The log file I want to work with is tab-separated and looks like this:
2019-06-06 10:01:02 1.0
2019-06-06 10:25:12 100.0
2019-06-06 11:02:32 2.0
I use the following code to scan through the file:
import java.util.*;
import java.io.*;
public class FirstTry {
public static void main(String[] args)
{
String fileName = "LogFile.csv";
File file = new File(fileName);
try
{
Scanner inputStream = new Scanner(file);
while (inputStream.hasNext()){
String data = inputStream.nextLine();
String[] values = data.split("\\t");
System.out.println(values[0] + " " + values[1]);
}
inputStream.close();
}
catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}
The line
System.out.println(values[0] + " " + values[1]);
prints the following, working output:
2019-06-06 10:01:02
2019-06-06 10:25:12 100.0
2019-06-06 11:02:32
but
System.out.println(values[0] + " " + values[2]);
prints:
2019-06-06 10:01:02 1.0
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException
Why is this exceptions raised vor values[2]
and not values [1]
?
Edit:
Sublime Text Screenshot of the LogFile with the Tabs (5 in total) marked:
Edit 2:
String[] values = data.split("\\t+");
System.out.println(values[0] + " " + values[1]);
prints:
2019-06-06 10:01:02 1.0
2019-06-06 10:25:12 100.0
2019-06-06 11:02:32 2.0
System.out.println(values[0] + " " + values[2]);
results in an java.lang.ArrayIndexOutOfBoundsException
Result of String[] values = data.split("\\t");
1: ["2019-06-06 10:01:02", "", "1.0"]
2: ["2019-06-06 10:25:12", "100.0"]
3: ["2019-06-06 11:02:32 ", "", "2.0"]
Note that double tabulation will split to an empty String.
On line 2 there is a single tabulation which results in an ArrayOutOfBoundsException
because values does not have a third value.
As mentionned by @Thilo, a split on "\\t+"
should fix your problem