package com.kaviju.accesscontrol.authentication;

import java.util.Random;

public class RandomPasswordGenerator {
	static final String possibleChars = "23456789abcdefghjklmnpqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ@#$%?&*()-+";
	static final String possibleDigits = "0123456789";
	static Random rnd = new Random();

	static public String newPassword(int len) {
		{
			StringBuilder password = new StringBuilder( len );
			for( int i = 0; i < len; i++ ) {
				int nextCharIndex = rnd.nextInt(possibleChars.length());
				password.append(possibleChars.charAt(nextCharIndex));
			}
			return password.toString();
		}		
	}

	static public String newDigitsPassword(int len) {
		{
			StringBuilder password = new StringBuilder( len );
			for( int i = 0; i < len; i++ ) {
				int nextCharIndex = rnd.nextInt(possibleDigits.length());
				password.append(possibleDigits.charAt(nextCharIndex));
			}
			return password.toString();
		}		
	}
}

package com.kaviju.accesscontrol.authentication;

import java.util.Random;

public class RandomPasswordGenerator {
	static final String possibleChars = "23456789abcdefghjklmnpqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ@#$%?&*()-+";
	static Random rnd = new Random();

	static public String newPassword(int len) {
		{
			StringBuilder password = new StringBuilder( len );
			for( int i = 0; i < len; i++ ) {
				int nextCharIndex = rnd.nextInt(possibleChars.length());
				password.append(possibleChars.charAt(nextCharIndex));
			}
			return password.toString();
		}		
	}
}

--- 
+++ 
@@ -4,6 +4,7 @@
 
 public class RandomPasswordGenerator {
 	static final String possibleChars = "23456789abcdefghjklmnpqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ@#$%?&*()-+";
+	static final String possibleDigits = "0123456789";
 	static Random rnd = new Random();
 
 	static public String newPassword(int len) {
@@ -16,4 +17,15 @@
 			return password.toString();
 		}		
 	}
+
+	static public String newDigitsPassword(int len) {
+		{
+			StringBuilder password = new StringBuilder( len );
+			for( int i = 0; i < len; i++ ) {
+				int nextCharIndex = rnd.nextInt(possibleDigits.length());
+				password.append(possibleDigits.charAt(nextCharIndex));
+			}
+			return password.toString();
+		}		
+	}
 }
Add a digits only password generator.
