I have a project where I am required to read and write a vector of bank account objects and I am struggling with this concept. I was able to figure it out when the accounts were not stored in a vector but now that I am dealing with vectorsThis is my best attempt. Even though I know it's wrong, what I am trying to do.write/read methods in main:
public static void readTrans()
{
textArea.setText("");
chooseFile(1);
try
{
FileInputStream fis = new FileInputStream(filename);
ObjectInputStream in = new ObjectInputStream(fis);
for (int index=0; index != fileIndex; index++)
have to create a file named Lab13.txt. In the file I have 10 random numbers. I have to import the 10 numbers and have to Multiply all the numbers from Lab13.txt by 10 and save all the new numbers a new file named Lab13_scale.txt. so if the number 10 is in lab13.txt it prints 100 to Lab13_scale.txt. how do i get it to Multiply Here is what I have:
I have copied a wav file as explained in [URL] ..... When trying to play my new file, it runs but no sound is hear. My reading and writing class is as explained in another post in the site:
This is the function that reads the file:
// read a wav file into this class public boolean read(DataInputStream inFile) { myData = null; byte[] tmpInt = new byte[4]; byte[] tmpShort = new byte[2];
[Code] ....
I can't hear the copied wav file, but still the wav file is correctly copied...
I've looked at multiple sources and everyone is saying different stuff. Which one should I be using? FileWriter/FileReader, other people was saying PrintWriter, and one even said : "Formatter" which is the one I'm doubting mostly. My purposes for writing files is for like saving maps, saving high scores, etc.
I have accountsData.txt file in my default package, this is the file it should be writing to and reading from.
There is an ATM class, which has the main in it. From here the program is supposed to work like an atm, you type in your account number and can withdraw or deposit. It is supposed to then write the changes to the file.
//Read from a file. public void loadAccounts(String inputFileName) throws IOException { Scanner fin = new Scanner(new File(inputFileName)); // Variables to store the values.[/color] int account = 0; double balance = 0.0;
public class Tester { public static void main(String[] args) { Product p1 = new Product(); p1.loadFromFile("Monitor.pr"); System.out.println("Actual: " + p1.toString()); System.out.println("Expected: Product [id=12345, name=Monitor, description=A freakin great monitor!]");
p1.setId(11111); p1.setName("another product"); p1.setDescription("Description of another product!");
[code]....
The expected output is what my program should be doing and the actual output is what it's doing instead. As you can see, my code works for the middle test. But I cannot understand why it won't load the first fileFor the second half, the id and the quantity are separated by a comma... I'm not really sure how to deal with that. As you can see, I tried using a delimiter, but it doesn't seem to be doing any good.
I'm having a bit of trouble with using the Scanner and the Printwriter. I start with a file like this (1 = amount of Houses in the file)
1 FOR SALE: Emmalaan 23 3051JC Rotterdam 7 rooms buyprice 300000 energylevel C
The user gets (let's say for simplicity) 3 options:
1. Add a House to the file, 2. Get all Houses which fullfil requirements (price, FOR SALE / SOLD etc.) and 3. Close the application.
This is how I start:
Scanner sc = new Scanner (System.in); while (!endLoop) { System.out.println("Make a choice); System.out.println("1) Add House"); System.out.println("2) Show Houses"); System.out.println("3) Exit"); int choice = sc.nextInt();
Then I have a switch for all of the three cases. I keep the scanner open, so Java can get the user input (house = for sale or sold, price = ... etc). If the user chose option 1, and all information needed is inputted and scanned, the House will be written to the file (which looks like what I typed above).
For this, I use try (PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("Makelaar.txt", false)))). This works perfectly (at least so it seems.)
If the user chose option 1, and all requirements are inputted and scanned, the Houses will be read (scanner) from the file and outputted. For this I use the same Scanner sc. This also works perfectly (so it seems atleast).
My problem is as follows: If a House has been added, I can only read the House(s) which were already in the file. Let's say I have added 2 houses, and there were from the start 3 houses. If option 2 is chosen, the first 3 houses will be scanned perfectly. An exception will be caught for the remaining 2 (just added) Houses. How can I solve this? I tried to close the Scanner, and reopening it, but apparently Java doesn't agree with this
I have a java code that should sort an array of names based on the last name. e.g jane a, jane b, jane z, jane d should be jane a, jane b, jane d, jane z. I have the following code but for some reasons, the s1 in the comparator method is always null.
public class ShuffleName { public static void sortNames(String[] names){ Arrays.sort( names, new Comparator<String>() { public int compare( String s1, String s2 ) { String s1last = s1.split("s+")[1]; String s2last = s2.split("s+")[1]; return s1last.compareTo(s2last);
I'm having some issues, trying to solve this problem in java. I want to print some election results, and i have to loop through a vector of objects and retrieve the partial sums of each party's seats for each constituency and the national results for each party. For now i can print the results per contituency, but i'm having problems in getting the national results. Like, adding the seats for labour party in Constituency A and B and C, etc, and print the sum. And do the same for conservative party.
This is what i have.
Java Code:
while (i < h.geral.size()) { show += "Constituency - " + ((Party) h.geral.elementAt(i)).getConstituency() + "
I am currently working on a java project, this involves me writing some code for a project, below are my attempts at coding so far:
/** * Prints out details of all animal in the zoo. * */ public void printAllAnimals() { System.out.println(" Details for all animals in Zoo " + zooId); System.out.println( "==================================");
[code]....
I currently cannot get the printallanimals() method to work as it should when executing the method printallanimals it just opens a filedialog box, when it is suppose to use the Collection object c,so that animals stored in the zoo can easily be checked.
I'm doing this assignment in which i have to write some products in csv file...but as u can see in csv file two products are same "Cooking Oil"..so any method that can add two same product's quantity and their amount and write them in file
import java.util.*; import java.io.*; public class SalesbyTransactionMonth{ private static final String fileName = "Data.txt"; private static final String fileName1 = "sales_by_trans_month.csv"; String line = "";
I have a big problem with writing Gauss Elimination in Java code. This is my homework, it's true. But I want to learn this, and I don't know how to bite this. I must realise some points:
1) Create new class - Gauss Elimination with two attributes (table A (nxn) and table B with vector (n));
2) Add new method "eliminate" which transform matrix A and parametr vectors B ;
3) Add new method "solve" which calculate inverse substitution.
I understand how vectors work I'm currently using one to store my id's from my txt file but how do you put them in a defaultComboBoxModel?
DefaultComboBoxModel defaultComboBoxModel = new DefaultComboBoxModel(); //declare a vector object that will hold a string (only thing that works with comboboxmodel Vector<String> myVector=new Vector<String>(); //try statement try{ FileReader fr = new FileReader(file);
[Code]...
Any example of how a vector is used with a defaultComboBoxModel so I can then use that to populate my JComboBox?
When I input "the" or "and" I always receive "its not here" as the output. Why is this? I also tried printing the values of v.get(i).other and the system printed null twice.
public class Translator { public String other; public Translator(String x) { x = other;
I'm having extreme difficulty in working with a Vector storing a column with a BigDecimal value, and converting that single value into a float. I'm not sure why the code was written this way, but basically, I'm working with something called a vector that has a single Big Decimal value/column (not sure what the correct terminology is), and I want to store that value in a float variable called "dp". However, I don't know how to convert from the Big Decimal to a float.
Code is below:
String s = ""; sql = "SELECT DiscountPercentRate FROM Attendees WHERE AttendeeId=" + attendeeId; Vector v2 = sqldb.getResults(sql); /*I know that sqldb.getResults(sql) returns a vector with a single BigDecimal column of 15.0, in the test example I'm using*/ if (!v2.isEmpty()) { Vector data2 = (Vector)v2.elementAt(0); if (!data2.isEmpty())
[Code] .....
In case you're wondering what the sqldb.getResults() method looks, like, here's a snippet of it - There's an else statement that triggers in my case, adding a BigDecimal column to a vector, and returns that vector.
Vector v = new Vector(); ... else { BigDecimal bd = rs.getBigDecimal(i); vCols.add(bd); } v.add(vCols); ... return v;
How can I take the single result of my SQL query in that Vector/Big Decimal thing, and turn that result into a float value?
im trying to create an insertion sort method for a vector. I know how to insertionsort for an array, but for a vector im having problems
Source code: PHP Code: package test; import java.util.*; import java.io.*; public class LinearSearch { public static void main (String[] args) { Vector myVector = new Vector();
[Code]...
I'm getting errors at lines 38 and 39 "Left-hand side of an assignment must be a variable". "Syntax-error(s) on token(s) misplaces contructor(s)". How can i fix them ??
class GVector { // TODO: declare a private array to save the vector coordinates // Creates a mathematical vector of d dimensions, initialized at 0 public GVector(int d) { // TODO: implementation
[Code] ....
I'm confused with what type of array I need to use to save the vector coordinates and what to put in Gvector. Is it a constructor?
calculate how long it would take to pay off a loan of 500 pounds if there was 10% interest monthly, and 100 pounds was paid each month. This code is in a pseudocode,
set months = 1 set balance = 500 set totalpaid = 0; while balance > 100 balance = balance - 100; set interest = balance * 0.1 balance = balance + interest totalpaid = totalpaid + 100 months = months + 1 endwhile totalpaid = totalpaid+balance display "you paid "+totalpaid display "It took you "+months+" months"
i have to write more than 100000 rows in a excel sheet (file size more than 20 MB) via java.
when i use XSSF, i am getting below Error.
java.lang.OutOfMemoryError: Java heap space at org.apache.xmlbeans.impl.store.Saver$TextSaver.resize(Saver.java:1592) at org.apache.xmlbeans.impl.store.Saver$TextSaver.preEmit(Saver.java:1223) at org.apache.xmlbeans.impl.store.Saver$TextSaver.emit(Saver.java:1144)
[Code]....
when i use HSSF , i am getting the below Error. java.lang.OutOfMemoryError: Java heap space
I have tried increasing the java heap size , by giving upto -Xms1500m -Xmx2048m
So I am trying to write the output of two different java class files to one txt file while the program runs. The file name is determined before the program is ran, through the command prompt as arguments. How can I get the second class file to edit the same txt file without running into compile errors.
For right now I'm just going to send everything that the second file outputs to a message String variable, so that the Main class outputs to the the text file. I still want to learn how to write to the same text file directly from the second class file.
import java.io.*; public class Test{ public static void main(String[] args) throws IOException{ int x; //create a new file internally called doc. But externally labelled the user input File doc = new File(args[0]); if (doc.exists()){
