Say i have a file called "input.txt" that has a bunch of positive integers in it:
6
5 6 8 6 2 4
and so on....(one integer per line)
I want to read this file and make it into an array. The first integer (in this case 6) tells the number of indexes or elements in the array, so 6 spots. The other numbers fill in the array starting at 0. So at index 0, the number is 5, at index 1 the number is 6, and so on.
Can someone please show me how to read this file and make it into an array called A and return the integers in each index as n?
this is what i have so far:
import java.io.*;
public class inputFile {
public static jobScheduleRecursive(int[] A, int i)
{
try
{
FileReader filereader = new FileReader("input.txt");
BufferedReader bufferedreader = new BufferedReader(filereader);
String line = bufferedreader.readLine();
//While we have read in a valid line
while (line != null) {
//Try to parse integer from the String line
try {
System.out.println(Integer.parseInt(line));
} catch (NumberFormatException nfe) {
System.err.println("Failed to parse integer from line:" + line);
System.err.println(nfe.getMessage());
System.exit(1);
}
开发者_开发技巧 line = bufferedreader.readLine();
}
}
catch(FileNotFoundException filenotfoundexception)
{
System.out.println("File not found.");
}
catch(IOException ioexception)
{
System.out.println("File input error occured!");
ioexception.printStackTrace();
}
return A;
}
Step by step (I will let you fill in the actual code):
- read the first integer (the
java.util.Scanner
can be used to read the next integer) into a variable (let's call itnumberOfInts
) - Create an array called
A
withnumberOfInts
elements - In a loop, counting from
0
tonumberOfInts - 1
(using index variablei
):- read the next integer from the file
- set
A[i]
to be that integer you just read
Here are some references:
http://download.oracle.com/javase/1,5,0/docs/api/java/util/Scanner.html
http://download.oracle.com/javase/tutorial/java/nutsandbolts/arrays.html
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