Reading Lines from a String Using a Regular Expression

In this section, you will learn how to separate a string by detecting the line.

Reading Lines from a String Using a Regular Expression

Reading Lines from a String Using a Regular Expression

     

You will learn how to separate a string by detecting the line. An example has been given in the section for the best illustration of the procedure of reading of line from the file.

Program Result:

Following program takes a text file name and reads all the string or text from the file. This program also detects the new line character "\n" and shows all the string or text before occurring the new line character.

Here is the code of the program:

import java.util.regex.*;
import java.io.*;

public class ReadLines{
  public static void main(String[] args)

 
throws IOException,InterruptedException{
  BufferedReader in = new BufferedReader
(
new InputStreamReader(System.in));
  System.out.println("Enter file name: ");
  String filename = in.readLine();
  File file = new File(filename);
  if(!filename.endsWith(".txt")){
  System.out.println("File not in text format.");
  System.exit(0);
  }
  else if(!file.exists()){
  System.out.println("File not found.");
  System.exit(0);
  }

  FileInputStream fstream = new FileInputStream(filename);
  DataInputStream ds = new DataInputStream(fstream);
  BufferedReader br = new BufferedReader(new InputStreamReader(ds));
  Pattern p;
  Matcher m;
  String strLine;
  String inputText = "";
  while((strLine = br.readLine()) != null)

 
inputText = inputText + strLine + "\n";
  String[] paras = Pattern.compile
(
"\n", Pattern.MULTILINE).split(inputText);
  Thread th = new Thread();
  for(int i=0; i<=paras.length-1; i++){
  System.out.println(paras[i]);
  th.sleep(1500);
  }
  }
}

Download this example.