UserGenericPrincipal.java

package com.occamlab.te.realm;

import java.security.Principal;
import java.util.HashMap;
import java.util.logging.Logger;

public class UserGenericPrincipal {

	private static final Logger logger = Logger.getLogger(UserGenericPrincipal.class.getPackage().getName());

	private HashMap<String, Principal> principals = new HashMap<String, Principal>();

	private static volatile UserGenericPrincipal userPrincipal = null;

	public static UserGenericPrincipal getInstance() {

		if (null == userPrincipal) {
			synchronized (UserGenericPrincipal.class) {
				// check again, because the thread might have been preempted
				// just after the outer if was processed but before the
				// synchronized statement was executed
				if (userPrincipal == null) {
					userPrincipal = new UserGenericPrincipal();
				}
			}
		}
		return userPrincipal;
	}

	public Principal removePrincipal(String username) {

		synchronized (principals) {
			return (Principal) principals.remove(username);
		}

	}

	public HashMap<String, Principal> getPrincipals() {
		return principals;
	}

}