org.carewebframework.api.spring.SpringUtil.java Source code

Introduction

Here is the source code for org.carewebframework.api.spring.SpringUtil.java

Source

/**
 * 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.api.spring;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
import org.springframework.core.env.PropertySource;

/**
 * Static utility class for the access to Spring Framework services.
 */
public class SpringUtil {

    private static IAppContextFinder appContextFinder;

    /**
     * Sets the finder logic for locating the framework context. This is set during framework
     * initialization and should not be changed.
     * 
     * @param appContextFinder The application context finder.
     */
    public static void setAppContextFinder(IAppContextFinder appContextFinder) {
        SpringUtil.appContextFinder = appContextFinder;
    }

    /**
     * Returns the application context (container) associated with the current framework instance.
     * Will return null if an application context cannot be inferred or has not yet been created.
     * 
     * @return Application context
     */
    public static ApplicationContext getAppContext() {
        return appContextFinder == null ? null : appContextFinder.getAppContext();
    }

    /**
     * Returns the root application context (container) associated with the application. Will return
     * null if an application context cannot be inferred or has not yet been created.
     * 
     * @return Root application context
     */
    public static ApplicationContext getRootAppContext() {
        return appContextFinder == null ? null : appContextFinder.getRootAppContext();
    }

    /**
     * Returns true if an application context has been loaded.
     * 
     * @return boolean True if an application context has been loaded
     */
    public static boolean isLoaded() {
        return getAppContext() != null;
    }

    /**
     * Returns the bean with an id matching the specified id, or null if none found.
     * 
     * @param id Bean id
     * @return Returns the bean instance whose id matches the specified id, or null if none found or
     *         if the application context cannot be determined.
     */
    public static Object getBean(final String id) {
        final ApplicationContext appContext = getAppContext();
        return appContext == null ? null : appContext.containsBean(id) ? appContext.getBean(id) : null;
    }

    /**
     * Returns the bean with an id matching the specified id, or null if none found.
     * 
     * @param id Bean id
     * @param clazz Expected return type.
     * @return Returns the bean instance whose id matches the specified id, or null if none found or
     *         if the application context cannot be determined.
     */
    public static <T> T getBean(String id, Class<T> clazz) {
        ApplicationContext appContext = getAppContext();
        return appContext == null ? null
                : appContext.containsBean(id) && appContext.isTypeMatch(id, clazz) ? appContext.getBean(id, clazz)
                        : null;
    }

    /**
     * Returns a property value from the application context.
     * 
     * @param name Property name.
     * @return Property value, or null if not found.
     */
    public static String getProperty(String name) {
        ApplicationContext appContext = getRootAppContext();

        if (appContext == null) {
            return null;
        }

        String value = appContext.getEnvironment().getProperty(name);

        if (value == null) {
            PropertySourcesPlaceholderConfigurer cfg = appContext
                    .getBean(PropertySourcesPlaceholderConfigurer.class);
            PropertySource<?> ps = cfg.getAppliedPropertySources()
                    .get(PropertySourcesPlaceholderConfigurer.LOCAL_PROPERTIES_PROPERTY_SOURCE_NAME);
            value = ps == null ? null : (String) ps.getProperty(name);
        }

        return value;
    }

    /**
     * Enforce static class.
     */
    private SpringUtil() {
    };

}