Using Interface To Process A File And Return In Different Format
Jun 15, 2014
I'm working on an assignment where the program has to process a file and read every line then print it out in all caps. I'm pretty sure I have most of it written out, however, I am having trouble with my main method. I am supposed to call my go method in my FileProcessor class and have it use the StringProcessor interface to call my Upper class. I'm using an interface because I will be adding other classes later, but for now I am having trouble with implementing it all in my Driver class.
How do I declare a StringProcessor object in my Driver class and how can I use it so that it would create the file in all caps?
I have been researching the Iterator and making a class implement iterable. I have seen this example shown below and was wondering how I could change this so that iterable() is not called upon in the main. I would like to be able to make a method that returns an instance of a class that implements the Iterator interface hopefully an inner class. This is because my program will not have a main and will be supplied with a main that includes a new Object with will use the iterator method.
import java.util.*; public class IteratorDemo { public static void main(String args[]) { // Create an array list ArrayList al = new ArrayList(); // add elements to the array list al.add("C");
[Code] ....
This is all I have been able to understand from what I want to do. This does not work and this is what I am trying to achieve
public class MyArrayList implements Iterable { public static final int DEFAULT_SIZE = 5; public static final int EXPANSION = 5; private int capacity; private int size; private Object[] items;
So my assignment is to read these values from an input file which I previously created. The 10 values represent miles traveled and I convert them using some formula my prof gave me to get the total cost, and output both values to an output file.
My programming question is the first number on the input file isnt a mileage value its the number 10, which is the number of values to be processed, which we're supposed to use in order to control a for or while loop which we'll use to process the contents of the input file. How would I create a while or for loop and get it to skip the first value of the input file?
We're not allowed to use arrays for this assignment.
Also here's my code so far, and it says its not being able to find the file, I made sure the file name is exactly as saved, and its saved in the same directory as the java class that i created for this assignment so I don't see what the problem could be?
Here's my the class with the main method
import java.util.*; import java.io.*; public class QudratullahMommandi_3_07 { public static void main (String[]args)
QudratullahMommandi_3_07.java:17: error: unreported exception FileNotFoundException; must be caught or declared to be thrown Scanner input = new Scanner(inputSource); ^ 1 error
----jGRASP wedge2: exit code for process is 1. ----jGRASP: operation complete.
I created a main class called X and two Y and Z classes.
Y and Z implements Runnable classes.
class X contains a static array A that can be accessed in Y and Z.
The Run () method of the class Y reads an input file and populates the vector A.
The Run () method of the Z class uses data stored into the vector A to process some data.
The objective of using threads in this problem is: as the vector A is filled in the Run () method of class Y, the Run () method of the class Z will processing the received values in the vector A.
to do this I did the following calls in the main method of class X:
ObjectY y = new Y (); Thready thread = new Thread (objectY); threadY.start (); ObjectZ new Z = Z (); Threadz thread = new Thread (objectZ); threadZ.start ();
is that correct? I'm getting the expected results, but dont know if the code is parallelized in fact.
I am working on a management gui for a program. I have implemented the start server button. But now I need to get something working so that when I press stop server the javaw.exe process which is running the the other jar file is stopped and ended.
The gui is going to be using a javaw.exe as well and I don't want to end the entire thing.
I just want to end the javaw.exe process that is running the other jar file.
This is my code for starting it:
JButton btnNewButton_2 = new JButton("Start Server"); btnNewButton_2.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { Runtime rt = Runtime.getRuntime(); try { Process pr = rt.exec("java -jar DEDServer_release.jar");
[Code] ....
I just need to figure out what to do to stop it now.
It seemed to me that the bufferSize is limited so that I can only have it less than a default one, how to increase it?
My question now is how to increase the size of buffer in order to read a larger InputStream ? BufferedInputStream() default size is private static int defaultCharBufferSize = 8192; private static int defaultExpectedLineLength = 80;
How to make it larger and working? I tried to increase the defaultCharBufferSize to 500000000 but it did not work!
I want to use a method, which takes for example an int and also returns an integer. For example, if the the given integer is strong return a, if it is notstrong return b. How would you write that in a Code?
I want to use that in a more general way. I want to give a method mlong the value X of the type date and let it return an int. Type date consists of 3 int, one of them is the int month.
mlong should return an int depending on the X.moth. at the moment my code looks like this:
// File1: public class date { public int day; public int month; public int year; }
// File 2: public class monthlength { public int mlong(date X) { int t; t = X.month; if (t == 1 || t == 3 || t == 5 || t == 7 || t == 8 || t == 10 || t == 12) { return 31; } if(t == 4 || t == 6 || t == 9 || t == 11) {return 30;} } }
I'm wondering about the use of exceptions to handle errors that might occur during file I/O when the I/O is done by a method implementing an interface's method. The idea is for the interface to provide a uniform way for application code to read (and write, though I'm not addressing that in this post) a document from a file, given a File object that specifies the on-disk location of the document. The "document" can be an instance of any class the application programmer wants it to be, provided that it can be created from a file stored on disk. Here's the interface definition:
public interface DocumentRamrod<T> { public T openDocumentFile(File file) throws FileNotFoundException; }
A simple implementation, when T is a class that just holds a String, might look like this (Please overlook the fact that there is no call to the BufferedReader's close method, as it's not needed for this example.):
public class MyRamrod implements DocumentRamrod<OneLineOfText> { public OneLineOfText openDocumentFile(File file) throws FileNotFoundException { return new OneLineOfText(new BufferedReader(new FileReader(file)).readLine()); } }
But, that one line where the file is read (Line 5) might generate an IOException.To cope with it, I could add a try-catch to the implementation like this:
public class MyRamrod implements DocumentRamrod<OneLineOfText> { public OneLineOfText openDocumentFile(File file) throws FileNotFoundException { try { return new OneLineOfText(new BufferedReader(new FileReader(file)).readLine()); } catch (IOException ex) { Logger.getLogger(MyRamrod.class.getName()).log(Level.SEVERE, null, ex); } } }
Or, I could add that to the list of exceptions defined for the method in the interface, like this:
public interface DocumentRamrod<T> { public T openDocumentFile(File file) throws FileNotFoundException, IOException }
But that's where I'm getting nervous, as it makes me realize that, with an infinite number of possible implementations of openDocumentFile, I can't predict what all the exceptions thrown might be.should I have openDocumentFile simply throw Exception, and let the application programmer sort out which one(s) might actually be thrown, should I keep listing them as it become clear which ones are likely to be thrown, or should I not have openDocumentFile throw any exceptions and let the application programmer deal with it in the implementation of openDocumentFile (with try-catch blocks, etc.)? In Good Old C, I'd have passed back a null to indicate some general failure, with the various callers up the call-stack having to either deal with it or pass that back themselves (until some routine up the stack finally did deal with it), but that seems like an approach the whole exception mechanism was designed to avoid.
I'm thinking the right choice is to have openDocumentFile throw Exception, and let the application programmers decide which subclasses of Exception they really want to deal with. But I have learned to be humble about the things I think, where Java is concerned,
Is there anyway to format my input file "IF1.txt" into an excel/csv file, but with the content rearranged into a desired format? (all of this has to be done by a java program)
In Java® identifiers, you are allowed letters and numbers (also _ $£¢€ etc, but you should avoid them in normal identifiers). So you cannot have spaces. You cannot write public class Hello World because the javac tool will see World as a separate identifier and not understand what it means and will fail to compile the code. You must write public class HelloWorld instead. And because the class is labelled public you must call the source file Hello World. java. Since you can't have two classes with the same [fully‑qualified] name, you cannot write two public classes in the same source file.
“What about names of source files?” somebody will ask. Well, some file systems will permit spaces in file names; ext4 will and I suspect so will NTFS. Can you write file names with spaces in? You would have to have a different name of the class inside the file, because you can't have spaces, and you therefore cannot make the class public, but maybe you can write a package‑private class with a different name.
On ext4, you have to write out the name of the file and the shell will interpret the space as meaning there are two different file, so you have to escape the space.
campbell@campbellsComputer:~/java$ gedit My First Class.java // My First Class.java class Foo { public static void main(String... args) { System.out.println("Hello, World!"); } } campbell@campbellsComputer:~/java$ javac My First Class.java campbell@campbellsComputer:~/java$ java Foo
I want to store sql query in tree format in xml file.I wrote a code which split the code into different tokens and store it in xml file.I am storing keywords like "select",from,where etc as xmlelements and the values of these keywords as textnodes inside corresponding elements.When the query contains single single statement it works as i need.but when nested query occurs i want to store the nested query inside "where" element.In that case the code didn't works properly.I am hereby attaching the code. When i try to store the xmldata in "CreateFiles.xml" file ,the file is not displaying in the corresponding folder.what is the reason for that?
CreateXml.java /* * To change this template, choose Tools | Templates * and open the template in the editor. */ package querywork; import java.io.File; import java.io.StringReader; import java.io.StringWriter;
I am currently working on an application with java and I want to do is upload and download details in .xlsx file. Uploading process is successfully worked but the problem is that when I download the file .xlsx with details at opening the file it gives me the following message :
Excel cannot open the file '(filename)'.xlsx' because the file format or file extension is not valid. Verify that the file has not been corrupted and that the file extension matches the format of the file.
Well I want to generate a license key for my software product. I'm aware of Google's Guava Libraries for generating alpha numeric license keys. But I'm thinking it to do in a different way without using any such libraries or specifically guava libraries. Till now this is my plan that,
1. Get a MAC ID / IP Address of the system in which the application will be installed and ready for it's first use. 2. Store that MAC ID in a UNCOMMON File format in client's PC only. 3. And what should be the next step.?
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 have a tool that outputs a UTF8 file. This file is to serve as an output to another utility that functions with a UTF16 input.Is it possible to write a small script that will convert the UTF8 to UTF16 so that I can put it in a batch file.
I have a web service which is returning a string. I want to extend this web service so that it returns an xml based string. To begin with I am able to return xml based strings from a normal POJO class ....
The basic gist is it's "A program that reads in a text file that uses a specific input format and uses it to produce a formatted report for output."
Specifically :"For this lab you will write a Java program that produces a simple formatted report. The program will prompt the user to enter a file name. This file must contain information in a specific format (detailed below). Each "block" of the file contains information for one player in a competition -- the name of the player followed by a number of different scores that that player achieved. The program should find each player's average score, median score and best and worst scores and display them in a line on the final summary report. The program should also determine which player has the highest average score and which player has the lowest average score."
I get the following errors when I try and compile it:
Enter an input file name: Project11.txt Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException... -1 at java.util.ArrayList.elementData(Unknown Source) at java.util.ArrayList.get(Unknown Source) at Project11.getMedian(Project11.java:68) at Project11.main(Project11.java:27)
I get that the error(s) reside in lines 68 and 27, among problem other areas, but I'm not exactly sure how I can fix them.
Here's my code:
import java.io.*; import java.util.*; public class Project11 { public static void main(String[] args) throws IOException{ Scanner in = new Scanner(System.in); System.out.print("Enter an input file name: "); String input = in.nextLine();
The intent of the code is to read date from a file, does calculation and then displays that data in a table format on the screen. Then creates another file with those values:
Reads file: Beginningbalance.txt Displays Data with calculation Creates a file called "Newbalance.txt" with the following values:
111 251.41 222 402.00
With the way the code is written I can get it to create the file but it only displays one of the customers (111). I know that I need to create a loop but I am not sure how to build that. I tried creating another while loop and changing it to outFile but that was without success.
import java.io.*; import java.util.Scanner; import java.text.DecimalFormat; public class Output { public static void main(String[]args) throws IOException {
How do i take input values for TwoDPoint (which are objects) and return it back in numerical values also print them.
When i create an object in main method and pass values to my function of return type TwoDPoint,it gives error:- found int,int need TwoDPoiint,TwoDPoint.
// Here is what i tried to do:
Created class TwoDPoint that contains two fields x, y which are of type int. Defined another class TestTwoDPoint, where a main method is defined.In the main method created two TwoDPoint objects.
Then I modified the class TestTwoDPoint and add another function to it. This function takes two TwoDPoints as input and returns the TwoDPoint that is farthest from the point (0,0).
Then I added another function to TestTwoDPoint. This function takes two TwoDPoints as input and returns a new TwoDPoint whose x value is the sum of x values of the input TwoDPoint's and whose y value is the sum of the y values of the input TwoDPoint's.
class TwoDPoint { int x = 2; int y = 4; } class TestTwoDPoint { public static void main(String args[]) { TwoDPoint obj1 = new TwoDPoint(); System.out.println(obj1.x); System.out.println(obj1.y);
