how to read input from a file in java code example

Example: java read text file

// how to read text file line by line using FileReader class
import java.io.FileReader;
import java.io.IOException;
public class JavaReadTextFileUsingFileReader
{
   public static void main(String[] args) throws IOException
   {
      FileReader fr = new FileReader("B:\demo.txt");
      int a;
      while((a = fr.read()) != -1)
      {
         System.out.print((char) a);
      }
      fr.close();
   }
}