I am not sure how to go about doing this, An ItemEvent.Selected constant is the hint given to me but i dont know how to start it.
My Array is : private ArrayList billItems = new ArrayList();
My method is : private void beverageJComboBoxItemStateChanged( ItemEvent event )
I have this piece of code, which adds marks into 2 different arrayLists, one for homework marks, and one for examination marks..
ArrayList<Double> homeworkMark = new ArrayList<Double>();
ArrayList<Double> examinationMark = new ArrayList<Double>();
boolean markCheck = true;
do{
//
the purpose of this try catch is to make sure that the entered mark is a valid number. If the program encounters an exception markCheck will become true and the loop will begin again asking the user to enter the marks. If the marks are all encountered correctly markCheck will be false and the loop will end.
try{
for (int i = 1; i <= amountAssignment; i++ ) {
sc.reset();
System.out.print("Homework Mark for Assignment " +(i) + ": ");
homeworkMark.add(sc.nextDouble());
System.out.print("Examination Mark for Assignment " + (i) + ": ");
examinationMark.add(sc.nextDouble());
markCheck = false;
[code]....
I was wanting to select an item in a comboBox and display it in a text field but all it's doing at the minute is retrieving the first item in the comboBox and placing that in the txt field
String value = (String) comboBoxEnv.getSelectedItem().toString();
if(comboBoxEnv.getSelectedItem()!= null){
txtTo.setText(value);
I have to use the company's login resource, which returns a login page for authentication after a browser/user page request; after successfully authenticated, the session attributes are set in a (remote) valued object (VO) invoked via servlet; then, such values are set in my (local) POJO.
I want to display the current user session attribute (see xChave below) and save it in database. How can I persist http User session attributes through the structure below?
Abstract Controller (just the main code):
public abstract class AbstractController<T> {
@Inject
private AbstractFacade<T> ejbFacade;
private Class<T> itemClass;
private T selected;
private Collection<T> items;
//GETTERS AND SETTERS OMMITED
public AbstractController(Class<T> itemClass) {
this.itemClass = itemClass;
}
[code]...
I made a simple test case using a ListView<String>.:
@FXML
ListView<String> listView2;
@Override
public void initialize(URL arg0, ResourceBundle arg1) {
listView2.getItems().clear();
[Code] ....
Using Java8 I see that I see this wrong behavior:
select 3 elements from the list: you'll see the log of the ChangeListener that tell you every time all items selected
remove 1 element from previous selection: you will not receive the notification!!!
remove the other two elements: only when the selection is empty you will see a new notification from changeListener...
I don't really get the concept of how I "insert" an item into an array. I get a cannot find symbol error when I try to. I think its because I'm losing focus. What sort of code would "insert" an item into an array? I just want a goal of conceptually how I would do it.
Anyways, here are the instructions for the exercise:
Write a new class method, insert, for the Item class that takes three arguments - an Item[] array, an Item newItem, and an int k - and inserts newItem into array at index k, discarding the last item of the array (that is, the item originally at index array.length - 1).
Here is the uneditable code:
public class Item {
private int myN;
public Item( int n ) {
myN = n;
}
public String toString()
[Code] ....
I get a cannot find symbol error, but I thought I was doing as I was supposed to. I thought you had to have an ArrayList to be able to insert or delete an item from an array. How can you take a primitive object, like an array, and insert something into it. My idea of it was a[i] would be replaced with a[i + 1]. I know I'm getting this concept wrong because that's what I tried to do.
I have a combobox with this PopupMenuListener. All works fine, except that the popupMenuWillBecomeInvisible method does not capture the selection made and neither does it show the selection.
PopupMenuListener pmlMqMessagePurged = new PopupMenuListener() {
@SuppressWarnings("unchecked")
public void popupMenuWillBecomeVisible(PopupMenuEvent arg0) {
try {
JdbcSqlServerDataSource ds = new JdbcSqlServerDataSource(
DbConnectionURL.UToolDbHostName, 0,
[Code] .....
The popupMenuWillBecomeInvisible does fire but the System.out.println() returns 'nul'l as answer to the value i have selected from the combobox.
New to Java Swing. What I am trying to achieve here is to create an instance of the class used to populate the DefaultListModel when a JList item is selected. All examples I have seen show how to return the text displayed in the JList which really is of no practical use.
I have achieved what I want to achieve in that I am successfuly creating the selected object within my ListCellRenderer class.
For the purpose of testing I am using a call to the JOptionPane.showMessageDialog method to display the id of the selected object.
So, I launch the JFrame, the JList is populated, I select an item from the JList and the id value is displayed in the prompt. All this works fine except for one thing.
When I click OK on the JOptionPane.showMessageDialog prompt, the prompt disappears and reappears. The system seems to be in a loop. It is behaving as if the change or click event handler on the JList keeps firing.
This happens even without the creation of the object:
BookEntry be = (BookEntry)list.getModel().getElementAt(list.getSelectedIndex());
I have scoured the code and object properties to see if I can figure out where this behaviour is coming from without success.
All there is in the JFrame design view is a single JList with a variable name of "list". Everything else is in code as below:
Here is the .java code. Its not that complex
import java.awt.Color;
import java.awt.Component;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JOptionPane;
import javax.swing.ListCellRenderer;
import javax.swing.DefaultListModel;
public class NewJFrame3 extends javax.swing.JFrame {
[Code] .....
How can I insert a new item at the middle of a BookList . I have also got a Book class represting Book objects and a inner class BookNode referencing them.
public void add(Book newBook)
{ BookNode newNode = new BookNode(newBook);
if (firstNode == null){
// no nodes in the list so add newNode at start
firstNode = newNode;
tempNode = newNode ; }
[Code] ....
//Add three red items to the list
LinkedList red= new LinkedList();
red.add(0,"1");
red.add(1,"2");
red.add(2,"3");
//create abc bucket to red items.
LinkedList abcred= new LinkedList();
red.remove(0);
//So how to insert removed item into abc buckets (similar to stack data structure)
I want to remove all red items and after that add to "abcred" using one by one. So, how to do that?
I have an array list in my GUI class of an aplication , the app reads in 3 fields from the user and saves these to an array list allowing the user to enter more fields to be added to the arraylist, when displaying back out to the user the same entry displays multiple times, for example if i entered , a,b,1 then c,d,2 and then e,f,3 into the app when i press my display button it would just throw back e,f,3 three times rater than the three different entries...
Constructor and instance variables
private String name;
private String number;
private int year;
private int count;
private ArrayList<StudentData> myList;
private StudentData myData;
[Code] .....
I am facing the following scenario:
1- Take information from distinct columns from two different tables - OK
2- Insert this information into a new table.
I have created a ArrayList and inserted all the information that I need but now I am trying to put this ArrayList into the new table and I am not sure how to do it. I have done research and tests but unsuccessfully.
Creating an Arraylist and adding item to that array, refer below code
ArrayList<String> sjarr = new ArrayList<String>();
Statement1:
String arritem1 = new String("First array item");
sjarr.add(arritem1);
Statement2:
String num = "text will decide";
sjarr.add(num);
Both adds the String item to array list but puzzling what makes the difference....
I managed to retrieve data, and set data in my own ways in which I like. But my problem is, if the file does not contain anything (fully empty), when I try to use my
set("", "");
method, it only sets the last one that is called.
Example:
set("section1", "section1Item");
set("section2", "section2Item");
set("section3", "section3Item");
Only section3 would get set, and not the others.
Otherwise, if the file contained a section already, then each section (section1, section2, section3) would get set.
Here's how I set the data to the file:
public static void set(String section, String data) {
files.openFileWriter();
files.file.delete();
reCreateFile();
String beforeItem = section + ":" + files.dataList.get(section);
if(files.hasReadData) {
[Code] ....
And here is how a retrieve the data and set them to my arraylist/hashmap:
public void getData() {
String line = null;
openFileReader();
StringBuffer sb = new StringBuffer();
[Code] ....
How 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 a JSF application with this code in the xhtml page:
<h:selectOneListbox id="selectProduct" size="10" style="width:10em; font-family:monospace" value="#{mybean.product}">
<f:selectItems value="#{mybean.products}" />
</h:selectOneListbox>
and the corresponding snippets of the Java code are:
// Class member variables
// ...
private String product;
private ArrayList<String> productValues;
private ArrayList<String> productLabels;
private SelectItem[] products;
// ... Various properties etc.
public String getLocation() { // Displayed on a page
[code]....
Most of this works correctly using only ArrayList SelectItem products without the two ArrayList and the separate SelectItem[], and the values and labels are put directly into products here. The menu works and I can select an item. However, I am unable to find the correct method for finding the index in the submit method,namely:
public void submit(ActionEvent e) {
showProduct = true;
prodNum = products.indexOf(product); // --- Here is the problem!
updateProduct();
}
which has not been changed here. In spite of trying out various ideas, prodNum always returns with -1, which means it cannot find the index of the selected product, where product is a String. Everything else seems to work correctly, and products.get(prodNum).getLabel() works if I manually give prodNum a valid index, but because it's -1 it fails.
I have a program where I have to open a file and then run a piece of code to do something with it. However since there are different files I want to run different pieces of code depending on the file. I have a JFileChooser setup and it works but I would like to have a something like an if else depending on the file extension.
View Replies View RelatedI managed to retrieve data, and set data in my own ways in which I like. But my problem is, if the file does not contain anything (fully empty), when I try to use my
set("", "");
method, it only sets the last one that is called.
Example:
set("section1", "section1Item");
set("section2", "section2Item");
set("section3", "section3Item");
Only section3 would get set, and not the others.
Otherwise, if the file contained a section already, then each section (section1, section2, section3) would get set.
Here's how I set the data to the file:
public static void set(String section, String data) {
files.openFileWriter();
files.file.delete();
reCreateFile();
String beforeItem = section + ":" + files.dataList.get(section);
[code]....
And here is how a retrieve the data and set them to my arraylist/hashmap:
public void getData() {
String line = null;
openFileReader();
StringBuffer sb = new StringBuffer();
[code]....
i've spend an hour or two, pasting fragments from tutorials and nothing changed.
Well - i have GUI, that have JComboBox with two elements:
String[] fedoras = { "Fedora 19", "Fedora 20" };
JComboBox fedora_list = new JComboBox(fedoras);
fedora_list.setSelectedIndex(0);
fedora_list.setBounds(120,170, 170,25);
fedora_list.addActionListener(this);
this.add(fedora_list);
Below i have normal button (named Update) with "update" set as ActionCommand. This button after clicked should check which value from list is selected and perform different operations for that elements. But it's harder than i thought.
Code for update button:
public void actionPerformed(ActionEvent e){
String cmd = e.getActionCommand();
(...)
else if ("update".equals(cmd)){
String selectedFedora = (String) fedora_list.getSelectedItem();
if (selectedFedora.equals("Fedora 19")) {
[code]....
- after user clicked Update button, button should check which value is selected in JComboBox (fedora_list).
- if Fedora 19 is selected and button clicked, then action in Xterm
- if Fedora 20 is selected, this same action in Xterm is performed, but for Fedora Linux 20
The problem is - i don't know hot to code Update button to check which value from fedora_list (JComboBox) is selected and perform other actions for every element on List.
This is the first time we are using 2 different classes. This is the code I have so far. What I am having trouble is doing the calculations and storing the value into the planet the user selected and keeping it going. I will attach the instructions ....
public class FakeGravity{
// Instance variables
private String planet;
private int VelocityDecay;
private double BouncinessFactor;
// default constructor
public FakeGravity(){
[Code] ....
Java Code:
ButtonGroup bg=new ButtonGroup();
JRadioButton choice1=new JRadioButton();
JRadioButton choice2=new JRadioButton();
JRadioButton choice3=new JRadioButton();
JRadioButton choice4=new JRadioButton();
bg.add(choice1);
bg.add(choice2);
bg.add(choice3);
bg.add(choice4); mh_sh_highlight_all('java');
here i coded out my radio button..i am confused how to get the selected radio button of string and match with another array of String..
import javax.swing.*; //import javax swing package
import java.awt.*; //import java awt package
import java.awt.event.*; //import java awt event package
public class JPizzaSize extends JFrame implements ActionListener //class name
{
final int SMALL = 7;
final int MEDIUM = 9;
[code]....
My variable numClicks counts all of the clicks on every button instead of each individual button and adds the cumulative total to the JTextField. What have I missed? If I click button1 twice, $14 appears in the text field, then if I click button2, $27 appears in the text field instead of $23. I though that numClicks would stop counting at the end of the curly bracket for that block of code?
Question 1: I am working on an assignment where I have to remove an item from a String array (see code below). When I try to remove an item after entering it I get the following error "java.lang.NullPointerException." I am not sure how to correct this error.
Question 2: In addition, I am having trouble figuring out how to count the number of occurrences of each string in the array and print the counts. I've been looking at other posts but they are more advanced and I have not yet learned how to use some of the tools they are referring to.
private void removeFlower(String flowerPack[]) {
// TODO: Remove a flower that is specified by the user
Scanner input=new Scanner(System.in);
System.out.println();
System.out.println("Please enter the name of the flower you would like to remove:
[Code] ....
How do I code this without having the need to use iterator? Code a Java method that accepts an ArrayList of integers and an integer. The method should delete all elements in the array list exactly divisible by the integer and return the number of remaining elements.
View Replies View RelatedOk I am trying to at this point read in a matrix from a txt file in the format with order of the matrix leading the matrix. Like this :
1
5
2
2 3
5 9
3
3 -2 4
-1 5 2
-3 6 4
4
2 4 5 6
0 3 6 9
0 0 9 8
0 0 0 5
4
2 4 5 6
0 0 0 0
0 0 9 8
0 0 0 5
My code then is supposed to read it in and store it as an Array of singly linked lists. I am having trouble with my code, I am only getting outputs where it is only storing the first line of the txt matrixs like so:
5.0
2.0 3.0
2.0 3.0
3.0 -2.0 4.0
3.0 -2.0 4.0
3.0 -2.0 4.0
2.0 4.0 5.0 6.0
2.0 4.0 5.0 6.0
2.0 4.0 5.0 6.0
2.0 4.0 5.0 6.0
2.0 4.0 5.0 6.0
2.0 4.0 5.0 6.0
2.0 4.0 5.0 6.0
2.0 4.0 5.0 6.0
Is there something obvious in my code that is making it only save the first lines and how can i fix it.
//import java tools
import java.io.*;
import java.util.Scanner;
//Test.java
//See readMe.txt file for implementation instructions
//input: "input.txt"
[code]...
Example : I have code and name but my code must start with the first letter of the inputed name if the 2 input is match it will be inserted into database
code = "A"001
name ="Angela"
= success this will inserted into database
else
code ="B"002
name="Angela"
=failed this will not inserted into database
else
code="A"003
name="Andy"
=success still accepts the input cause they have diff code number
What I am thinking on this was compare the code the name? if == it will be inserted but how do i get the 1st letter of the input name?