de.schlichtherle.license.Policy Maven / Gradle / Ivy
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/*
* Copyright (C) 2005-2015 Schlichtherle IT Services.
* All rights reserved. Use is subject to license terms.
*/
package de.schlichtherle.license;
/**
* Provides an interface for security policies and implements the default
* policy.
*
* @author Christian Schlichtherle
* @version $Id$
*/
// TODO: This should be an interface which's implementation is provided by a
// factory.
public class Policy {
/** The current policy. */
private static Policy current;
//
// Static methods.
//
/**
* Sets the current policy.
*
* @param current The new current policy.
* May be {@code null} to cause the default policy implemented by
* this class to be installed and returned by {@link #getCurrent()}.
*/
public static void setCurrent(Policy current) {
Policy.current = current;
}
/**
* Returns the current policy.
*
* If no current policy has been set, the default policy implemented by
* this class is installed as the current policy and returned.
*/
public static Policy getCurrent() {
if (current == null)
current = new Policy();
return current;
}
//
// Constructors and instance methods.
//
/** Only subclasses can instantiate this class. */
protected Policy() { }
/**
* Checks the given password for compliance to the current password policy.
*
* The default policy implemented by this class ensures that the
* password is at least six characters long and consists of letters and
* digits.
*
* @throws IllegalPasswordException If the given password does not comply
* to the current policy.
*/
public void checkPwd(String pwd) {
final int l = pwd.length(); // may throw NullPointerException
if (l < 6)
throw new IllegalPasswordException();
boolean hasLetter = false, hasDigit = false;
for (int i = 0; i < l; i++) {
final char c = pwd.charAt(i);
if (Character.isLetter(c))
hasLetter = true;
else if (Character.isDigit(c))
hasDigit = true;
}
if (!hasLetter || !hasDigit)
throw new IllegalPasswordException();
}
}