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.
View RepliesLet's say I have a text file and in the text file exists file directories as such:
'assets/picture1.png'
'assets/picture2.png'
And so on...
How would I then read from this text file and then create those files using 'new File()'?
Here is my code:
private void getFiles() throws IOException{
files = new File[10];
Scanner scan = new Scanner(new File("files.dat"));
int count = -1;
[Code]....
It does print out those files, but it doesn't create them.
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 am trying to write a program that will generate a QR Code from an input text and also display some information about the input/output bits. So far I have created the frame and what to do next. And I'm not sure if I am on the right track since my level of programming is not that great. By the way, I am using zxing libraries from GitHub. I know, there are plenty of generators online for the QR Code, but that is not what I am looking for. As you can see on the attached image, I am more interested in the efficiency of encoding 2D data. Also, I noticed that almost all the online projects regarding 2D codes are for Android. Which is not very useful.
// QR Code Generator
package qrcode;
import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.EtchedBorder;
import javax.swing.border.TitledBorder;
[Code]....
I have a program where I have to open a file and then run a piece of code to do something with it. However since there are different files I want to run different pieces of code depending on the file. I have a JFileChooser setup and it works but I would like to have a something like an if else depending on the file extension.
View Replies View RelatedI need to read the contents of file A, and B and store it in file C by joining the contents of A and B and also counting the number of letters/characters present in it.
I've come up with this so far.
import java.io.FileInputstream;
import java.io.FileNotFoundException;
import java.io.IOException;
public class JavaApplication43{
public static putwrite(string fname) throws FileNotFoundException, IOException
[code]...
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 a program that reads lines of text, but some of the lines of text aren't applicable and break the program. I'd like to put a letter in front of the lines in the .txt file I want to use, such as a #.
I need to make an if loop that'll check for the first letter on the line being #, and use the line in the program if true and skip if false. I'm guessing a boolean variable would be useful here to be true or false depending on the presence of #, but I don't know how to only read the first letter of each line, how can I do this?
I know that it's possible to retrieve a line from a txt file but say for example my file looked like this:
staff id = 1
firstname
surname
age
staff id =2
firstname Kate
surname Hollar
age 33
staff id =3
firstname Daniel
surname Hong
age 21
It is possible to retrieve just the staff id's?
I have a problem with € symbol ... an application write a String content on the file system with following code:
out = new FileOutputStream(strPath + "import.xml");
out.write(trp.getTrpXMLModel().getBytes("ISO-8859-1"));
It's correctly wrote on the file system:
TT;Pierre-H€enri;;Orange Grove;zefezfezfez, Directeur Juridique;TT;;azdaz;01 53 33 56 87;ezfezfez;01 53 33 51 59;.....&ée&ée;;;;;;132;CORDIAL;aaa
But when the application try to read the previous file with following code:
BufferedReader in = new BufferedReader(new InputStreamReader(inStream,"ISO-8859-1"));
String line = in.readLine();
The application isn't able to properly read the symbol ... and return following line, without "€":
TT;Pierre-Henri;;Orange Grove;zefezfezfez, Directeur Juridique;TT;;azdaz;01 53 33 56 87;ezfezfez;01 53 33 51 59;.....&ée&ée;;;;;;132;CORDIAL;aaa
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 want to create hidden files, some sample code for doing this.
View Replies View RelatedI 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 .....
View Replies View RelatedI have a log file which goes like this..
INFO: Jul 07 00:00:15 DataSource 2zvw8p93107gev14wko86|34e51ca2: Total connections 4 idle 4 busy 0 unclosed orphans 0 pool unknown
PERFORMANCE: Jul 07 00:00:15 Garbage Collection: ParNew 5 51ms in 59 seconds. [SpeedoLoggingBean] Thread SpeedoBean
INFO: Jul 07 00:00:15 Speedo: 2,222,786K of 4,054,528K - 1,831,741K free, 4,952epm, 1 buffered, 216 threads, 49.1% CPU, permgen 173,731K of 262,144K - 88,412K free
Jul 7, 2014 12:00:15 AM org.geotools.data.wfs.v1_0_0.WFSTransactionState commit
SEVERE: number of fids inserted do not match number of fids returned by Transaction Response. Got:1 expected: 0
[code].....
What I need is to grab only the last hour data from this log file?
I have a binary file that has identifiers for the start of each record
You can see here that the record starts with 00 00 and the next record starts with 00 00 etc...
How do I read between these two points throughout the file?
RandomAccessFile database = new RandomAccessFile(databasePath, "r");
int start = 0;
int end = 0;
database.setLength(start);
database.seek(end);
The first start would be the start of the file, the next start would be the end of the first start and so on..
I'm just not sure how to put that into a loop.
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;
[code]....
My program creates a file but cannot write to it and i cannot figure out why.
How can i fix this code so that the FileOutputStream writes the String "Output" to the file HighScore.
public boolean ScoreWriter(int HighScore, int ScoreNum){
boolean writ = true;
System.out.println(HighScore + " " + ScoreNum);
try{
File ScoreFile = new File("HighScore");
if (!ScoreFile.exists()){
ScoreFile.createNewFile();
}else if (ScoreFile.exists()){
ScoreFile.delete();
ScoreFile.createNewFile();
[code].....
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 am checking how to do following task.
01. pickup the selected text file and read the line by line and output the text in to visual text pane.
what i did:.
01. I wrote code that read the text file and output in to jave console/ also some of the interface.
the code read txt file:
Java Code:
String fileName = "C:/Users/lakshan/Desktop/lawyer.txt";
File textFile = new File(fileName);
Scanner in = new Scanner (textFile);
while(in.hasNextLine()){
[code]....
so it will read any text file dynamically and output to the text pane in interface. I think scanner code must be execute after the select the file from the browser and set the scanned result in to variable. then later out put the var as string in some jswing component?
When my app starts up is it possible to create a blank xml file in the c drive? so I can use it later on down the line
View Replies View RelatedWhen 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.
public void readFile()throws IOException {
BufferedReader inputStream = null;
FileInputStream fis=null;
InputStreamReader isr = null;
//Blank workbook
XSSFWorkbook workbook = new XSSFWorkbook();
[Code] .....
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.
edit: bufferedreader? i give up(not literally)
If I'm using an xml file and the piece of data I want from the file looks like Staff id ="Test";
Is it something like this? Only seen two examples of it but I'm not sure they were reading from a file like myself.
Staff id = """ + Test + """;
here is code :
public final static void main(String[] args){
double d = 10.0 / -0;
if(d == Double.POSITIVE_INFINITY)
System.out.println("Positive infinity");
else
System.out.println("Negative infinity");
}
now ideally this might throw Arithmetic Exception.. but it prints positive infinity ,.. why.. ??
I believe i need Divide and Conquer method, maybe im wong..
I have to solve this:
x2+s(x)+200·x=N
N is given by the user, also A and B, which is the range of X.
but the range can be up to 1,000,000,000
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