Java:-Find particular substring from a .txt file.

Java:-The below mentioned code enables user to find a particular length of a string whenever required from a file(.txt file or something like that).

Example:-I have a requirement to extract 10 digit card number which was written like CardNumber:="'1234567890".

Note:-Put your sample txt file in workspace or modify file reader argument accordingly.

Code:-

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

public class PatternMatch {

 public static void main(String[] args) {
  try {
   BufferedReader br= new BufferedReader(new FileReader("C:\\workspace\\newfile.txt"));
   String line;
   int lastindex=0;
   try {
    while((line=br.readLine())!=null){
    while(lastindex!=-1){
   lastindex = line.indexOf("CardNumber",lastindex);
    if(lastindex!=-1){
    String substr=line.substring(lastindex+14,lastindex+14+10);
     System.out.println(substr);
    lastindex=lastindex+14+10;
     }
     }
    }
   } catch (IOException e) {
    e.printStackTrace();
   }
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  }
 }

}