org.carewebframework.ui.spring.AppContextFinder.java Source code

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Here is the source code for org.carewebframework.ui.spring.AppContextFinder.java

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/**
 * This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. 
 * If a copy of the MPL was not distributed with this file, You can obtain one at 
 * http://mozilla.org/MPL/2.0/.
 * 
 * This Source Code Form is also subject to the terms of the Health-Related Additional
 * Disclaimer of Warranty and Limitation of Liability available at
 * http://www.carewebframework.org/licensing/disclaimer.
 */
package org.carewebframework.ui.spring;

import javax.servlet.http.HttpServletRequest;

import org.carewebframework.api.spring.IAppContextFinder;
import org.carewebframework.api.spring.SpringUtil;
import org.carewebframework.ui.FrameworkWebSupport;

import org.springframework.context.ApplicationContext;
import org.springframework.web.context.ContextLoader;

import org.zkoss.zk.ui.Desktop;

/**
 * Encapsulates the logic for locating the application context within a web environment.
 */
public class AppContextFinder implements IAppContextFinder {

    protected static ApplicationContext rootContext;

    public AppContextFinder() {
        SpringUtil.setAppContextFinder(this);
    }

    /**
     * Creates an application context as a child of the root application context and associates it
     * with the specified desktop. In this way, any objects managed by the root application context
     * are available to the framework context.
     * 
     * @param desktop Desktop for which application context is being created.
     * @return New application context
     */
    public static ApplicationContext createAppContext(final Desktop desktop) {
        final HttpServletRequest httpRequest = FrameworkWebSupport.getHttpServletRequest();
        final String qs = httpRequest.getQueryString();
        final FrameworkAppContext appContext = new FrameworkAppContext(desktop);
        appContext.refresh();
        FrameworkWebSupport.setRequestParams(qs);
        FrameworkWebSupport.setRequestUrl(desktop.getRequestPath());
        return appContext;
    }

    /**
     * Destroys the application context for the current desktop.
     */
    public static void destroyAppContext() {
        destroyAppContext(FrameworkWebSupport.getDesktop());
    }

    /**
     * Destroys the application context associated with the specified desktop.
     * 
     * @param desktop Desktop instance
     */
    public static void destroyAppContext(final Desktop desktop) {
        final FrameworkAppContext appContext = FrameworkAppContext.getAppContext(desktop);

        if (appContext != null) {
            appContext.close();
        }
    }

    /**
     * Returns the application context for the current scope. If no desktop exists or no application
     * context is associated with the desktop, looks for an application context registered to the
     * current thread. Failing that, returns the root application context.
     * 
     * @see org.carewebframework.api.spring.IAppContextFinder#getAppContext()
     * @return An application context.
     */
    @Override
    public ApplicationContext getAppContext() {
        ApplicationContext appContext = FrameworkAppContext.getAppContext(FrameworkWebSupport.getDesktop());
        return appContext == null ? getRootAppContext() : appContext;
    }

    /**
     * Returns the root application context.
     * 
     * @see org.carewebframework.api.spring.IAppContextFinder#getRootAppContext()
     * @return The root application context.
     */
    @Override
    public ApplicationContext getRootAppContext() {
        return rootContext != null ? rootContext : ContextLoader.getCurrentWebApplicationContext();
    }
}