/*
 * Copyright 2015 Ryan Gilera.
 *
 * 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 com.github.daytron.revworks.service;

import com.vaadin.server.VaadinRequest;
import com.vaadin.server.VaadinService;
import java.security.Principal;

/**
 *
 * @author Ryan Gilera
 */
public class CurrentUserSession {
    /**
     * The attribute key used to store the username in the session.
     */
    public static final String CURRENT_USER_SESSION_ATTRIBUTE_KEY = 
            CurrentUserSession.class.getCanonicalName();
    
    private CurrentUserSession(){}
    
    /**
     * Sets the name of the current user and stores it in the current session.
     * Using a {@code null} username will remove the username from the session.
     * 
     * @param currentUser The current user
     * @throws IllegalStateException
     *             if the current session cannot be accessed.
     */
    public static void set(Principal currentUser) {
        if (currentUser == null) {
            getCurrentRequest().getWrappedSession().removeAttribute(
                    CURRENT_USER_SESSION_ATTRIBUTE_KEY);
        } else {
            getCurrentRequest().getWrappedSession().setAttribute(
                    CURRENT_USER_SESSION_ATTRIBUTE_KEY, currentUser);
        }
    }
    
    /**
     * Returns the name of the current user stored in the current session, or an
     * empty string if no user name is stored.
     * 
     * @return The user object
     * @throws IllegalStateException
     *             if the current session cannot be accessed.
     */
    public static Principal get() {
        Principal currentUser = (Principal) getCurrentRequest().getWrappedSession()
                .getAttribute(CURRENT_USER_SESSION_ATTRIBUTE_KEY);
        return (currentUser == null) ? null : currentUser;
    }
    
    private static VaadinRequest getCurrentRequest() {
        VaadinRequest request = VaadinService.getCurrentRequest();
        if (request == null) {
            throw new IllegalStateException(
                    "No request bound to current thread");
        }
        return request;
    }
}

/*
 * Copyright 2015 Ryan Gilera.
 *
 * 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 com.github.daytron.revworks.service;

import com.vaadin.server.VaadinRequest;
import com.vaadin.server.VaadinService;
import com.vaadin.server.VaadinSession;
import java.security.Principal;

/**
 *
 * @author Ryan Gilera
 */
public class CurrentUserSession {
    /**
     * The attribute key used to store the username in the session.
     */
    public static final String CURRENT_USER_SESSION_ATTRIBUTE_KEY = 
            CurrentUserSession.class.getCanonicalName();
    
    private CurrentUserSession(){}
    
    /**
     * Sets the name of the current user and stores it in the current session.
     * Using a {@code null} username will remove the username from the session.
     * 
     * @param currentUser The current user
     * @throws IllegalStateException
     *             if the current session cannot be accessed.
     */
    public static void set(Principal currentUser) {
        if (currentUser == null) {
            getCurrentRequest().getWrappedSession().removeAttribute(
                    CURRENT_USER_SESSION_ATTRIBUTE_KEY);
        } else {
            getCurrentRequest().getWrappedSession().setAttribute(
                    CURRENT_USER_SESSION_ATTRIBUTE_KEY, currentUser);
        }
    }
    
    /**
     * Returns the name of the current user stored in the current session, or an
     * empty string if no user name is stored.
     * 
     * @return The user object
     * @throws IllegalStateException
     *             if the current session cannot be accessed.
     */
    public static Principal get() {
        Principal currentUser = (Principal) getCurrentRequest().getWrappedSession()
                .getAttribute(CURRENT_USER_SESSION_ATTRIBUTE_KEY);
        return (currentUser == null) ? null : currentUser;
    }
    
    private static VaadinRequest getCurrentRequest() {
        VaadinRequest request = VaadinService.getCurrentRequest();
        if (request == null) {
            throw new IllegalStateException(
                    "No request bound to current thread");
        }
        return request;
    }
    
    public static void signOut() {
        VaadinSession.getCurrent().getSession().invalidate();
    }
}

Add user signout capability