# CurrentUserSubject.java

    /*
     * Copyright (c) 2011, Rickard Öberg. All Rights Reserved.
     *
     * Licensed under the Apache License, Version 2.0 (the "License");
     * you may not use this file except in compliance with the License.
     * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS,
     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     * See the License for the specific language governing permissions and
     * limitations under the License.
     *
     */

    package org.qi4j.library.eventsourcing.domain.factory;

    import java.security.AccessController;
    import javax.security.auth.Subject;
    import org.qi4j.library.eventsourcing.domain.spi.CurrentUser;

    /**
     * Uses thread-associated Subject to get the current user name. Default to "unknown".
     */
    public class CurrentUserSubject
        implements CurrentUser
    {
        @Override
        public String getCurrentUser()
        {
            try
            {
                return Subject.getSubject( AccessController.getContext() ).getPrincipals().iterator().next().getName();
            } catch (Exception e)
            {
                return "unknown";
            }
        }
    }