Java tutorial
/* * 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; /** * {@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. */ @Nullable private ServletContext servletContext; /** Servlet config that this context runs in, if any. */ @Nullable private ServletConfig servletConfig; /** Namespace of this context, or {@code null} if root. */ @Nullable private String namespace; /** 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 {@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 {@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 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 ServletContextResourcePatternResolver */ @Override protected ResourcePatternResolver getResourcePatternResolver() { return new ServletContextResourcePatternResolver(this); } /** * Initialize the theme capability. */ @Override protected void onRefresh() { this.themeSource = UiApplicationContextUtils.initThemeSource(this); } /** * {@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); } }