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Importing a .csv file into java, splitting it to an array or strings

As the title says, I have imported a csv file with 3 columns separated by a comma (,).
When I try to print each column on it's own, the first column prints without problems. When I try the second and third columns (index [1] and [2]), they print as expected but I get an "ArrayIndexOutOfBoundsException" error at the end of the program before exiting. Why is that?
Here is the code below:
public static void main(String[] args) throws IOException {
String path = "C:\\Users\\UserONE\\Downloads\\inSic1.csv";
String line = "";
BufferedReader br = new BufferedReader(new FileReader(path));
while ((line = br.readLine()) != null){
String value [] = line.split(",");
System.out.println(value[1]);

Try printing the values dynamically and not with a hardcoded value.
E.g.
while ((line = br.readLine()) != null)
{
String values[] = line.split(",");
for(String val: values)
{
System.out.println(val);
}
}
This way you will not reach an index that does not exist and you generify the problem, even if you use another file, it will work.

Array index out of bound in java error

package com.testing;
import java.io.BufferedReader;
import java.io.FileReader;
public class CsvParser {
public static void main(String[] args) {
String csvFile = "D:/code-home/SentimentAnalysis/test_data/Sentiment Analysis Dataset.csv";
BufferedReader br = null;
String line = "";
String cvsSplitBy = "\t"; // data is in format splitted by tab
br = new BufferedReader(new FileReader(csvFile));
while ((line = br.readLine()) != null) {
// use comma as separator
String[] tweet = line.split(cvsSplitBy);
System.out.println(tweet[1]);
System.out.println(tweet[3]);
}
}
}
The program's purpose is to parse the CSV format. I have used bufferRead method.
When I go to compile the program, it works fine. When I run the program,output is printed but there is a exception:
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 1
at com.testing.CsvParser.main(CsvParser.java:34)

First of all: Arrays in Java are Zero-indexed, which means that the first element in an array is not selected by array[1] but by array[0]. Since your OutOufBoundsException is fired at the index 1, your array has at most one element in it (you shoulds check for the size of the array before accessing it). Because you are trying to access the index 3 (fourth element in Java) in the very next line i suspect you expect at least 3 elements in each line. Since there is at most one element you seem to either be using the wrong splitcharacter or your file is not formatted as you expect it to be. I hope this helps you. Kind regards

BufferedReader to read lines, then assign the new formed line's tokens to variables

I have a text file that I need to modify before parsing it. 1) I need to combine lines if leading line ends with "\" and delete white spaced line. this has been done using this code
public List<String> OpenFile() throws IOException {
try (BufferedReader br = new BufferedReader(new FileReader(path))) {
String line;
StringBuilder concatenatedLine = new StringBuilder();
List<String> formattedStrings = new ArrayList<>();
while ((line = br.readLine()) != null) {
if (line.isEmpty()) {
line = line.trim();
} else if (line.charAt(line.length() - 1) == '\\') {
line = line.substring(0, line.length() - 1);
concatenatedLine.append(line);
} else {
concatenatedLine.append(line);
formattedStrings.add(concatenatedLine.toString());
concatenatedLine.setLength(0);
}
}
return formattedStrings;
}
}
}//The formattedStrings arrayList contains all of the strings formatted for use.
Now My question, how can I search those lines for pattern and assign their token[i] to variables that I can call or use later.
the New combined text will look like this:
Field-1 Field-2 Field-3 Field-4 Field-5 Field-6 Field-7
Now, if the line contains "Field-6" and "Field-2" Then set the following:
String S =token[1] token[3];
String Y =token[5-7];
Question you might have for me, how am I deciding on which token to save to a string? I will manually search for the pattern in the text file and if the "Line contain Field-6 and Field-2 or any other required pattern. Then manually count which token I need to assign to the string. However, it will be nice if there is another way to approach this, for ex assign what's in between token[4] and token[7] to string (s) if the line has token[2] and token[6]. or another way that provides more Granule Control over what to store as string and what to ignore.

Reading CSV file using BufferedReader resulting in reading alternative lines

I'm trying to read a csv file from my java code. using the following piece of code:
public void readFile() throws IOException {
BufferedReader br = new BufferedReader(new FileReader(fileName));
lines = new ArrayList<String>();
String newLine;
while ((newLine = br.readLine()) != null) {
newLine = br.readLine();
System.out.println(newLine);
lines.add(newLine);
}
br.close();
}
The output I get from the above piece of code is every alternative line [2nd, 4th, 6th lines] is read and returned by the readLine() method. I'm not sure why this behavior exists. Please correct me if I am missing something while reading the csv file.

The first time you're reading the line without processing it in the while loop, then you're reading it again but this time you're processing it. readLine() method reads a line and displaces the reader-pointer to the next line in the file. Hence, every time you use this method, the pointer will be incremented by one pointing to the next line.
This:
while ((newLine = br.readLine()) != null) {
newLine = br.readLine();
System.out.println(newLine);
lines.add(newLine);
}
Should be changed to this:
while ((newLine = br.readLine()) != null) {
System.out.println(newLine);
lines.add(newLine);
}
Hence reading a line and processing it, without reading another line and then processing.

You need to remove the first line in a loop body
newLine = br.readLine();

In java 8, we can easily achieve it
InputStream is = new ByteArrayInputStream(byteArr);
BufferedReader br = new BufferedReader(new InputStreamReader(is));
List<List<String>> dataList = br.lines()
.map(k -> Arrays.asList(k.split(",")))
.collect(Collectors.toCollection(LinkedList::new));
outer list will have rows and inner list will have corresponding column values

split(//s+) dont remove whitespaces

I need to read alot of files and insert the data into Ms sql.
Got a file, it looks the texts are separated by //t.
Split does not do the job, I have even tried with "//s+" as you can see in the code below
public void InsetIntoCustomers(final File _file, final Connection _conn)
{
conn = _conn;
try
{
FileInputStream fs = new FileInputStream(_file);
DataInputStream in = new DataInputStream(fs);
BufferedReader br = new BufferedReader(new InputStreamReader(in));
//String strline contains readline() from BufferedReader
String strline;
while((strline = br.readLine()) != null)
{
if(!strline.contains("#"))
{
String[] test = strline.split("//s+");
if((tempid = sNet.chkSharednet(_conn, test[0] )) != 0)
{
// do something
}
}
}
// close BufferedReader
br.close();
}
I need to know where in my String[] the data is placed in a file with 500k lines. But my Test[] get length 1 and all data from readline are on place 0.
Do I use split wrong ?
Or are there other places I need to look?:
// Mir
haha - Thank you so much - why the hell didnt I see that myself.
yeah ofc. iam using \s+ at all other files.
but thank for pointing it out.

The correct regex is \\s+, with back-shashes instead of forward-slashes.
You could have still tried with \\t