I'm getting a DOMException, "HIERARCHY_REQUEST_ERR". I know that the problem is from the following code towards the bottom in my function, but I don't know how to deal with it. When I get rid of doc.appendChild(staff);, I get rid of the problem, but it obviously doesn't add the new entry to my root element.
Element staff = doc.createElement("Staff");
doc.appendChild(staff);
I am working on a project that requires me to build a database with random access file, representing products, the base product contains a name (about 30 characters), a price (double), and a quantity (integer). I have worked on this project for probably 15+ hours and have tried so many things and feel like I've barley made any progress...
The part i am really struggling with is taking the data from the text file and creating an object array with it using the product class. Once ive accomplished that, i have to use that data to create a random access file with the data.
Here is the base Product class that must be used to create the objects for the array.
public class Product { public String pName; public String stringName; public double price; public int quanity;
[Code] .....
And then here is the data from the text file that i must extract to use to create product objects.
These continue for about 40-50 entries, they are not separated by a blank line though i had to add those so it would display correctly, each entry is on its own line with name separated with spaces, then price after a comma, then quantity after the second comma.....
I am working on a project that requires me to build a database with random access file, representing products, the base product contains a name (about 30 characters), a price (double), and a quantity (integer). I have worked on this project for probably 15+ hours and have tried so many things and feel like I've barley made any progress...
The part i am really struggling with is taking the data from the text file and creating an object array with it using the product class. Once ive accomplished that, i have to use that data to create a random access file with the data.
Here is the base Product class that must be used to create the objects for the array.
public class Product { public String pName; public String stringName; public double price; public int quanity; //Constructor public Product( String pName, double price, int quanity )
[code]....
and then here is the data from the text file that i must extract to use to create product objects.
Dill Seed,938,34
Mustard Seed,100,64
Coriander Powder,924,18
Turmeric,836,80
Cinnamon (Ground Korintje),951,10
Cinnamon (Ground) Xtra Hi Oil (2x),614,31
Cinnamon (Ground) High Oil (1X),682,19
these continue for about 40-50 entries, they are not separated by a blank line though i had to add those so it would display correctly, each entry is on its own line with name separated with spaces, then price after a comma, then quanity after the second comma.....
I am new to java and I am creating a system that will ask the user to create a file that will store to a text file, Once the user created the file I have a class that will let the user input the subject name that has been created, However, I keep on getting this java.util.nosuchelementexception.Here's my code:
public void display_by_name() { String id, name,total; String key[]=new String[30]; String value[]=new String[30]; int i=0;
I need to write a program that will create an inventory file as a random access file. The problem that I am having is that among the things I need to add to the random access file is a "car name". Since random access files are byte based I don't know how I could possibly write and then read a string value.
Though have been playing around with my ebook but finding it difficult to get along with the topic PACKAGE&INTERFACES, I find it challenging to write a package file despite the book I currently studying and online tutorial.. so I want a more explanatory format to comprehend the piece cos without knowing it.
I'm having a problem with using the openCSV library when I create a JAR file. I'm currently using BlueJ to run my code. When I compile my program in there, I have no problems whatsoever and it runs great, yet when I create my program into a JAR file, my application doesn't work.
I would think that my problem is either stemming from faulty exception handling, although I don't understand why an input would work in the BlueJ environment, but not when using the JAR file. Or, perhaps the openCSV library isn't in a correct class path(I don't know if this is correct terminology).
I am working on a java logic game and I want it to be able to work on other people's Mac's, so I tried to figure out how to make it create a folder in which it can create files. The file creating is going fine however the folder never seems to create.Here is the code I attempted to use:
I need to check an existence of a file if it is already created or not but the problem is on my code I obviously making the file first before I am able to check if it exist or not.
File createFile = new File ("//path/name.txt");
I've read somewhere that that line should not make a file without the createFile.createNewFile(); but when I tested it and on my program, my program was creating the file even without the .createNewFile() method with that said. I'm confused on how would I be able to check an existence of a file without of course having it pre-created. here is the partial code:
File newFile = new File ("C:/Documents and Settings/Admin/Desktop/Keys.txt"); BufferedWriter write = new BufferedWriter (new FileWriter (newFile)); BufferedReader read = new BufferedReader (new FileReader (newFile));
if (newFile.exist()) { System.out.print("File is existing"); }
I'm currently working on a java project simply to learn java. So far, it creates a window and makes a properties file, or appends data to it if it already exists. The problem is that I'm not quite sure how to check if the file already exists to append data to it. I'm currently using a boolean (configCreated) that appends data when true, and creates a file when false. The problem is that this boolean is always false since it's at the beginning.
I'm trying to have the program create a .txt file for me but it is not working properly. It just keeps printing the exception error "The file could not be found" and exits the program.
// This program asks the user for input for a name, phone number and notes up to 200 entries. // It stores every contact in a file. Type 'h' for help while running this program.
import java.util.Scanner; import java.io.*; public class Phonebook { static Entry[] entryList = new Entry[200]; static int numEntries; public static void main(String[] args) {
[Code] ....
After running the code, I go into my workspace folder and I see that the file was created. What to do because running the program will always print "could not find the file".
i want to list files from resources folder like this:
@ManagedBean public class galley implements Serializable { private List<String> list; @PostConstruct public void init() { list = new ArrayList<String>();
[Code] ....
but it give me a null pointer exception on fList .... The directory of resources is :
how to create a tree data structure in java.I tried with a class consisting of node field and arraylist child nodes. but it does not satisfy the requirement.the requirement is that,
I want to create a TASK MANAGER for windows OS using java. Of course i am not expecting any code snippets, that is, what are the classes to be included and moreover HOW to do it.
Anyway I am creating a game for my A2 coursework, most commonly known as Checkers. I have completed my code and everything works as I had planned except that the CheckerBoard itself as well as the checkerpieces do not appear to be showing.
The section of were my board should be present is just a black space. Although my board does not appear to be displaying, all of the actions I perform on it such as clicking certain section produces the planned response, and although I've checked through my code I cannot work out what I've done wrong.
CheckerBoard content = new CheckerBoard(); // Sets the CheckerBoard values into the content to be used in the next line application.setContentPane(content); // Container holds the values together, Content pane of the CheckerBoard application.pack(); // Use preferred size of content to set size of application. Dimension screensize = Toolkit.getDefaultToolkit().getScreenSize(); application.setLocation( (screensize.width - application.getWidth())/2, (screensize.height - application.getHeight())/2 );
[Code] ....
I have noticed is that within the BoardComplete(), if you change the setBackground(Color.BLACK) to WHITE, it will change the colour of the section to white, but the checkboard is still unshown.
I'm finding common elements in a collection of arrays. This is my code so far.
import java.util.ArrayList; import java.util.List; public class CommonElements //< T extends Comparable<T> > { Comparable[] comparable; Comparable[] tempArr; Comparable[] tempArr1; Comparable[] newArray = new Comparable[tempArr.length]; int comparisonCount;
[code]....
I'm using this method to sort through my array. The method accepts a collection of arrays (of varying length and of any type) as input, the algorithm input should be no greater than n(k-1). I know I can solve it using a quadratic algorithm, but it won't meet the requirement of the assignment. I did have an idea of storing all my algorithm in one giant array. After storing as one giant array I was going to sort it. After sorting I was going to compare each array side by side and see if they are the same. Here is note my teacher provided.
Note About Testing You will need to develop several sets of test collections for testing your algorithm. The grading rubric mentions covering the case where all the test collections have the same length, as well as covering the case where the test collections are of different lengths. You will also need to think about what constitutes the worst case scenario for this algorithm, since only that scenario will make your analysis of total comparisons performed a meaningful one. You can use the formulas in the grading rubric to tell you how many comparisons you should expect in the quadratic and linear cases. For example, if you have 5 total collections (1 query collection and 4 test collections), each of which contains 10 elements, the total number of comparisons performed in the worst case should be: (k - 1)N2, which for k = 10 and N = 10 is: (5 - 1)102, or 400 comparisons. For the linear algorithm, you should only have N*(k - 1), which is 10*(5 - 1), or 40 comparisons.
Here is Q/A that my teacher provided:
1. Are the elements in the collections already sorted?The input collections may or may not be sorted. Don’t assume that they are sorted.
2. Can I sort the elements in the collections? Am I supposed to sort the elements in thecollections?Yes, you can sort the elements in the collections. It is not required that you do so, however..
3. If I sort the collections, should I count the element comparisons that are performed by the sorting algorithm?No. The only element comparisons you should count are the ones that are directly used to find the common elements. Ignore comparisons performed by any sorting algorithms you use.
4. How do I extract an individual collection from the Object[] collections argument of the findCommonElements method?You will need to typecast each collection as type Comparable[]. For example:Comparable[] currentCollection = (Comparable[])collections[i];
5. Why are we using a one-dimensional Object array instead of a two-dimensional array of type Comparable (e.g., Comparable[][])?In Java, arrays are treated as objects, so only a variable of type Object[] can contain arrays. A variable of type Comparable[] can only contain Comparable elements, not arrays. A variable of type Comparable[][] also can only store Comparable elements. Although it is possible to organize the elements such that all the elements at indexes [1][i], for example, are considered to comprise a collection, this is not the same as having an array that contains other arrays. The additional bookkeeping is required to keep a 2D array organized is more complex than simply performing the typecast described above.
6. Can I use other data structures besides arrays; e.g., HashMaps?No. Although it is easier from a programming perspective to use higher order data structures like HashMaps to find common elements, using these structures simply hides the details. If you were to examine the implementations of those structures, you would probably find that they use relatively inefficient algorithms such as sequential searches to find elements. Additionally, if you use library components, you have no way of counting the number of comparisons performed, since you don’t have access to the source code of those components.
7. Is this a trick question? I can’t think of any way to get below NlogN comparisons.It is not a trick question. It is possible to solve this problem using a number of comparisons proportional to (k – 1) * N.
I just want to ask about a kind inheritance.Let say I have an interface MachineCode.I also have different classes, Binary, Hex and Octal that implements MachineCode
Question: How can I prevent java to create an Object like this:
Binary bin = new Binary(); Hex hex = new Hex(); Octal octal = new Octal();
those declaration above must be compile error,
I want to create Objects of Binary, Hex, and Octal this way: MachineCode bin = new Binary(); MachineCode hex = new Hex(); MachineCode octal = new Octal();
