I/O / Streams :: File Not Created Until Program Exit
Aug 28, 2014
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;
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 just want to know how I can get my program to end when the user inputs "0." By using: System.exit(0);
import java.util.Scanner; public class TestCode { public static void main (String [ ]args ) { Scanner console =new Scanner(System.in); System.out.println("To exit program input 0"); for (int y = 1; y < 11; y++ ){ // Executes output 10 times
Description of the program: read a sequence of positive integers from terminal. When user types
-1, the program will print out the largest number and exit.
Program mid.java import java.util.Scanner; public class test { public static int num; public static void main (String[] args) { Scanner in = new Scanner(System.in); num = in.nextInt(); int large = num; while(num > 0); { if(0 > num && num > large) large = num; } System.out.println("The largest number is : " + large); } }
This is my first java program,i am using eclipse IDE-----
package day1.example;
public class MyFirstJava {
/** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub System.out.println("hi"); } }
When i saved it,it shows no error.when i run it then a pop-up says "could not find the main class.the program will exit" and in the console it says---
java.lang.UnsupportedClassVersionError: day1/example/MyFirstJava : Unsupported major.minor version 51.0 at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(Unknown Source) at java.security.SecureClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.access$000(Unknown Source)
My question is how can I make the program repeat until the user enters the number 4 to exit?
/** * Write an application for a furniture company; the program determines the price of a table. Ask the user to choose 1 for pine, 2 for oak, or 3 for mahogany. The output is the name of the wood chosen as well as the price of the table. Pine table cost $100, oak tables cost $225, and mahogany table cost $310. Also ask the user to specify a
(1) large table or a (2) small table.
Add $35 to the price of any large table and add nothing to the price for a small table. Display the output. Your program must repeat until the user chooses to exit.
*/ import java.util.Scanner; public class Wood { public static void main(String[] args) { Scanner input = new Scanner (System.in); System.out.println ("Table Prices");
My homework assignment is: Using a do-while statement, write a Java program that continuously requests a grade to be entered. If the grade is less than 0 or greater than 100, your program should display an appropriate message informing the user that an invalid grade has been entered; a valid grade should be added to a total. When a grade of 999 is entered, the program should exit the repetition loop and compute and display the average of the valid grades entered. Run the program on your computer and verify the program using appropriate test data.
When I run it, I don't get the correct average. I know that i'm supposed to enter 999 to exit the loop and to display the average, but 999 is being added with the loop. I'm not sure how to make it not do that.
//stephanie import java.util.Scanner; public class gradeAverage { public static void main(String[] args)
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 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 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 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.
