Java Reading Txt File Into Array
May 5, 2015
I'm currently working on a program what is reading a txt file with a bunch of numbers in it but keep getting an error back.
Validator.java:
import java.io.IOException;
import java.io.File;
import java.util.Scanner;
public class Validator {
public int[] accounts = {};
[Code] ....
Accounts.txt:
5658845
8080152
1005231
4520125
4562555
6545231
7895122
5552012
3852085
8777541
5050552
7576651
8451277
7825877
7881200
1302850
1250255
4581002
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Sep 13, 2014
//compiler error I'm receiving
J:CS3Student Folder Review Lab #2APlusImage.java:41: error: cannot find symbol
xcor.add(read.nexInt());
[Code].....
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Dec 9, 2014
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.....
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Dec 8, 2014
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.....
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Mar 22, 2015
How do I read in a file line by line into an array without using arraylist?
I know how to do this using BufferedReader, but I am wondering how to do this using Scanner? When I used BufferedReader I noticed that there must be two exceptions to be caught which were IOException and FileNotFoundException, whereas a Scanner needs only a FileNotFoundException, why is that?
Java Code: public class practice {
public String[] array;
Scanner inputStream = null;
Scanner n = new Scanner(System.in);
public String line;
[Code].....
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Jun 5, 2014
I can read the data to a monitor perfectly. But, I'm having problem reading data from an external file into an array of class objects. Here's my attempt at writing the method:
private void openFile()
//This method asks the user to enter a file name(including the file extension) and then
//Sets the data to an array of Product type {
String fileName, storeName="", emptyLine1="", emptyLine2="", name="", productName="";
int demandRate=0;
double setupCost=0.0, unitCost=0.0, inventoryCost=0, sellingPrice=0;
Scanner inputStream = null;
[code]...
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Apr 15, 2014
I am reading records from a txt file and storing it into an array
import java.util.*;
import java.io.*;
public class PatientExercise {
//patients exercise time
public static void main (String[]args) throws IOException{
Scanner in = new Scanner(new FileReader("values.txt"));
double [] patientTimeRecords = new double [300];
int noExerciseCount=0, numPatients =0;
double highest=0, lowest=0, avg=0, totalTime=0;
[Code] ....
However an error msg keeps popping up:
Exception in thread "main" java.util.NoSuchElementException
at java.util.Scanner.throwFor(Scanner.java:907)
at java.util.Scanner.next(Scanner.java:1530)
at java.util.Scanner.nextDouble(Scanner.java:2456)
at pastpapers.PatientExercise.main(PatientExercise.ja va:44)
line 44 is:patientTimeRecords[i]= in.nextDouble();
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Oct 17, 2014
I'm trying to read from a file. we made an array of LinkedList and when I'm reading from the file i get a runtime error "index out of bounce in line 66"
import java.lang.*;
import java.util.*;
public class HashTester{
LinkedList_t [] hash;
LinkedList_t [][] doubleHasher;
int size;
[Code] .......
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Oct 21, 2014
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?
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Apr 5, 2014
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
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Sep 22, 2014
Im trying to read a file called m1 and put that information into a 2-D array with the first two numbers being the size of the array i was able to set the size of the array but how do i populate array?
import java.util.Scanner;
import java.io.*;
public class test{
public static void main(String [] args)throws IOException{
Scanner fr = new Scanner(new File("m1.txt"));
String line = fr.nextLine();
[code]....
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Jan 5, 2014
reading a large json file which is really huge and it contains pair of id and URL in a array as shown below.. i need to get this all id and URL from this file in my java code and need to perform operations . how to read such a big file and store the contents in java code to process it further.
{
"Array": [
{
"id": "1test",
"URL": "http://servername/test/1test.html"
},
{
"id": "2test",
"URL": "http://servername/test/2test.html"
}
....................many id and URL in the same Array which makes the file Huge..
]
}
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Oct 7, 2014
I am trying to make a bank program that reads to .txt files, one that has the right format and one that has the wrong format. This is part of my problem I do not know how to do this. I also do not know why my code works if I input "account" rather than "account.txt" which is supposed to be the right thing.
Let me present my code that I have so far:
// File: BankAccount.java
import java.util.Scanner;
import java.io.IOException;
public class BankAccount
{
private int accountNumber;
private double balance;
[Code] ....
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Apr 23, 2015
I am advised to use a while loop the Scanner method hasNextLine() and in the while loop body, call the Scanner method nextLine(), and add the returned String to the ArrayList of Strings. what I have gotten so far:
Scanner input = new Scanner(new File(""));
while(input.hasNextLine()) {
String line = input.nextLine();
System.out.println(line);
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Feb 8, 2014
We have an autosys job running in our production on daily basis. It calls a shell script which in turn calls a java servlet. This servlet reads these files and inserts the data into two different tables and then does some processing. Java version is 1.6 & application server is WAS7 and database is oracel-11g.
We get several issues with this process like it takes time, goes out of memory etc etc. Below are the details of the way we have coded this process.
1. When we read the file using BufferedReader, do we really get a lot of strings created in the memory as returned by readLine() method of BufferedReader? These files contain 4-5Lacs of line. All the records are separated by newline character. Is there a better way to read files in java to achieve efficiency? I couldnt find any provided the fact that all the record lines in the file are of variable length.
2. When we insert the data then we are doing a batch process with statement/prepared statement. We are making one batch containing all the records of the file. Does it really matter to break the batch size to have better performance?
3. If the tables has no indexes defined nor any other constraints and all the columns are VARCHAR type, then which operation will be faster:- inserting a new row or updating an existing row based upon some matching condition?
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Apr 30, 2014
i have I byte array ,That I was getting from the gps packets , I need to convert that into jpg file
public static void writejpegfile(byte[] someByteArray) throws FileNotFoundException, IOException {
FileOutputStream fos = new FileOutputStream("image" + new Date().getTime() + ".jpg")
try {
[Code]....
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Jan 18, 2014
I have a CSV file with 16K entries of a data table. Does Java work well with CSV file? So I found this code. And it seems its quite easy to read in the data I need. Say for example if I wanted a loop to randomly pick the first field of a specific line in the CSV data table. How would i go about coding that??????
package cvs.test;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
[code]....
The CSV looks like the above. and I basically would like to read in the Hand to get it to show in a text box and then randomly have the program ask me to correctly identify the True/False return for one of the SB/BB/UG/MP/CO/BN columns.
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Mar 19, 2015
I was wondering if it's possible to do this: I want to build a java program that reads a java array from a text file.
Then I want to read it, and output it in a different format.
The reading and out is easy - as text.
But how can I incorporate the read text in to a java valid array in my program, which I can use?
Is this even possible?
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Mar 3, 2013
how to get the first few hex symbols of a file in java, for example if i input a pdf into my coding i want my program to output, e.g "25 46 44 38" ....
I have been able to print out the hex of a whole file but not managed to set a maximum read limit so that my code only takes a certain amount of values ....
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Mar 21, 2014
I am implementing a recursive descent parser that recognizes strings in the language below. The input should be from a file "input.txt" and output should be to the console.
The grammar:
A -> I = E | E
E -> T + E | T - E | T
T -> F * T | F / T | F
F -> P ^ F | P
P -> I | L | UI | UL | (A)
U -> + | - | !
I -> C | CI
C -> a | b | ... | y | z
L -> D | DL
D -> 0 | 1 | ... | 8 | 9
An example session might look like this:
String read from file: a=a+b-c*d
The string "a=a+b-c*d" is in the language.
String read from file: a=a**b++c
The string "a=a**b++c" is not in the language.
Java Code: /**
* The Grammar
* A -> I = E | E
*E -> T + E | T - E | T
*T -> F * T | F / T | F
*F -> P ^ F | P
*P -> I | L | UI | UL | (A)
*U -> + | - | !
[code]....
My current output looks like this:
Java Code: The string read from file: a=a+b-c*d
The string "" is not in the language. mh_sh_highlight_all('java');
So it seems to be reading the input file correctly. My error seems to be on this part
Java Code: s = args.length == 1 ? args[0] : ""; mh_sh_highlight_all('java');
When I put the string in that line such as: s = args.length == 1 ? args[0] : "a=a+b-c*d";
My output is:
Java Code: The string read from file: a=a+b-c*d
The string "a=a+b-c*d" is in the language. mh_sh_highlight_all('java');
How can I go about it reading the string from the input file though?
Also, I am not too sure my boolean functions for P, I and, L are correct. Mainly when two terms are together (UI, UL, CI, DL).
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Jan 27, 2013
I am trying to read a content of file downloaded from ftp and return it as a String. This is what I use:
Java Code:
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import org.apache.commons.net.ftp.FTPClient;
public class Test {
public static void main(String [] args) throws IOException{
FTPClient ftp = new FTPClient();
[code]....
The code does not work, although all the links are correct.
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Oct 22, 2014
I have to read from a file that is formatted like that :
name
status
friend
END
name
status
friend
END
.. etc
could be more than one line of friends, which where I have my problem. I can't get it to check if after the friend name the word "END"
I have tried to write a while loop inside the main while loop but it didn't work, and now I have tried to check that in a separate function which it also failed, thats my two while loops
BufferedReader br = null;
FileReader fr = null;
int getLine = 0;
try {
String line;
fr = new FileReader(fileName);
br = new BufferedReader(fr);
[Code] .....
Most of the time I got nullPointerException or missed up order for printing the file !!
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Sep 9, 2014
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.
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Mar 29, 2014
I'm new to Java and have not been able to figure this out. I'm reading a text file that contains this:
110001 commercial 500000.00 101
110223 residential 100000.00 101
110020 commercial 1000000.00 107
110333 land 30000.00 105
110442 farm 200000.00 106
110421 land 40000.00 107
112352 residential 250000.00 110
The output goes to a text file and should look like this:
COMMERICAL
FARM
LAND
RESIDENTIAL
101 600000.00
105 30000.00
106 200000.00
107 1040000.00
110 250000.00
I'm creating the output file, but it only contains the categories and not the details below them. Cant seem to figure out why.
Java Code:
package propertylistings;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;
[Code] ....
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Oct 6, 2014
I am trying to read from a text file that has that contains a list of stock tickers and pairs letting the user choose a ticker and provide analysis of stock. Given a ticker from the user provide
1) the max price, the min price and the avg price of the stock from all lines in the file.
2)Additionally the user should be able to find the stock with the highes price as well as the lowest price in the list.
3)lastly the user should be able to specify a different filename for the stock file.
Im trying to do part 1 and I am having trouble trying to read the whole text file and outputting the stock price with the max,min and avg. Am I heading towards the right track at least? Keep in mind I have just attempted trying to read the text file I have and not tried to find the max or min or avg Right now my code is crashing when I enter the stock ticker that is my primary concern.
package hw01b;
import java.util.Scanner;
import java.io.*;
public class Hw01b
{
static Scanner in = new Scanner(System.in);
static Scanner console = new Scanner(System.in);
[Code] .....
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Feb 20, 2014
Write a program that extracts words from a file. For the purposes of this program, a word is defined as a series of adjacent letters. Only print words that are at least four and no more than 12 letters long. Print each word on a different line.
The program should read the name of the file from the keyboard.
************************************************** ************************************************** **************
I need to get the filename from the user for this particular program. Usually I would have the name of the file prewritten into the source code like this....
Scanner input = new Scanner(new File("gettsy_burg.txt");
I tried different ways but I just can't seem to figure it out.... I guess what I'm really asking is how to rearrange Scanner input = new Scanner(new File("gettsy_burg.txt"); since I want the user to input the filename instead of the filename being prewritten by the programmer(me).
This is what I have so far to let the user for input....
Scanner keys = new Scanner(System.in);
System.out.println("Enter the filename: ");
String fileName = keys.nextLine();
keys = new Scanner(new File(fileName));
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