Question

Java code to read from .csv file

i currently have a .csv file that looks like this:

39.743222, -105.006241, Hospital
39.743981, -105.020017, Home
39.739377, -104.984774, Firehouse
39.627779, -104.839291, McDonald's
39.731919, -104.961814, Chipotle

I need to write code to extract the doubles from each line to use for my Linked List.

this is what i have so far:

Scanner in = new Scanner(new FileInputStream(DATA_FILE));

Answer 1

Your code for extracting float values is here; Since you hadn't asked to append to the linked list, I assume you have figured it out.

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.regex.*;

public class CSVReader {

public static void main(String[] args) {
//Enter your full csv destination path
String csvFile = "/Your/csv/file/destination/path/file.csv";
BufferedReader br = null;
String line = "";
String cvsSplitBy = ",";

try {

br = new BufferedReader(new FileReader(csvFile));
while ((line = br.readLine()) != null) {

// use comma as separator
String[] file = line.split(cvsSplitBy);
  
//Regex pattern to extract float values
String regex="([0-9]+[.][0-9]+)";
  
for(int i = 0;i<file.length;i++){
String input= file[i];
Pattern pattern=Pattern.compile(regex);
Matcher matcher=pattern.matcher(input);
while(matcher.find()){
float a = Float.parseFloat(matcher.group());
// Now your float variable 'a' has been extracted; use it to append in your linked list
//Your code here.
}
}

}

} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (br != null) {
try {
br.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}

}

}

Screen shot of the code:

If you face any problem regarding the current code, or if you want help implementing a linked list, please ask in the comments section, I'll be pleased to help.

If you did like my answer, please do give a thumbs up!!!