de.fhg.igd.vaadin.util.VaadinUtil.java Source code

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Here is the source code for de.fhg.igd.vaadin.util.VaadinUtil.java

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// This file is part of Vaadin Utils
//
// Copyright (c) 2012 Fraunhofer IGD
//
// MongoMVCC is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// MongoMVCC is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with Vaadin Utils. If not, see <http://www.gnu.org/licenses/>.
package de.fhg.igd.vaadin.util;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpSession;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import com.google.common.base.Throwables;
import com.vaadin.Application;
import com.vaadin.terminal.ExternalResource;
import com.vaadin.terminal.Resource;
import com.vaadin.terminal.gwt.server.WebApplicationContext;
import com.vaadin.ui.Component;

public final class VaadinUtil {

    private static final ThreadLocal<Application> threadLocalApp = new ThreadLocal<Application>();

    /**
     * same as {@link VaadinUtil#closeApplication(Application)} but tries to retrieve 
     * application from ThreadLocal variable, that can be set up by 
     * {@link VaadinUtil#setApplication()} 
     */
    public static void closeApplication() {
        final Application app = getApplicationInstance();
        final HttpSession session = getHttpSession(app);
        app.close();
        session.invalidate();
    }

    /**
     * closes the application and in addition invalidates the HttpSession, 
     * which is crucial for using session scoped spring beans 
     * in conjunction with vaadin applications  
     */
    public static void closeApplication(Application application) {
        final Application app = getApplicationInstance();
        final HttpSession session = getHttpSession(app);
        app.close();
        session.invalidate();
    }

    @SuppressWarnings("unchecked")
    public static <T extends Application> T getApplicationInstance() {
        final Application app = threadLocalApp.get();
        assert app != null;
        return (T) app;
    }

    /**
     * can only be used if the Vaadin Application has been set with {@link VaadinUtil#setApplication()} 
     * during a still running request
     * this does not work outside of the request thread
     * 
     */
    public static HttpSession getHttpSession() {
        return getHttpSession(getApplicationInstance());
    }

    public static HttpSession getHttpSession(Application app) {
        return getWebApplicationContext(app).getHttpSession();
    }

    /**
     * can only be used if the Vaadin Application has been set with {@link VaadinUtil#setApplication()} 
     * during a still running request
     * this does not work outside of the request thread
     * 
     */
    public static ServletContext getServletContext() {
        return getHttpSession(getApplicationInstance()).getServletContext();
    }

    public static ServletContext getServletContext(Application app) {
        return getHttpSession(app).getServletContext();
    }

    /**
     * can only be used if the Vaadin Application has been set with {@link VaadinUtil#setApplication()} 
     * during a still running request
     * this does not work outside of the request thread
     * 
     */
    public static ApplicationContext getSpringApplicationContext() {
        return WebApplicationContextUtils
                .getRequiredWebApplicationContext(getServletContext(getApplicationInstance()));
    }

    public static ApplicationContext getSpringApplicationContext(Application app) {
        return WebApplicationContextUtils.getRequiredWebApplicationContext(getServletContext(app));
    }

    @SuppressWarnings("unchecked")
    public static <BT> BT getSpringBean(Class<?> beanClass) {
        try {
            return (BT) getSpringApplicationContext().getBean(beanClass);
        } catch (final BeansException e) {
            throw Throwables.propagate(e);
        }
    }

    @SuppressWarnings("unchecked")
    public static <BT> BT getSpringBean(String springBeanRef) {
        try {
            return (BT) getSpringApplicationContext().getBean(springBeanRef);
        } catch (final BeansException e) {
            throw Throwables.propagate(e);
        }
    }

    /**
     * same as {@link VaadinUtil#isProductionMode(Application)} but tries to retrieve application from ThreadLocal variable, that can be set up by 
     * {@link VaadinUtil#setApplication()}
     * @param application
     * @return true if the application is currently running in Vaadin Production Mode
     */
    public static boolean isProductionMode() {
        return Boolean.parseBoolean(getServletContext(getApplicationInstance()).getInitParameter("productionMode"));
    }

    /**
     * checks whether the application is currently running in Vaadin Production Mode,
     * this should be the case if the ServletContext has an init Parameter "productionMode" set to "true"
     * @param application
     * @return
     */
    public static boolean isProductionMode(Application application) {
        return Boolean.parseBoolean(getServletContext(application).getInitParameter("productionMode"));
    }

    public static WebApplicationContext getWebApplicationContext() {
        return (WebApplicationContext) getApplicationInstance().getContext();
    }

    public static WebApplicationContext getWebApplicationContext(Application app) {
        return (WebApplicationContext) app.getContext();
    }

    public static String getWidgetsetName() {
        return getApplicationInstance().getProperty("widgetset");
    }

    public static String getWidgetsetPath() {
        // XXX test if this is still working, is this generic enough for different setups?
        return getServletContext().getContextPath() + "/VAADIN/widgetsets/" + getWidgetsetName();
    }

    public static Resource getWidgetsetResource(String path) {
        return new ExternalResource(VaadinUtil.getWidgetsetPath() + path);
    }

    /**
     * convenience method that stores the passed application reference inside a static ThreadLocal reference
     * best used in conjunction with Vaadin Application implementing {@link com.vaadin.terminal.gwt.server.HttpServletRequestListener}
     * @see {@link https://vaadin.com/wiki/-/wiki/Main/ThreadLocal%20Pattern}
     * @param app
     */
    public static void setApplication(Application app) {
        threadLocalApp.set(app);
    }

    /**
     * checks whether the passed in component is attached to an application, this is true exactly if
     * <li>the application is initialized
     * <li>HttpSession is set up
     * <li>the passed in component is an ancestor of the mainWindow of the application
     * 
     * this implies that 
     * @param c
     * @return
     */
    public static boolean isAttached(Component c) {
        return c.getApplication() != null;
    }
}