I/O / Streams :: Unable To Write Sample Data Into Newly Created File
Nov 29, 2014
My code below creates the 2 files successfully, but it is not able to write the sample data into the newly created file. I can't figure out the reason why.
Another strange thing is that when I tried inserting System.out.println calls for debugging, nothing prints out.
I have a method that checks to see if a file exists, if so, it reads the data contained therein, if not it calls another method then exits.
public void checkLoadPreviousStationStatus() throws FileNotFoundException, IOException, ClassNotFoundException, EOFException, TempArrayOutOfBoundsException{ File f = new File(staFileName); //if station file already exists load the info if(f.exists() && !f.isDirectory()){
[Code] ....
My question, do I need to delete this file before exiting the method f.delete();? If not, what happens to it when I exit the method?
Memory recalled from a long ago taken c++ class: It's just reserving a memory location that will or will not be used isn't it? If nothing is stored in that location the reservation goes away right?
I am completing a USACO online problem and am trying to create a print writer to write to my file(ride.out). I did this:
PrintWriter out = new PrintWriter(new BufferedReader(new FileWriter("ride.out")));
However, a load of undefined constructor errors come up for PrintWriter(BufferedWriter) and BufferedWriter(FileWriter). I have imported java.io.* so I don't know what the issue is. This has worked before.
I have been going over my code line by line, over and over again for nearly and hour now...When I execute method `file.createNewFile()`, the method returns true and throws no exceptions. It even says that the file exists. However, the file is not created and cannot be accessed until the program has exited.
File portLib = new File(""); private class RememberPortAction extends AbstractMenuItemAction { methods... protected void actionPerformed() { LibraryCreator creator = new LibraryCreator(self, logger); File newPortLib;
I'm getting an IllegalArgumentException returned when I try to get a file using guava library.
I previously had the function working when the file was in a different location, before I switched to running JBehave, my steps run but it fails to find the resource, even after I've moved it.
The code being executed is (this worked previously before using JBehave):
The file I'm looking for is in the root folder for src/main/resources and also src/test/resources, previously I had it within a completely different location before I switched over to JBehave. I've tried it within a subdirectory in the same locations too.
I've recently updated the pom.xml to try to include the location required.
When I am trying to read data from BufferedReader and writing into excel using FileOutputStream object with POI APIs then i am getting the data in excel file in bad formats. you can check the log file and excel file attached for more information.
Here my problem is I cannot use BufferedWriter in place of FileOutputStream because POI class XSSFWorkbook only have one write method and we can only pass FileOutputStream class object there.
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
my idea is auto recognize when i put image like survey and that survey has shape box and it random area location and some shape box also character and number and can generated data that recognize in csv file.
So I am working on an ABV calculator for some practice, and one problem I am running into is that I am unable to set a JLabel properly on the top of the window that is created. It will display the text with no problem, but only on one column. Is there a way to center a JLabel across 2 columns? The label I am working with is titleL.
import javax.swing.*; import java.awt.*; import java.awt.event.*; import java.text.DecimalFormat; public class Beer_Calculator extends JFrame
Google shows me how to use file I/O, and how to use stdio, but not how to combine the two easily.
With my *nix command line I could "program file | tee savefile", but savefile holds the result of prior runs, gets read before I parse 'file', and this command line zero's out savefile before the program can read it.
The data is standard ASCII, I doubt I'll ever have 20k of data.
I'm trying to write data for three products to a random access file, but I have a problem. Each product has a code and a price. After writing them to my file, I want to get to the second field or product. I do this by getting the length for each record, and multiplying it by the field number I want to go to. I use the result for the seek() method of the RandomAccessFile object. It is giving me an EOFException, but when I use 0 for the seek method i get the data for the first poduct or field.
Java Code:
public static void main(String[] args) { final int RECORD_LENGTH = 16; try(RandomAccessFile productsOutput = new RandomAccessFile("C:UsersalfonsoDesktopBinaryTestRandom.ran", "rw")) { String[] codes = {"java", "jsps", "txtp"}; double[] prices = {49.5, 19.9, 29.9}; for(int i = 0; i < codes.length; i++) {
I have created a DefaultTableModel tablel as a Global variable. The table is then created and attached to a Grid bag layout. Then I want to call the table again in another method to add rows of data into it. Hopefully that makes sense.
So the addrow for the table is located in the final method private class CalcButtonListener implements ActionListener
When I debug the code, deftablemodel variable is carrying NULL data.
Also to make things even more complicated, The actual headers for the table aren't showing up,... not entirely sure why though.
I'm trying to right a GUI in swing, and as part of my program, I want to open a secondary window out of the main window when a mouse clicks on the main window. Then, once I click a button on the secondary window, I want that window to close and submit data to the main window (like an info form). I have almost figured out how to do this, except for one problem. By putting a variable inside my form window called "ready," and then in my main window running a loop that constantly checks if ready is true and doesn't proceed until its true, I can create the form window, modify the values in it (currently just one value called "difficulty" that's modified by a jSlider), and then when i click the "begin" button, ready is changed to true, the form window closes, and the main window can proceed. However, when I try to put the while loop checking the ready variable inside a mouseClicked method in the main window, the form window freezes when it opens, and you can't see any of its content or modify it in any way (you can't even close it).
Here is my code:
//form window class import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.event.*; public class formWindow extends JFrame { private JTextField instructions1;
I am creating a web application that runs on server X(unix) and it has another unix system mounted on it. I want to generate the file tree structure of this mounted unix file system and show it on to a web application so that users can select a file and move it onto this current unix machine.
I know this sounds stupid and you may want to say why cant we directly copy the file, I am doing a proof of concept and using this as a basis.
I am running this method but for some reason I am not able to find the data record, it keeps going to the catch. I have the data.txt file in the same directory as the java file.
public static Games[] gamesRecord(){ Games[] game = new Games[50]; try{ Scanner dataFile = new Scanner(new File("data.txt")); for(int i = 0; i > 50; i++){ game[i].title = dataFile.next(); game[i].releaseDate = dataFile.nextInt(); game[i].redistributions = dataFile.nextInt(); game[i].platformRelease = dataFile.next();
