Line Number Reader Example

Here, providing you an example that reads a file line by line.

Line Number Reader Example

     

In this example we are reading  number of lines.

In this example we are reading a file from system .Then we are reading number of lines in this file. FileReader class provides readLine() method.The  readLine() method is used to read the data line by line. LineNumberReader class is provide getLineNumber() method to get the number of line. We are using File(String file_name) constructor to make an object of file. We are reading file by use of FileReader(File file) constructor. We are using LineNumberReader(FileReader filereader) constructor to create an object of LineNumberReader class.

The methods used in this example:

getLineNumber():
This method is used to get the number of line.

readLine():
This method is used to read the data line by line. Then returns the data of a line as a single string.

The code of the program is given below:

import java.io.*;
public class LineNumberReaderExample{
  public static void main(String[] argsthrows Exception{
  File file = null;
  FileReader freader = null;
  LineNumberReader lnreader = null;
  try{
  file = new File("LineNumberReaderExample.java");
  freader = new FileReader(file);
  lnreader = new LineNumberReader(freader);
  String line = "";
  while ((line = lnreader.readLine()) != null){
  System.out.println("Line:  " + lnreader.
getLineNumber
() ": " + line);
  }
  }
  finally{
  freader.close();
  lnreader.close();
  }
  }
}

The output of the program is given below:

C:\convert\rajesh\completed>javac LineNumberReaderExample.java
C:\convert\rajesh\completed>java LineNumberReaderExample
Line:  1: import java.io.*;
Line:  2: public class LineNumberReaderExample{
Line:  3:       public static void main(String[] args) 
throws Exception{
Line:  4:               File file = null;
Line:  5:               FileReader freader = null;
Line:  6:               LineNumberReader lnreader = null;
Line:  7:               try{
Line:  8:                       file = new File("
LineNumberReaderExample.java");
Line:  9:                       freader = new FileReader(file);
Line:  10:                      lnreader = new 
LineNumberReader(freader);
Line:  11:                      String line = "";
Line:  12:                      while ((line = 
lnreader.readLine()) != null){
Line:  13:                              System.out.
println("Line:  " + lnreader.
getLineNumber() + ": " + line);
Line:  14:                      }
Line:  15:              }
Line:  16:              finally{
Line:  17:                      freader.close();
Line:  18:                      lnreader.close();
Line:  19:              }
Line:  20:      }
Line:  21: }

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