package cz.muni.fi.rtc.teacherWorkbench.importer; import java.util.Collection; import java.util.Random; import cz.muni.fi.rtc.teacherWorkbench.importer.exceptions.EmptyPossibleCharsException; import cz.muni.fi.rtc.teacherWorkbench.model.ImportedPerson; /** * Password generator * @author Jan Stastny * */ public class PasswordGenerator { public static final int DEFAULT_LENGTH = 7; private char[] possibleChars = new char[]{'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0'}; private Random seed = new Random(); /** * Creates new password generator. All alpha numeric values are possible for the password */ public PasswordGenerator() { } /** * Generates new password generator. * @param possible Array of chars the password will be generated from */ public PasswordGenerator(char[] possible) { this.possibleChars = possible; } /** * Generates random password of given length * @param length Password length * @return Random password * @throws EmptyPossibleCharsException if the array of possible chars is empty */ public String generatePassword(int length) throws EmptyPossibleCharsException { if(possibleChars.length < 1) { throw new EmptyPossibleCharsException("possibleChars array is empty"); } StringBuffer passwordBuffer = new StringBuffer(); for(int i=0; i < length; i++) { passwordBuffer.append(possibleChars[seed.nextInt(possibleChars.length)]); } return passwordBuffer.toString(); } /** * Generates password of default length. * Default length is taken from DEFAULT_LENGTH constant * @return Random password * @throws EmptyPossibleCharsException if the array of possible chars is empty */ public String generatePassword() throws EmptyPossibleCharsException { return generatePassword(DEFAULT_LENGTH); } /** * Generates passwords for the users. * @param people People to have password generated * @return People with generated passwords */ public static CollectiongeneratePasswordsForPeople(Collection people) { PasswordGenerator generator = new PasswordGenerator(); for(ImportedPerson person: people) { person.setRawPassword(generator.generatePassword()); } return people; } }