Java中的缓冲读取器，行数，拆分，解析

Question

Actually, I am assigned a task where I have a xyz.txt/CSV file which will basically have numeric values and I am supposed to pass it through BUFFERED READER then split those values and finally parse them.

So I have a Java code can body help me with it.

package javaapplication12;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.LineNumberReader;

public class JavaApplication12 {   

    public static void main(String[] args) {

        String count= "F:\\Gephi\\number.txt";            
        BufferedReader br = null;
        FileReader fr = null;

        try {           
            fr = new FileReader(count);
            br = new BufferedReader                       

            // AT THIS POINT THERE SHOULD BE SOME THING THAT COUNTS NUMBER OF LINES USING COUNT++ OR SOMETHING LIKE THIS//    
            String sCurrentLine;    
            while ((sCurrentLine = br.readLine()) != null) {
                System.out.println(sCurrentLine);
            }                            
        }             
        catch (IOException e) {
            e.printStackTrace();
        }
        finally {
                try {
                    if (br != null)
                       br.close();

                    if (fr != null)
                       fr.close();
                } 
                catch (IOException ex) {
                    ex.printStackTrace();
                }
        }            
     }
}
                // COMING TO THIS POINT THE ABOVE VALUES OF .TXT FILE SHOULD BE SPLIT USING SPLIT PARAMETER//
               // AFTER SPLITTING THE SPLIT VALUE SHOULD BE KEPT IN AN ARRAY AND THEN EVENTUALLY PARSED//

Or IF Anybody can rewrite the code in another way of the above-stated problem, it shall also be appreciated.

Answer 1

Here is my solution with Java 8:

 import java.io.BufferedReader;
 import java.io.FileReader;
 import java.io.IOException;
 import java.util.List;
 import java.util.stream.Collectors;

 public class BR {

 public static void main(String[] args) {
    String fileName = "br.txt";
    //for the csv format
    String regex = ", ";
    try (BufferedReader br = new BufferedReader(new FileReader(fileName))) {
        List<String[]> lines = br.lines()
                .map(line -> line.split(regex))
                .collect(Collectors.toList());

        parse(lines);
    } catch (IOException e) {
        e.printStackTrace();
    }

}

private static void parse(List<String[]> lines) {
    //Do your stuff here
}

 }

The initialization of the BufferedReader is in the try block (this approach is called try with resources), since BufferedReader implements AutoCloseable (an interface), so in case an exception is thrown the reader will close.

The br.lines() method returns all lines from the file. In the map function you are passing a line that is rad in a lambda. The line is split using the split variable (for CSV format it is ', ') and is returned and collected.

The result is a List of arrays of String which can be changed in the body of the map function.

For more clarification I suggest you check some Java 8 tutorials and you will fully understand what is going on.

This solution might not be appropriate for your knowledge level (I guess), but hope it inspires you to check some fancier and modern approaches.

Have a nice day.