Java method for generating random passwords (random length, specified length)

Java generates a random length password.

The code is as follows:

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/** * Generate a random password * * @ Param pwd_len * Total length of the generated password * @ Return password string */ Public static String genRandomNum (int pwd_len ){ // 35 is because the array starts from 0 and 26 letters + 10 digits Final int maxNum = 36; Int I; // The random number generated Int count = 0; // The length of the generated password Char [] str = {'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', '0 & prime;, '1 & prime;, '2 & prime;, '3 & prime ;, '4 & prime;, '5 & prime;, '6 & prime;, '7 & prime;, '8 & prime;, '9 & prime ;}; StringBuffer pwd = new StringBuffer (""); Random r = new Random (); While (count <pwd_len ){ // Generate a random number and take the absolute value to prevent negative numbers, I = Math. abs (r. nextInt (maxNum); // The maximum number generated is 36-1. If (I> = 0 & I <str. length ){ Pwd. append (str [I]); Count ++; } } Return pwd. toString (); } /** * @ Param args */ Public static void main (String [] args ){ // TODO Auto-generated method stub System. out. println (genRandomNum (14); // Generate a 14-bit random password }

Generate a random password of the specified length

The code is as follows:

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Import java. util. Random; Public class test { /** * @ Param args */ Public static void main (String [] args ){ // TODO Auto-generated method stub System. out. println (genRandomNum (10 ));  } /** * Generate a password immediately * @ Param pwd_len total length of the password generated * @ Return password string */ Public static String genRandomNum (int pwd_len ){ // 35 is because the array starts from 0 and 26 letters + 10 digits Final int maxNum = 36; Int I; // The random number generated Int count = 0; // The length of the generated password Char [] str = {'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', '0', '1', '2', '3', '4', '5', '6 ', '7', '8', '9 '};   StringBuffer pwd = new StringBuffer (""); Random r = new Random (); While (count <pwd_len ){ // Generate a random number and take the absolute value to prevent negative numbers,    I = Math. abs (r. nextInt (maxNum); // The maximum number generated is 36-1.    If (I> = 0 & I <str. length ){ Pwd. append (str [I]); Count ++;    }   }   Return pwd. toString ();  } }

Java generates 15-bit random code

The code is as follows:

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Import java. util. ArrayList; Import java. util. List; Public class GeneratePswd { @ SuppressWarnings ({"unchecked", "unchecked "}) Public static void main (String [] args ){ StringBuffer buf = new StringBuffer ("a, B, c, d, e, f, g, h, I, g, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z "); Buf. append (", A, B, C, D, E, F, G, H, I, G, K, L, M, N, O, P, Q, R, s, T, U, V, W, X, Y, Z "); Buf. append (",~, @, #, $, %, ^, &, *, (,), _, +, | ,',."); Buf. append (", 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 "); String [] arr = buf. toString (). split (","); List pswdList = new ArrayList ();    For (int I = 0; I <50; I ++ ){ PswdList. add (getPswd (arr ));   }    For (int I = 0; I <pswdList. size (); I ++ ){ System. out. println (pswdList. get (I ));   }  }   Public static String getPswd (String [] arr ){ StringBuffer B = new StringBuffer (); Java. util. Random r; Int k; For (int I = 0; I <15; I ++ ){ R = new java. util. Random (); K = r. nextInt (); B. append (String. valueOf (arr [Math. abs (k % 76)]);   }    Return B. toString ();  } }