Generating a random alphanumeric string
Hello, can anyone show me an example or give me a clue about how to generate a random alphanumeric string of lets say 16-32 chars? TomCat is obviously doing it for the session ids, but how would I do the same in a servlet? Regards, Christopher Cato - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, email: [EMAIL PROTECTED]
ODP: Generating a random alphanumeric string
see tomcat sources, org.apache.tomcat.util.SessionIdGenerator namely vVolf -Oryginalna wiadomooe- Od: Cato, Christopher [mailto:[EMAIL PROTECTED]] Wysano: 1 marca 2001 15:05 Do: '[EMAIL PROTECTED]' Temat: Generating a random alphanumeric string Hello, can anyone show me an example or give me a clue about how to generate a random alphanumeric string of lets say 16-32 chars? TomCat is obviously doing it for the session ids, but how would I do the same in a servlet? Regards, Christopher Cato - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, email: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, email: [EMAIL PROTECTED]
RE: Generating a random alphanumeric string
Cato,
Here is code that I tried out for generating a user id using the user name
I have to pass a string and it returns a 8 digit alpha numeric
Hope it helps,
Anil
public static String getCode(String text){
String code = "";
text = text.trim();
if(text.length()1){
return null;
}
text = text.toUpperCase();
if(random==null){
random = new java.util.Random();
}
String code_temp = "";
int no_of_chars = 3 ; //not of chars from text
for(int i=0;ino_of_chars;i++){
code_temp =
String.valueOf(text.charAt(random.nextInt(text.length(;
if(code_temp.equals(" ")){
i--;
}else{
code = code + code_temp;
}
}
code = code + java.lang.String.valueOf(random.nextInt(1));
java.util.Date date = new java.util.Date();
code = code + java.lang.String.valueOf(date.getDate());
}catch(Exception e){
return null;
}
return code;
}
-
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RE: Generating a random alphanumeric string
This seems ok for the job. There should be some speedups if you need them.
Cheers
// --- cut ---
public class GenID {
private static String validChars =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
private int _IDlength;
public GenID(int IDlength) {
_IDlength = IDlength;
}
public String generate() {
String resultID = "";
int maxIndex = validChars.length();
java.util.Random rnd = new java.util.Random();
for ( int i = 0 ; i _IDlength ; i++ ) {
int rndPos = Math.abs(rnd.nextInt() % maxIndex);
resultID += validChars.charAt(rndPos);
}
return resultID;
}
}
// --- cut ---
-Original Message-
From: Cato, Christopher [mailto:[EMAIL PROTECTED]]
Sent: Thursday, March 01, 2001 2:05 PM
To: '[EMAIL PROTECTED]'
Subject: Generating a random alphanumeric string
Hello, can anyone show me an example or give me a clue about how
to generate a random alphanumeric string of lets say 16-32 chars?
TomCat is obviously doing it for the session ids, but how would I
do the same in a servlet?
Regards,
Christopher Cato
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, email: [EMAIL PROTECTED]
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, email: [EMAIL PROTECTED]
RE: Generating a random alphanumeric string
i did this a few weeks ago; the code is far from "clean'n'nice", but it does
what it's supposed to, here goes:
Random pwdGen = new Random( System.currentTimeMillis() );
Character temp = new Character( 'a' );
StringBuffer pwd = new StringBuffer();
Vector charPwd = new Vector();
int i = 0;
//0-9
for ( i = 48; 57 = i; i++ )
{
temp = new Character( ( char ) i );
charPwd.addElement( temp );
}
//a-z A-Z
for ( i = 65; 90 = i; i++ )
{
temp = new Character( ( char ) i );
charPwd.addElement( temp );
}
for ( i = 97; 122 = i; i++ )
{
temp = new Character( ( char ) i );
charPwd.addElement( temp );
}
//where i == length of alphanumeric string.
for ( i = 0; 10 i; i++ )
{
pwd.append( ( Character ) charPwd.elementAt( ( int ) ( charPwd.size() *
pwdGen.nextFloat() ) ) );
}
//adrian.
-Original Message-
From: Cato, Christopher [mailto:[EMAIL PROTECTED]]
Sent: 01 March 2001 15:05
To: '[EMAIL PROTECTED]'
Subject: Generating a random alphanumeric string
Hello, can anyone show me an example or give me a clue about how
to generate a random alphanumeric string of lets say 16-32 chars?
TomCat is obviously doing it for the session ids, but how would I
do the same in a servlet?
Regards,
Christopher Cato
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, email: [EMAIL PROTECTED]
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, email: [EMAIL PROTECTED]
RE: Generating a random alphanumeric string
This intrigued me so I just wrote this little program. Of course it could
be wrapped up in a bean and it needs to check against a list of established
passwords but it gives you upper-lower case random sequence of alpha-numeric
characters. Just feed it the length that you want. It even cleans up after
itself. :0)
public class CraigsRandomizer {
// generates a random alpha-numeric sequence
public static void main(String[] args) {
CraigsRandomizer t = new CraigsRandomizer();
t.randomPass(12); // set to length of 12
}
final void randomPass(int len) {
int[] random = new int[len];
int i = 0;
String result = "";
while(i random.length){
int n = (int)(Math.random() * 122);
if (!(n 49) (!((n = 58) (n = 64))) (!((n = 91)
(n =
96 {
random[i] = n;
i++;
}
}
for(int j = 0; j random.length; j++) {
result += (char)random[j];
}
random = null;
System.out.println(result);
}
}
Let me know if I can help.
Regards,
Craig O'Brien
Java Programmer/Web Developer
-Oryginalna wiadomooe-
Od: Cato, Christopher [mailto:[EMAIL PROTECTED]]
Wysano: 1 marca 2001 15:05
Do: '[EMAIL PROTECTED]'
Temat: Generating a random alphanumeric string
Hello, can anyone show me an example or give me a clue about how
to generate a random alphanumeric string of lets say 16-32 chars?
TomCat is obviously doing it for the session ids, but how would I
do the same in a servlet?
Regards,
Christopher Cato
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, email: [EMAIL PROTECTED]
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, email: [EMAIL PROTECTED]
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, email: [EMAIL PROTECTED]
