/*
 * Copyright 2002-2018 the original author or authors.
 *
 * 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
 *
 *      https://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.springframework.web.context.support;

import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;

import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.context.support.AbstractRefreshableConfigApplicationContext;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.ResourcePatternResolver;
import org.springframework.lang.Nullable;
import org.springframework.ui.context.Theme;
import org.springframework.ui.context.ThemeSource;
import org.springframework.ui.context.support.UiApplicationContextUtils;
import org.springframework.util.Assert;
import org.springframework.web.context.ConfigurableWebApplicationContext;
import org.springframework.web.context.ConfigurableWebEnvironment;
import org.springframework.web.context.ServletConfigAware;
import org.springframework.web.context.ServletContextAware;

AbstractRefreshableApplicationContext subclass which implements the ConfigurableWebApplicationContext interface for web environments. Provides a "configLocations" property, to be populated through the ConfigurableWebApplicationContext interface on web application startup. 
This class is as easy to subclass as AbstractRefreshableApplicationContext: All you need to implements is the loadBeanDefinitions method; see the superclass javadoc for details. Note that implementations are supposed to load bean definitions from the files specified by the locations returned by the getConfigLocations method. 
Interprets resource paths as servlet context resources, i.e. as paths beneath the web application root. Absolute paths, e.g. for files outside the web app root, can be accessed via "file:" URLs, as implemented by DefaultResourceLoader. 
In addition to the special beans detected by AbstractApplicationContext, this class detects a bean of type ThemeSource in the context, under the special bean name "themeSource". 
This is the web context to be subclassed for a different bean definition format. Such a context implementation can be specified as "contextClass" context-param for ContextLoader or as "contextClass" init-param for FrameworkServlet, replacing the default XmlWebApplicationContext. It will then automatically receive the "contextConfigLocation" context-param or init-param, respectively. 
Note that WebApplicationContext implementations are generally supposed to configure themselves based on the configuration received through the ConfigurableWebApplicationContext interface. In contrast, a standalone application context might allow for configuration in custom startup code (for example, GenericApplicationContext). 
Author:
Juergen Hoeller
See Also:
loadBeanDefinitions
ConfigurableWebApplicationContext.setConfigLocations
ThemeSource
XmlWebApplicationContext
Since:
1.1.3/**
 * {@link org.springframework.context.support.AbstractRefreshableApplicationContext}
 * subclass which implements the
 * {@link org.springframework.web.context.ConfigurableWebApplicationContext}
 * interface for web environments. Provides a "configLocations" property,
 * to be populated through the ConfigurableWebApplicationContext interface
 * on web application startup.
 *
 * <p>This class is as easy to subclass as AbstractRefreshableApplicationContext:
 * All you need to implements is the {@link #loadBeanDefinitions} method;
 * see the superclass javadoc for details. Note that implementations are supposed
 * to load bean definitions from the files specified by the locations returned
 * by the {@link #getConfigLocations} method.
 *
 * <p>Interprets resource paths as servlet context resources, i.e. as paths beneath
 * the web application root. Absolute paths, e.g. for files outside the web app root,
 * can be accessed via "file:" URLs, as implemented by
 * {@link org.springframework.core.io.DefaultResourceLoader}.
 *
 * <p>In addition to the special beans detected by
 * {@link org.springframework.context.support.AbstractApplicationContext},
 * this class detects a bean of type {@link org.springframework.ui.context.ThemeSource}
 * in the context, under the special bean name "themeSource".
 *
 * <p><b>This is the web context to be subclassed for a different bean definition format.</b>
 * Such a context implementation can be specified as "contextClass" context-param
 * for {@link org.springframework.web.context.ContextLoader} or as "contextClass"
 * init-param for {@link org.springframework.web.servlet.FrameworkServlet},
 * replacing the default {@link XmlWebApplicationContext}. It will then automatically
 * receive the "contextConfigLocation" context-param or init-param, respectively.
 *
 * <p>Note that WebApplicationContext implementations are generally supposed
 * to configure themselves based on the configuration received through the
 * {@link ConfigurableWebApplicationContext} interface. In contrast, a standalone
 * application context might allow for configuration in custom startup code
 * (for example, {@link org.springframework.context.support.GenericApplicationContext}).
 *
 * @author Juergen Hoeller
 * @since 1.1.3
 * @see #loadBeanDefinitions
 * @see org.springframework.web.context.ConfigurableWebApplicationContext#setConfigLocations
 * @see org.springframework.ui.context.ThemeSource
 * @see XmlWebApplicationContext
 */
public abstract class AbstractRefreshableWebApplicationContext extends AbstractRefreshableConfigApplicationContext
		implements ConfigurableWebApplicationContext, ThemeSource {

	
Servlet context that this context runs in. /** Servlet context that this context runs in. */
	@Nullable
	private ServletContext servletContext;

	
Servlet config that this context runs in, if any. /** Servlet config that this context runs in, if any. */
	@Nullable
	private ServletConfig servletConfig;

	
Namespace of this context, or null if root. /** Namespace of this context, or {@code null} if root. */
	@Nullable
	private String namespace;

	
the ThemeSource for this ApplicationContext. /** the ThemeSource for this ApplicationContext. */
	@Nullable
	private ThemeSource themeSource;


	public AbstractRefreshableWebApplicationContext() {
		setDisplayName("Root WebApplicationContext");
	}


	@Override
	public void setServletContext(@Nullable ServletContext servletContext) {
		this.servletContext = servletContext;
	}

	@Override
	@Nullable
	public ServletContext getServletContext() {
		return this.servletContext;
	}

	@Override
	public void setServletConfig(@Nullable ServletConfig servletConfig) {
		this.servletConfig = servletConfig;
		if (servletConfig != null && this.servletContext == null) {
			setServletContext(servletConfig.getServletContext());
		}
	}

	@Override
	@Nullable
	public ServletConfig getServletConfig() {
		return this.servletConfig;
	}

	@Override
	public void setNamespace(@Nullable String namespace) {
		this.namespace = namespace;
		if (namespace != null) {
			setDisplayName("WebApplicationContext for namespace '" + namespace + "'");
		}
	}

	@Override
	@Nullable
	public String getNamespace() {
		return this.namespace;
	}

	@Override
	public String[] getConfigLocations() {
		return super.getConfigLocations();
	}

	@Override
	public String getApplicationName() {
		return (this.servletContext != null ? this.servletContext.getContextPath() : "");
	}

	
Create and return a new StandardServletEnvironment. Subclasses may override in order to configure the environment or specialize the environment type returned. /**
	 * Create and return a new {@link StandardServletEnvironment}. Subclasses may override
	 * in order to configure the environment or specialize the environment type returned.
	 */
	@Override
	protected ConfigurableEnvironment createEnvironment() {
		return new StandardServletEnvironment();
	}

	
Register request/session scopes, a ServletContextAwareProcessor, etc. /**
	 * Register request/session scopes, a {@link ServletContextAwareProcessor}, etc.
	 */
	@Override
	protected void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {
		beanFactory.addBeanPostProcessor(new ServletContextAwareProcessor(this.servletContext, this.servletConfig));
		beanFactory.ignoreDependencyInterface(ServletContextAware.class);
		beanFactory.ignoreDependencyInterface(ServletConfigAware.class);

		WebApplicationContextUtils.registerWebApplicationScopes(beanFactory, this.servletContext);
		WebApplicationContextUtils.registerEnvironmentBeans(beanFactory, this.servletContext, this.servletConfig);
	}

	
This implementation supports file paths beneath the root of the ServletContext.
See Also:
ServletContextResource/**
	 * This implementation supports file paths beneath the root of the ServletContext.
	 * @see ServletContextResource
	 */
	@Override
	protected Resource getResourceByPath(String path) {
		Assert.state(this.servletContext != null, "No ServletContext available");
		return new ServletContextResource(this.servletContext, path);
	}

	
This implementation supports pattern matching in unexpanded WARs too.
See Also:
ServletContextResourcePatternResolver/**
	 * This implementation supports pattern matching in unexpanded WARs too.
	 * @see ServletContextResourcePatternResolver
	 */
	@Override
	protected ResourcePatternResolver getResourcePatternResolver() {
		return new ServletContextResourcePatternResolver(this);
	}

	
Initialize the theme capability.
/**
	 * Initialize the theme capability.
	 */
	@Override
	protected void onRefresh() {
		this.themeSource = UiApplicationContextUtils.initThemeSource(this);
	}

	
{@inheritDoc}
Replace Servlet-related property sources. /**
	 * {@inheritDoc}
	 * <p>Replace {@code Servlet}-related property sources.
	 */
	@Override
	protected void initPropertySources() {
		ConfigurableEnvironment env = getEnvironment();
		if (env instanceof ConfigurableWebEnvironment) {
			((ConfigurableWebEnvironment) env).initPropertySources(this.servletContext, this.servletConfig);
		}
	}

	@Override
	@Nullable
	public Theme getTheme(String themeName) {
		Assert.state(this.themeSource != null, "No ThemeSource available");
		return this.themeSource.getTheme(themeName);
	}

}