of classes of 2nd class, but no luck:
int counter=0;
for(int i=0;i<this.ft.size();i++) {
counter+=this.ft[i].f.size();
}
I'm getting this: Array required, but ArrayList<FootballTeam> found ---
I have extracted relevant parts of code and outputs, this is the only relevant code for this problem. There is a basic class called SalonData, which contains the fields refereed to. Original data rs. is obtained from an SQL extract, that is populating correctly.
public ArrayList<SalonData> salons=new ArrayList<SalonData>();
ArrayList<SalonData> loc2=new ArrayList<SalonData>();
SalonData salon=new SalonData();
salon.CardRecordID = rs.getString("CardRecordID");
salon.SalonName = rs.getString("Name");
[Code] ....
Printed results after this code is run;
Salons
2022XYZ PTY33 Smith Street319603 9773 2000
loc2
2022XYZ PTY33 Smith Street319603 9773 2000
The code was inteded to populate the phone number in arraylist "loc2", but based on the code, the phone number in arraylist "salons" for Location 2 should still be blank. Question is how did the phone number for this customer in arraylist salons, for Location 2, get populated?
What I want to do is this, this is my first class:
Java Code:
public class Footballer {
int goals;
String surname= "";
String team="";
private static int counter=0;
private int dres;
} mh_sh_highlight_all('java');
(this is just the header of the class, just how it looks)...
And this is my second class, which contains an ArrayList of the first class:
Java Code:
public class FootballTeam{
String teamname="";
String league="";
ArrayList<Footballer> f;
} mh_sh_highlight_all('java');
And this is my third class which contains an ArrayList of the second clas:
Java Code: public class FootballLeague{
String leaguename="";
ArrayList<FootballTeam> ft;
} mh_sh_highlight_all('java');
What I want to do is, know how many of footballers are there in the league? Meaning how many of "f"s are in the "ft"... I remember from C++ it was easy, you just did it something like this: ft.f[i]; (where i is a position), then you'd go through each of them, if you wanted to do something with them, or just ask for it's length, if you needed to know how much footballers are there.
If I declare and ArrayList as follows
"public static ArrayList<Media> mediaList = new ArrayList<Media>();"
How can i access it in another class (main class)?
package Projekt;
import Projekt.Media.rating;
public class MainTest {
static MediaHandler myreg ;
public static void main(String[] args) {
myreg.addMovie(title, playTime, year, seen, directory, path, rating.four, quality, subtitles, language, writer);
}
}
I also have the variables declared but didn't include them for readability.
we have an Arraylist<Tweet>, and this class is defined as followe: public class Tweet implements Comparable<Tweet>, Serializable. now if we implement the method comparteTo, then will it be sorted automatically? I want to sort this array by any insert.
View Replies View RelatedWhat is the difference between ArrayList and Vector class
View Replies View RelatedJava 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?
I'm trying to fill my jtable with an arraylist. The problem is the jtable is in an extended class and the arraylist in the mainGUI. Now how can I fill the jtable with the arraylist?
That's the arraylist in my MainGUI
BufferedReader in = null;
ArrayList<String> data = new ArrayList<String>();
try {
in = new BufferedReader(new FileReader("1.dat.txt"));
String str;
while ((str = in.readLine()) != null) {
data.add(str);
[Code] ....
My code runs and populates an arraylist. However my break statement, while stopping the loop ends up being added to the arraylist. And I'm not sure how to fix this error.
public static void main(String args[]) throws Exception
{
// declaring variables
String input = "";
// creating array list
ArrayList<String> nameList = new ArrayList<String>();
[Code] ....
I'm trying to create my own arraylist using Collection. My program doesn't do anything. Obviously, I haven't a clue.
import java.util.Collection;
import java.util.Iterator;
public class MyArrayList<T> implements java.util.Collection<T> {
private int size = 4;
private T[] mArray;
public MyArrayList(String[] args) {
[Code] ....
I'm trying to make a calendar that, when you click on the date, the result are stored in a map and visualized in a table that refers to a container.
I successfully created the map mechanism, but I have a problem on the list....
I add the rows in this way:
Object newItemId = container.addItem();
Item riga = container.getItem(newItemId);
riga.getItemProperty("Timestamp").setValue(fara);
riga.getItemProperty("Date").setValue(asa);
.
How can I delete a row in the list, when all I have in input is the "Timestamp" information, in a Long value?
BTY, I'm using NetBeans with Vaadin extension
My remove(item E) method is working fine if I remove an item that is in the list. However, it has an error when I try to remove an item which is not on the list!
Linked List Class
import java.util.NoSuchElementException;
public class LinkedList<E>
{
private Node<E> head; // head node of the list
private int size = 0; // number of elements that have been added to the list
// Returns the element at a specific list index.
// Big-O: O(n) (due to the nodeAt call, which must traverse the list)
public E get(int index)
[code]...
I want my jSpinner value "0" to be removed on button click. and I want my jSpinner and jFormattedTextfield and jTextfield value "0" to be Highlighted(e.g: like highlighted by mouse double click) on button click.By removed I mean: nothing to be in the jSpinner. empty as any textfield. the jSpinner default value is 0 and on Click I want the value of the jSpinner to be removed and Highlighted, I need both examples code.
View Replies View Related1. BALL
import javax.swing.Timer;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class Ball extends JPanel {
private int delay = 10;
private Timer timer = new Timer(delay, new TimerListener());
private int x = 0; private int y = 0;
[Code] ...
How can I remove the ActionListener from the buttons of my application after i have got something happen.
Please consider the following application:
Java Code:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Exer1218659 extends JFrame {
private String[] textButtons;
private Container contents;
[Code] .....
After the line 37 executes I expect that the ActionHandler (ah) will be removed from all of the buttons but this do not happen, then all the remaining button still responding to the clicks. Where is the problem in my code.
My program gives me an error when I try to "digUp" the purse. The error appears in the purse class.
import java.io.*;
public class Purse
{
//Fields
public double gp;
public double gold;
public double silver;
public double copper;
public double platinum;
public static final double GOLD_VALUE = 1;
[Code] ....
In the digUpPurse() method, it tells me
java.lang.NullPointerException
null
What this means.
I have a prob with my coding..Here it is :
private boolean chk_akhiran(String pkata) {
String tempkata = new String();
boolean wujud = false, status = false;
{
for (int i = 0; i < akhir + 1; i++) {
tempkata = Suffix[i]; // list of suffix that possible to be removed
[Code] ....
Example : "katakan" will produce "katak" but at the same time possible root word that can be produced is "kata"
in Suffix [i] i have a suffix "an" and "kan"..it's stop when meets suffix "an" bcoz "an" is above "kan" in a list .. How to get another possible root word....
if one address point on another address. so set and get methods will be less efficient then an array, but add or remove will be more efficient by a linked list ? a linked list also inherit from queue so if i add an elemnt via "addFirst" function . where its adding the element ? to the right most or left most ?
if i have for example :
here [ ] --> [ ] --> [ ] --> [ ] -->[ ] or here
linked list its FIFO so the head will be the right most ?
Edit : its confused me a little bit but i understood now .so it will be at the left most. its actually ordered . not like the stack which is LIFO.
How can I remove the light blue border? I tried everything that I know [URL]
View Replies View RelatedI'm just a java beginner. I've spent a lot of time installing and configuring software. I'm using Netbeans 7.3 on Windows 7, 64 bit. Recently, I downloaded opencsv from sourceforge.
With no previous experience adding libraries, I read a blog post on adding the library. I think that I then:
Start a new project.
Right click on libraries
Add jar/folder
Gave the temporary path to the .jar file
After, I read the blog post again, and realized I'd missed it. This time I did:
Right click library, Add library, Create library
However, I kept getting a message that the same library already existed. If I do the first process above, I will find the same library.
However, I see no way in Netbeans to remove it. I've deleted the test projects. And started a new one. But the library now exists for all projects it seems.
I've grepped all the files under the Netbean directory, searching for "opencsv", but found nothing. The only things in the Windows registry were locations of files.
How can I delete this library permanently from Netbeans? Short of, uninstall, then reinstall? Is there a way to list all the libraries that Netbeans has?
I basically need to allow the user to add or remove toppings on the pizza once it is created. I am new to code (steps included). We are supposed to use enums and sets.
package pizza;
public class Pizza {
// Declare enums
public enum Size{
SMALL,
MEDIUM,
LARGE,
JUMBO
[code]....
I started this this is what I have currently I have an error here:
private Set<Topping> setOfToppings = new EnumSet<Topping>(Topping.class);
I am sure it is because I haven't set it up correctly.
Is there a better way to remove null values from an array than what I have tried? This works just fine, but I just get the feeling that there is a better way to do this, without using the JCF.
private static String[] removeNullValues(String[] list){
int count = 0;
for(int i = 0; i < list.length; i++){
if(list[i] == null)
count++;
[Code] ....
I technically dont need to remove the null values for the project that I'm working on (since I just print it out and I can avoid null values with a simple statement like
if(update[i] != null) SOP(update[i])
),
but I'm just curious.