Java Array Update Without Using ArrayList - Add Values And Update Size?
Feb 9, 2015
I am trying to create an array list without using the built in arrayList class that java has. I need to start the array being empty with a length of 5. I then add objects to the array. I want to check if the array is full and if not add a value to the next empty space. Once the array is full I then need to create a second array that starts empty and with the length of the first array + 1.
The contents of the first array are then copied into the new array without using the built in copy classes java has and then the new array ends up containing 5 elements and one null space the first time round. The first array is then overwritten with the new array containing the 5 elements and the null space. The process then starts again adding values until the array is full which will be 1 more value then recreating the second array empty and the length of the first array + 1. This is my attempt at creating this but I have run into multiple problems where I get only the last value I added and the rest of the values are null:
public class MyArrayList {
public Object arrayList[];
public MyArrayList(Object[] arrayList) {
this.arrayList = arrayList;
I am trying out jsp and servlets now for the first time. I have to insert two data, car code and car name into a mysql table. I got those details using jsp but if I use form, it redirects to another page for insertion. I want the data to be inserted and still remain in same jsp page. I am thinking of using onClick from javascript but as I googled this many places have said it is a bad idea to use jsp inside javascript. If so how can we insert data to mysql table without redirecting to another page?
I have used netbeans to build my app. So there creating jTable is out of my control as that part was inside auto-generated code. I have just used the jTable.setValue().
My problem is, above method is inside a button click event. Updated values not displaying until the loops ends.
I'm trying to make a update page where you search for person info by their number then have the ability to change any info and save it back to the binary field. I have the search working but i don't know how to do the update,.here my code:
I have a GUI with several buttons and I'm using NetBeans GUI Builder to do. At the click of one of these I would like for it to open another frame containing a picture. So I associate a listener (actionPerformed) the button and when clicked it opens actually post the new frame.
In the new frame I waxed a JLabel and then I associate the image of the label. I saw that to do that NetBeans generates this code:
My problem is that the picture is overwritten several times during the execution of the program is not changed yet in the frame. That is, in the new frame is always displayed an old version of the image.
I have an image that is created every time I click on the button (it always has the same name and same path). Basically I have a generic tree on which I perform the operations (add, remove, etc..). When I click on the button I call a method that generates the image of the tree (using Graphviz). So I have one image that changes over the time...
How can I do so that the image is always up to date?
The Code:
package View; import javax.swing.Icon; import javax.swing.ImageIcon; import javax.swing.JLabel; public class AlberoIpotesi extends javax.swing.JFrame {
I have to build a server application. My issue is that it can never shutdown/restart. But I still need to update it.After some research I learned about OSGI where I can add/remove a bundle of code while the application is running. (update to a new version)Can I use JavaWS to update my OSGI application without having to close and restart it? I'm new to OSGI/JavaWS.
I have a flat file (.txt) with contents in a predefined format. I need to parse and look for a particular content and update it. How can i achieve this using Java.
I have been developing the web applications using struts (J2ee Technology) and i have developed few web applications and send to the production. now i want to add auto update capability of the application, means if any changes was made jsp/action class then application must have capability of updating the new code.
I am developing my first Java application and the database I use is MySQL. I have created two separate buttons; one to insert new data into my database and the other to update the database when changes are made.
Each button is working perfectly, but I now want to combine both functions into just the save button. Thus, whether I am entering new data or modifying existing data, the save button should use an IF ELSE condition to decide whether to use the INSERT or UPDATE command.
My problem is, how do I write this IF ELSE statement? What should be the condition? For example;
IF(what? ){ String sql ="Insert into Table1 (classID,className,counselorID,startDate,endDate) values (?,?,?,?,?)"; }ELSE{ String sql2 = "update Table1 set classID = '"+value1+"',className='"+value2+"',counselorID='"+value3+"',startDate='"+value4+"',endDate='"+value5+"' where classID = '"+value1+"'"; }
I'm working on a program to create a blackjack game using objects (one for card, deck. and hand). Withing my hand object I am trying to add cards to the hand but it is only adding the last card i try to add and giving null values for the the ones before.
class BlackJackHand { private BlackJackCard [] hand; public void addToHand(BlackJackCard c) { if (hand == null) { BlackJackCard [] tempHand = new BlackJackCard[1]; tempHand[0] = c; hand = tempHand;
[Code] ....
What I want this section to do is add cards to the current hand. I was intending for it the hand to be null at first and the if(hand == null) piece to add the card the first time and then the else piece would be used when the hand already has at leas one card. I want the else section to create a temporary array that is one larger than my current hand, copy the cards from the old hand to the new hand, and then add a new card to the last space before rewriting the old hand as what the temporary hand is.
The code I am using to test if the addToHand() is working is
class BlackJackTest { public static void main (String[]args) { BlackJackCard c1= new BlackJackCard(1,0); BlackJackCard c2= new BlackJackCard(1,4); BlackJackCard c3= new BlackJackCard(1,5); BlackJackHand h1 = new BlackJackHand();
[Code] .....
BlackJackCard has the parameters (int suit, int value)
This should print: ace of clubs 4 of clubs 5 of clubs
In my Java SWT application, I have few methods, that take longer time to complete. These methods has to be initiate and run as response to button click. There I want to implement progress bar to show the progress/status of long run method. Long run methods are Java Processes, in which it executes some command line functionality. (ex: run ls method in Linux).
Process p = Runtime.getRuntime.exec(command)
In progress bar status is set using setSelection method which takes int as argument. How to indicate the progress of process in progress bar, because I don't have int value to pass into setSelection method of progressbar.
The thing is if SITA is the name then I have to insert component to the particular envi tabs , if DEVB is the component I have to insert the component there. How can I do this I have done some code its inserting the data at the bottom og the XML .
I am creating a slot machine using eclipse. I am trying to get the "winnings" JTextField to be updated in a way so that when the random images have been selected it adds to the number that is already displayed in the JTextField as opposed to what it is doing at the minute which is just displaying how much was won on that particular spin. I am also struggling to set a code for when noting is won, nothing is added. My code is below.
public class User implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(unique = true, nullable = false) private int id;
public List<UserReason> getUserReasons() { return userReasons; } public void setUserReasons(List<UserReason> userReasons) { this.userReasons = userReasons; }
public UserReason addUserReason(UserReason userReason) { if (userReasons == null) { userReasons = new ArrayList<UserReason>();
[Code] ....
I want to be able to add userReason to the list, and that Hibernate will automatically update the reference between the parent & child object.
When using the above code, when trying to start the server, i'm getting the error message:
Repeated column in mapping for entity: com.commit.safebeyond.model.UserReason column: userId (should be mapped with insert="false" update="false")
Please notice that i mapped the userId in UserReasonPK with insertable = false, updatable = false.
If i change it, and add this on the User property in UserReason object, server is up, but when trying to insert new User I'm getting the following error:
I'm a beginner at java and am trying to code a basic pong game java applet. The code has no errors in it but when i run it the .png's do not come up in the window until its moved off screen. when the .png's are shown they do not update whatsoever. I thought the problem could be with the key-listener but even the ball (which moves independently of user input) does not move.
I've placed all the code from the 5 classes below. There's some unnecessary code in the background class but that's because I'm thinking of making the background scroll later on.
I have the below snipped of code that is giving me problems. The code is called when the user clicks on the "NEXT" button of the form. Why despite getting into the Lines 41-45 I am not able to update the BorderPane? Lines 30-39 appear to work as expected. In the case below there are 3 entries within the TreeMap. You can see this within the Output provided by NetBeans shown below.
I am writing a simple program in Java, where I call a method and pass some variables (namely, min and max) as arguments. This method is recursive, so the same arguments are again passed on in each recursive call.
I need to update these variables in recursive calls so that when the calling method uses them, it uses updated values. As it might sound confusing, here is sample code :
// Function 1. void func1() { //Call func2. func2 (int hd, int min, int max, Map<String, String> map); //Other stuff. } // Function 2.
[code]....
As you can see, min and max are updated after each recursive call returns, based on conditions. However, these changes aren't reflected in original min and max, which were used by func1 while calling func2. As far as I know, this happens due to call by value mechanism being used by Java while passing arguments. If I declare min and max as instance variables in the class, my problem is solved. But, I want to know whether there's any other way to update these variables so that changes in original min and max are reflected. Yes, I can return them as an array of 2 elements each time while returning, but it didn't seem a good solution to me.
So I have two related tables - Country (Master) Projects (Detail). Country has a OneToMany relationship with Projects. I put a link on my AllProjects.xhtml page. When tyhe link is clicked it uses a data model class to to display the current (clicked) project record (projectRecord object). After editing all the details, the UPDATE button calls a merge method in the DAO class. On the first attempt to update, nothing happens and the record is returned as it is with no errors. If I try updating again, I get:
Is the 'new' keyword in the entity class causing the Inser statement in the DAO because the JPA thinks I want to create a new object therefore invokes INSERT instead of UPDATE?
Lets say I have a program that is not in any way connected to the Internet. I post it for for downloading, but I know that I will need to update it fairly often. I don't want people to have to redownload the entire program, I just want to send out a patch to update it. How can I do this?
