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
I need to write a program that, when a button is pressed, will add the user input to a table AND write it to a sequential data file. I have everything done accept for how to write the data sequentially(all input data on the same line in the file). The following is part of the code:
private void submitButtonActionPerformed(java.awt.event.ActionEvent evt) { DefaultTableModel dtm = (DefaultTableModel)jTable1.getModel(); dtm.addRow(new Object[]{donorName.getText(),charityName.getText(),donationAmmount.getText()}); //Adds user input to the table try { FileWriter writer = new FileWriter("FundraisingInformation.txt",true);//Creates file or adds to it BufferedWriter bw = new BufferedWriter(writer);
[code].....
I would need the file output to be in the following format:
donorName charityName donationAmmount
As I said, using the .write(bw) i know how to make it look like:
I am creating a car simulator that simulators the odometer and fuel gauge on a car. I want to print the results to a text file but it seems to be printing only the last two lines instead of all of them. How can I make it so it doesn't overwrite the previous input?
Here's my main method:
public static void main(String[] args) throws FileNotFoundException { CarInstrumentSimulator carInstrumentSimulator = new CarInstrumentSimulator(); FuelGauge gas = carInstrumentSimulator.new FuelGauge();
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 program which consist of several classes. The program reads a pom file and parses the data and then writes the data to a static table. The issue I'm having is with writing my LIB file data to my table. In the HtmlDataTable Class Im trying to write the files that are read in the lib directory to the table. My table currently consist of 3 columns (missing jar files,Lib Directory files, and POM file data) currently Im only able to write the missing jar files data to my table. In the HtmlDataTable class there is a for statement where I write the missing jar file data to my table. Im also trying to write the contents of the Lib directory within this statement as well. This is where I'm having my issue. My other classes consist of a SAX parser which parses the xml file, a class that creates my static table and a class that compares the jar files in my lib directory to the jar files in my pom file. . Theres a lot of code so I included the parts I felt were useful. If needed I can include the other classes as well.
public class ReadPomFile extends DefaultHandler { public static void main(String[] args) { try { // obtain a SAX based parser to parse XML document
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 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
I have a code that clear old text then add new text to text file afterthat download the file but the problem my code dose not add new text
FileInputStream fileToDownload ; private static final int BYTES_DOWNLOAD = 1024; response.setContentType("text/plain"); String name = request.getParameter("n"); String text = new String(request.getParameter("text").getBytes("iso-8859-1"), "UTF-8");
[Code] ....
How to clear old text then add new text to text file
I would like to create a component to detect the file being modify before process.is it the right way to detect the file modification based on file size value?
Below are the flow:
1. Get the file size of a file 2. Used file size value encrypt it with MD5 algorithm, and say it generated us encrypted value "0123sdf" 3. to avoid user modify the file content, before file process, we take the file and do the encryption with md5 again, if it return value "0123sdf", then we are sure it doesn't have modification.
my question: a. is it the right approach to detect file modification? b. what the library advise to use or using java.security.DigestInputStream will do?
I am looking for a pure java api that can read metadata from an mp4 file, I have looked online but all apis I found are wrappers to native code. How to read mp4 with java .....
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 do most of my file I/O with {Scanner} for input and {PrintWriter} for output. I've got lots of places in my code that looks like:
Scanner source = new Scanner( new File( sourceName)); PrintWriter dstntn = new PrintWriter( new BufferedWriter( new FileWriter( dstntnName)));
But when I call the constructor for {PrintWriter} up above, it overwrites whatever the original contents of the file designated by {dstntnName} were, doesn't it? Is there a way to call the constructor so that any future writes to it simply append to the original contents, instead of overwriting them?
I have to divide a text file into blocks of 128 bits. I think i must use the ByteArrayInputStream and ByteArrayOutputStream classes. is there any website showing how to user these two ByteArrayInputStream and ByteArrayOutputStream classes in detail. or it would be much better if you could show me a portion of the code.
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.
