Question

Write a java program. I was given the following case.

Your boss has determined that employee passwords need to be updated and made stronger. The new password policy has the following requirements At least 8 characters in length. Must contain at least one upper case character . Must contain at least one lower case character Must contain one number character Must contain one of the following characters: @,#,%,^,&,* After a couple of weeks, your boss wants to know if all employee passwords now meet the new requirements. He has given you a text file (pwd.txt) and asked you to write a program that will scan the file and create two new files (invalidpwd.txt and validpwd.txt). All invalid passwords from pwd.txt will be written to invalidpwd.txt and all valid passwords from pwd.txt will be written to validpwd.txt.

Answer 1

EmployeePassword.java

// Java Program to illustrate reading from FileReader
// using BufferedReader
import java.io.*;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class EmployeePassword
{
   private Pattern pattern;
   private Matcher matcher;
   //Regular expression for matching with employee password
   private static final String PASSWORD_PATTERN = "((?=.*[a-z])(?=.*\\d)(?=.*[A-Z])(?=.*[@#%^&*]).{8,40})";
   public EmployeePassword() {
pattern = Pattern.compile(PASSWORD_PATTERN);
}
public boolean passwordValidator(String password){
       matcher = pattern.matcher(password);
return matcher.matches();
   }
   public static void main(String[] args)throws Exception
   {
       // We need to provide file path as the parameter:
       // double backquote is to avoid compiler interpret words
       // like \test as \t (ie. as a escape sequence)
       EmployeePassword obj = new EmployeePassword();
       File file = new File("C:\\Users\\ExamCell2k19\\Pictures\\java\\pwd.txt");
       File invalid = new File("C:\\Users\\ExamCell2k19\\Pictures\\java\\invalidpwd.txt");
       File valid = new File("C:\\Users\\ExamCell2k19\\Pictures\\java\\validpwd.txt");
       //FileWriter is used to write into a file
       FileWriter fr1 = new FileWriter(valid);
       FileWriter fr2 = new FileWriter(invalid);
       //BufferedReader for reading the data from the file
       BufferedReader br = new BufferedReader(new FileReader(file));
       String st;
       while ((st = br.readLine()) != null) {
           boolean res = obj.passwordValidator(st);
           if(res){
               fr1.write(st);
               fr1.write("\n");
           }
           else{
               fr2.write(st);
               fr2.write("\n");
           }
       }
       fr1.close();
       fr2.close();
   }
  
}