Collection Sort When Getting Array Values From Text File?
Nov 27, 2014
I working on a bank program that gets a user id, name and balance from a text file. I need to be able to sort based on each field. I'm using Collection.sort and Comparator. I'm using String[] array = file.toFile().list(); to get the values for the array from the text file. I can't figure out how to make this into an arraylist. I understand the concept when hardcoding the data but having trouble doing it from a text file.
I am trying to read numeric values from a text file into an array. This is what i have so far but when i compile it, it doesn't run and give me a result.
import java.io.File; import java.io.FileNotFoundException; import java.io.IOException; import java.io.PrintWriter; import java.util.Scanner; public class question2_17110538 {
Use the sort method of the arrays class to sort the values in the array, and print the median value(the 50th value) on the console followed by a blank line. Then, test this enhancement. Print the 9th value of the array on the console and every 9th value after that. Then, test this enhancement.
import java.util.Arrays; public class ArrayTestApp { public static void main(String[] args) { double [] arrayTest = new double[99]; //adding random number to each element in the array for(int i=0; i<arrayTest.length; i++) arrayTest[i] = 100.0*Math.random();
[Code] ....
OUTPUT
run:
The average is: 49.842845462514944 The median is: 49.68753724038633 The 9th value is: 2.599530043466969 The 9th value is: 11.486193141397095 The 9th value is: 20.14206270200648
I'm doing a project with very defined requirements. Input and output will be done to and from a file. Both the input and output files should have the same format. Each file will consist of a series of lines formatted as follows:
Year Rank Artist Title
That is, each line of the file will consist of the year, rank, artist, and title of a single song, with each of the fields separated by tabs ( ). Output files must maintain this format—you should be able to use the output file of one run of the program as the input to another run.
The first part of my project is to make a Song class, with 6 methods:
public static Song parse(String s) { //Parse a string of the form “Year Rank Artist Title” and create a Song object with the given values. } public int getYear() { //returns the year of the song } public int getRank() { //returns the rank of the song
[Code] .....
So far, I have worked out my Song class like this:
Java Code:
import java.util.Scanner; public class Song { private int year; private int rank; private String artist; private String title;
[Code] ....
I know there's definitely a problem with my parsing, as I am getting the
Exception in thread "main" java.util.NoSuchElementException
when I attempt to input a test String at my variables.
Should I try using StringTokenizer and Integer.parseInt()? I think that perhaps the reason why an error is occuring is because the String is being parsed into Strings and there are no int values to be inputted into the year and rank variables.
I am working on a class that sorts and matches items in a collection of arrays. In the end, elements common to all 3 arrays should be printed. The idea is that as the first array is compared to the second it stores the matched items in tempArray. When all items are compared the tempArray should overwrite the checked array, and the process continues until all arrays are checked. I have set all the checking in a do loop that should run while the value is <= to the array length. This allows all items in the reference array to be checked. I get an index out of bounds message but not where I would expect it. I have tried varying the condition in the do while loop in the match method, but it did not change the result. There may be other issues I have not addressed with solving the algorithm, but this one has me stumped and I am not able to progress.
package testing; public class TestMatchMain { public static void main(String[] args) { Comparable[] innerCollection0 = {1,2,3,4,5}; Comparable[] innerCollection1 = {1,1,5,6,7};
I'm supposed to write a program, which reads float numbers from a file, puts them in an array and sorts the array. After that I'm suppose to add the numbers so that when I add the 1 and 2 number of the array, I'm suppose to save the sum on the position of number 1, then I add number 3 and 4 and save the sum on position 2 etc. Also if my array has an uneven number of floats it's suppose to add the last 3 and not 2 numbers in the last iteration. The problem is the method throws an ArrayOutOfBounds Exception but I can't seem to find my mistake.
That's the second method. The first one just stores the sum in another variable and then returns it. Also is there a way in that I can Scanner/File/array etc. and initialize the array only once so I don't write the same code two times like it is now.
package sumOfFloats;
import java.io.File; import java.io.FileNotFoundException; import java.util.Arrays; import java.util.Scanner; public class SumOfFloats { public static float sumFloats() throws FileNotFoundException{
How can I read a text file present in my local directory say (C://test.txt) , iterate and populate the values of test.txt into a text area of the JSP page?
Contents in the test.txt file: username:test password:test123 domain:test321 DBname:testDB
So I'm trying to read 11 values from a text file, each value on a separate line. The first value I use as loop control to run through calculations on the other ten and finally output both the numbers and the calculations to the console and an output file. I'm not getting a compiler error or a runtime error but my loop seems to stop after reading the first line. It also doesnt seem to be writing to my output file but does create it when I run the program. This is what my text file looks like
import java.util.*; import java.io.*; public class assignment7scratch { Toolkit_General toolKit = new Toolkit_General(); public static void main (String[]args)throws IOException
[Code] .....
so I dont get an error but this is what my output looks like
----jGRASP exec: java assignment7scratch
This program reads a list of values representing number of miles driven by individuals. It will output the dollar amount their rental cars cost.
Number of miles traveled on the left as well as amount reimbursed on the right
----------------------------------------------- Miles Driven Amount reimbursed 150.427.072
----jGRASP: operation complete.
it also doesn't write anything to my output file, though it does create one.
I am working on a project that requires me to build a database with random access file, representing products, the base product contains a name (about 30 characters), a price (double), and a quantity (integer). I have worked on this project for probably 15+ hours and have tried so many things and feel like I've barley made any progress...
The part i am really struggling with is taking the data from the text file and creating an object array with it using the product class. Once ive accomplished that, i have to use that data to create a random access file with the data.
Here is the base Product class that must be used to create the objects for the array.
public class Product { public String pName; public String stringName; public double price; public int quanity;
[Code] .....
And then here is the data from the text file that i must extract to use to create product objects.
These continue for about 40-50 entries, they are not separated by a blank line though i had to add those so it would display correctly, each entry is on its own line with name separated with spaces, then price after a comma, then quantity after the second comma.....
I am working on a project that requires me to build a database with random access file, representing products, the base product contains a name (about 30 characters), a price (double), and a quantity (integer). I have worked on this project for probably 15+ hours and have tried so many things and feel like I've barley made any progress...
The part i am really struggling with is taking the data from the text file and creating an object array with it using the product class. Once ive accomplished that, i have to use that data to create a random access file with the data. Here is the base Product class that must be used to create the objects for the array.
public class Product { public String pName; public String stringName; public double price; public int quanity;
[Code]...
these continue for about 40-50 entries, they are not seperated by a blank line though i had to add those so it would display correctly, each entry is on its own line with name seperated with spaces, then price after a comma, then quanity after the second comma.....
I am working on a project that requires me to build a database with random access file, representing products, the base product contains a name (about 30 characters), a price (double), and a quantity (integer). I have worked on this project for probably 15+ hours and have tried so many things and feel like I've barley made any progress...
The part i am really struggling with is taking the data from the text file and creating an object array with it using the product class. Once ive accomplished that, i have to use that data to create a random access file with the data.
Here is the base Product class that must be used to create the objects for the array.
public class Product { public String pName; public String stringName; public double price; public int quanity; //Constructor public Product( String pName, double price, int quanity )
[code]....
and then here is the data from the text file that i must extract to use to create product objects.
Dill Seed,938,34
Mustard Seed,100,64
Coriander Powder,924,18
Turmeric,836,80
Cinnamon (Ground Korintje),951,10
Cinnamon (Ground) Xtra Hi Oil (2x),614,31
Cinnamon (Ground) High Oil (1X),682,19
these continue for about 40-50 entries, they are not separated by a blank line though i had to add those so it would display correctly, each entry is on its own line with name separated with spaces, then price after a comma, then quanity after the second comma.....
New to programming. Am supposed to create a program that reads a text file (of integers) and computes a series of computations on these integers. I don't have the code for the integers in my code yet, (i know how to do those), but am struggling getting the array to simply print in the print writer. I have the user select a text file, read the file with a scanner, and then save the computations done from my code into another file. specifically, the problem is as follows: Write a program that uses a file chooser dialog to select a file containing some integers. The file contains an integer N followed by N integers. The program then uses a file chooser dialog to let the user specify the name and location of an output file to write results to.The data written to the output file will be as follows
(1) The original list of N numbers from the input file, (2) The original list of N numbers printed in reverse order of how they appear in the input file. (3) The sum and average of these numbers, (4) The minimum of all the numbers, (5) The maximum of all the numbers.
How can I Cache the data I'm reading from a collection of text files in a directory using a TreeMap? Currently my program reads the data from several text files in a directory and the saves that information in a text file called output.txt. I would like to cache this data in order to use it later. How can I do this using the TreeMap Class? These are the keys,values: TreeMap The data I'd like to Cache is (date from the file, time of the file, current time).
import java.io.*; public class CacheData { public static void main(String[] args) throws IOException { String target_dir = "C:Files"; String output = "C:Filesoutput.txt"; File dir = new File(target_dir); File[] files = dir.listFiles();
Currently working on a simple file processing problem, namely, reorder a set of strings (called bid phrases) in terms of the score value associated to them in descending order.
I have to write a program for sorting an array of random numbers by the users choice. These random numbers are stored in a text file, which the user inputs, and is then stored into an array for sorting. I won't have a problem with the sorting algorithms, but I've never had to read a text file and store it into an array before
The text file has the numbers stored like so : 148 626 817 4 312 652 643 etc....
I gather that I'll probably have to user the Scanner for the user to input the text file name, but how do I store it to an array? So far I only have the bones of the program done, like so
import java.util.Scanner; public class SortingAlgorithms { public static void main(String[] args) {
I am trying to read in lines of text from a file then prints out the text. I only need one 2D array and can't copy from one array to another.This how the file looks like:
4 4 FILE WITH SOME INFO
I have been able to read the file but when I am trying to run my program I have blank spacing instead of an array.
import java.util.Scanner; import java.io.*; public class Array { public static void main(String[] args) throws IOException{
I have a simple txt file, each line simply containing 1 word.I would like each work to represent an index of the array..im having some difficulty populating an array from either a txt file or a scanner.i seem to be able to fill the scanner so to speak with the contents of the text file but not the array. I don't know how to syntax it
import java.io.File; import java.io.FileNotFoundException; import java.util.Scanner; import java.util.Arrays; public class ReadFile public static void main(String[] args) {
I'm trying to figure out the necessary code for reading integers from a text file, then placing them withing the two-dimensional array I have created, and then finally printing the array using a nested for-loop. I have attached the file I would like to read from. I'm having trouble figuring out how to reference the text file with the integers, and also how to properly create a dynamic preface for each row of the array. I want the preface to display as "Week #: ", with # being the row number. I tried to create an integer to be used that way, but NetBeans tells me whatever integer I declare has already been defined in method main. I know I need to use scanner to read the file. I would like the output to display like this:
For example, if I had a text file with one line such as "first, second, third", would there be a way to make it so I could make "first" go to the first array list, "second" to the second, and "third" to the third?
I haven't posted any of my code so far as it wouldn't be right to be handed the finished code on a platter and I should put the work into it, but I'd just need a loop to make it go through the rest of the lines in the text file to add all the first, second and third parts of each line, right?
(I already know how to input data from a file, but not how to split up a line into bits to put into different array lists).
I need to read from a text file given to us that has a list of books with authors names and book titles separated by an @ symbol for our delimiter. Here is the code I have right now, but it throws an ArrayIndexOutOfBoundsException at line 7...and I am unsure why?
import java.io.*; import java.util.*; public class Driver { public static void main(String[] args) { new Driver(args[0]);
[Code] ....
I realize that it must have something to do with my command line argument...but I am unsure what. Am I not entering the file name correctly?
I have an assignment for college that involves placing randomly chosen words from a text file into a 2-d array. I have nearly completed ithowever I am having difficulty with a list of string type.What I have done so far is below,
when I try to run an instance of the program(using BlueJ) I get an error saying there is a null pointer exception at line 35 which is wordsForGrid. add (puzzleWords.get(pos));
I am thinking that this is related to the fact that at this line in the loadWordsFromFile method List <String>words=new ArrayList<String>(); I could not create an empty list of string type, i.e List<String>words = new List<String>();
Is this correct? Or am I looking in the wrong place. The textfile I am using contains over 6000 words on a separate line for each if that makes any difference.
I have an assignment on sorting, i kno i can get the sorting down but im having an issue with inputing the 512 ints in a file into an array. the instructor provided us with a file with 4 equal sets of ints. i tried to make my array of size [scan.nextInt()] and it cuts off the last 21 ints. and skips the first int. how can i get all of the integers in the text file into my array? this is what i have so far. if i hard code the array to size 50000 and then try to print the array it compiles but errors out when running it.
System.out.println("Please Enter text file in this format, XXXXX.txt :"); String file =fileName.nextLine(); Scanner scan = new Scanner(new File(file)); int [] data = new int[scan.nextInt()]; <-------here it skips first int int count= data.length; for (int i=0; i<data.length-1;i++) { data[i]=scan.nextInt(); } System.out.print(Arrays.toString(data));
rst 4 ints in output are: 501, 257, 390, 478...., supposed to be 492,501,390....and last ints are: ....88, 83, 79, 0 and supposed to be :88 83 79 77 76 72 71 71 66 57 56 48 48 41 33 30 23 23 18 17 15 13 9....it replace last ints with 0. why ? and how do i fix this. attached it the text file
