Java Code Examples for org.springframework.web.context.ConfigurableWebApplicationContext#setParent()

/**
 * Instantiate the WebApplicationContext for this servlet, either a default
 * {@link org.springframework.web.context.support.XmlWebApplicationContext}
 * or a {@link #setContextClass custom context class}, if set.
 * <p>This implementation expects custom contexts to implement the
 * {@link org.springframework.web.context.ConfigurableWebApplicationContext}
 * interface. Can be overridden in subclasses.
 * <p>Do not forget to register this servlet instance as application listener on the
 * created context (for triggering its {@link #onRefresh callback}, and to call
 * {@link org.springframework.context.ConfigurableApplicationContext#refresh()}
 * before returning the context instance.
 * @param parent the parent ApplicationContext to use, or {@code null} if none
 * @return the WebApplicationContext for this servlet
 * @see org.springframework.web.context.support.XmlWebApplicationContext
 */
protected WebApplicationContext createWebApplicationContext(@Nullable ApplicationContext parent) {
	Class<?> contextClass = getContextClass();
	if (!ConfigurableWebApplicationContext.class.isAssignableFrom(contextClass)) {
		throw new ApplicationContextException(
				"Fatal initialization error in servlet with name '" + getServletName() +
				"': custom WebApplicationContext class [" + contextClass.getName() +
				"] is not of type ConfigurableWebApplicationContext");
	}
	ConfigurableWebApplicationContext wac =
			(ConfigurableWebApplicationContext) BeanUtils.instantiateClass(contextClass);

	wac.setEnvironment(getEnvironment());
	wac.setParent(parent);
	String configLocation = getContextConfigLocation();
	if (configLocation != null) {
		wac.setConfigLocation(configLocation);
	}
	configureAndRefreshWebApplicationContext(wac);

	return wac;
}
 

/**
 * Instantiate the WebApplicationContext for this servlet, either a default
 * {@link org.springframework.web.context.support.XmlWebApplicationContext}
 * or a {@link #setContextClass custom context class}, if set.
 * <p>This implementation expects custom contexts to implement the
 * {@link org.springframework.web.context.ConfigurableWebApplicationContext}
 * interface. Can be overridden in subclasses.
 * <p>Do not forget to register this servlet instance as application listener on the
 * created context (for triggering its {@link #onRefresh callback}, and to call
 * {@link org.springframework.context.ConfigurableApplicationContext#refresh()}
 * before returning the context instance.
 * @param parent the parent ApplicationContext to use, or {@code null} if none
 * @return the WebApplicationContext for this servlet
 * @see org.springframework.web.context.support.XmlWebApplicationContext
 */
protected WebApplicationContext createWebApplicationContext(ApplicationContext parent) {
	Class<?> contextClass = getContextClass();
	if (this.logger.isDebugEnabled()) {
		this.logger.debug("Servlet with name '" + getServletName() +
				"' will try to create custom WebApplicationContext context of class '" +
				contextClass.getName() + "'" + ", using parent context [" + parent + "]");
	}
	if (!ConfigurableWebApplicationContext.class.isAssignableFrom(contextClass)) {
		throw new ApplicationContextException(
				"Fatal initialization error in servlet with name '" + getServletName() +
				"': custom WebApplicationContext class [" + contextClass.getName() +
				"] is not of type ConfigurableWebApplicationContext");
	}
	ConfigurableWebApplicationContext wac =
			(ConfigurableWebApplicationContext) BeanUtils.instantiateClass(contextClass);

	wac.setEnvironment(getEnvironment());
	wac.setParent(parent);
	wac.setConfigLocation(getContextConfigLocation());

	configureAndRefreshWebApplicationContext(wac);

	return wac;
}
 

/**
 * Instantiate the WebApplicationContext for this servlet, either a default
 * {@link org.springframework.web.context.support.XmlWebApplicationContext}
 * or a {@link #setContextClass custom context class}, if set.
 * <p>This implementation expects custom contexts to implement the
 * {@link org.springframework.web.context.ConfigurableWebApplicationContext}
 * interface. Can be overridden in subclasses.
 * <p>Do not forget to register this servlet instance as application listener on the
 * created context (for triggering its {@link #onRefresh callback}, and to call
 * {@link org.springframework.context.ConfigurableApplicationContext#refresh()}
 * before returning the context instance.
 * @param parent the parent ApplicationContext to use, or {@code null} if none
 * @return the WebApplicationContext for this servlet
 * @see org.springframework.web.context.support.XmlWebApplicationContext
 */
protected WebApplicationContext createWebApplicationContext(ApplicationContext parent) {
	Class<?> contextClass = getContextClass();
	if (this.logger.isDebugEnabled()) {
		this.logger.debug("Servlet with name '" + getServletName() +
				"' will try to create custom WebApplicationContext context of class '" +
				contextClass.getName() + "'" + ", using parent context [" + parent + "]");
	}
	if (!ConfigurableWebApplicationContext.class.isAssignableFrom(contextClass)) {
		throw new ApplicationContextException(
				"Fatal initialization error in servlet with name '" + getServletName() +
				"': custom WebApplicationContext class [" + contextClass.getName() +
				"] is not of type ConfigurableWebApplicationContext");
	}
	ConfigurableWebApplicationContext wac =
			(ConfigurableWebApplicationContext) BeanUtils.instantiateClass(contextClass);

	wac.setEnvironment(getEnvironment());
	wac.setParent(parent);
	wac.setConfigLocation(getContextConfigLocation());

	configureAndRefreshWebApplicationContext(wac);

	return wac;
}
 

protected WebApplicationContext createWebApplicationContext(ApplicationContext parent) {
    Class<?> contextClass = getContextClass();
    if (this.logger.isDebugEnabled()) {
        this.logger.debug("Servlet with name '" + getServletName() +
                "' will try to create custom WebApplicationContext context of class '" +
                contextClass.getName() + "'" + ", using parent context [" + parent + "]");
    }
    if (!ConfigurableWebApplicationContext.class.isAssignableFrom(contextClass)) {
        throw new ApplicationContextException(
                "Fatal initialization error in servlet with name '" + getServletName() +
                "': custom WebApplicationContext class [" + contextClass.getName() +
                "] is not of type ConfigurableWebApplicationContext");
    }
    ConfigurableWebApplicationContext wac =
            (ConfigurableWebApplicationContext) BeanUtils.instantiateClass(contextClass);
    
    wac.setParent(parent);
    if (wac.getParent() == null) {
        ApplicationContext rootContext = (ApplicationContext) getServletContext().getAttribute("JetStreamRoot");
        wac.setParent(rootContext);
    }
    wac.setConfigLocation(getContextConfigLocation());
    configureAndRefreshWebApplicationContext(wac);
    return wac;
}
 

/**
 * Instantiate the WebApplicationContext for this servlet, either a default
 * {@link org.springframework.web.context.support.XmlWebApplicationContext}
 * or a {@link #setContextClass custom context class}, if set.
 * <p>This implementation expects custom contexts to implement the
 * {@link org.springframework.web.context.ConfigurableWebApplicationContext}
 * interface. Can be overridden in subclasses.
 * <p>Do not forget to register this servlet instance as application listener on the
 * created context (for triggering its {@link #onRefresh callback}, and to call
 * {@link org.springframework.context.ConfigurableApplicationContext#refresh()}
 * before returning the context instance.
 * @param parent the parent ApplicationContext to use, or {@code null} if none
 * @return the WebApplicationContext for this servlet
 * @see org.springframework.web.context.support.XmlWebApplicationContext
 */
protected WebApplicationContext createWebApplicationContext(@Nullable ApplicationContext parent) {
	// 允许我们自定义容器的类型，通过 contextClass 属性进行配置
	// 但是类型必须要继承 ConfigurableWebApplicationContext，不然将会报错
	Class<?> contextClass = getContextClass();
	if (!ConfigurableWebApplicationContext.class.isAssignableFrom(contextClass)) {
		throw new ApplicationContextException(
				"Fatal initialization error in servlet with name '" + getServletName() +
				"': custom WebApplicationContext class [" + contextClass.getName() +
				"] is not of type ConfigurableWebApplicationContext");
	}
	// 通过反射来创建 contextClass
	ConfigurableWebApplicationContext wac =
			(ConfigurableWebApplicationContext) BeanUtils.instantiateClass(contextClass);

	wac.setEnvironment(getEnvironment());
	wac.setParent(parent);
	// 获取 contextConfigLocation 属性，配置在 servlet 初始化函数中
	String configLocation = getContextConfigLocation();
	if (configLocation != null) {
		wac.setConfigLocation(configLocation);
	}
	// 初始化 Spring 环境包括加载配置环境
	configureAndRefreshWebApplicationContext(wac);

	return wac;
}
 

@Override
@Nonnull
protected WebApplicationContext createWebApplicationContext(@Nullable ApplicationContext parent) {
    if (this.logger.isDebugEnabled()) {
        this.logger.debug(
                String.format("Servlet with name '%s' will try to create custom WebApplicationContext context of class '%s', using parent context [%s]",
                        getServletName(), CubaXmlWebApplicationContext.class.getName(), parent));
    }
    ConfigurableWebApplicationContext wac = new CubaXmlWebApplicationContext() {
        @Override
        protected ResourcePatternResolver getResourcePatternResolver() {
            return new SingleAppResourcePatternResolver(this, libFolder);
        }
    };

    String contextConfigLocation = getContextConfigLocation();
    if (contextConfigLocation == null) {
        throw new RuntimeException("Unable to determine context config location");
    }

    wac.setEnvironment(getEnvironment());
    wac.setParent(parent);
    wac.setConfigLocation(contextConfigLocation);

    configureAndRefreshWebApplicationContext(wac);

    return wac;
}
 

/**
 * Initialize and publish the WebApplicationContext for this servlet.
 * <p>Delegates to {@link #createWebApplicationContext} for actual creation
 * of the context. Can be overridden in subclasses.
 * @return the WebApplicationContext instance
 * @see #FrameworkServlet(WebApplicationContext)
 * @see #setContextClass
 * @see #setContextConfigLocation
 */
protected WebApplicationContext initWebApplicationContext() {
	// 从根容器开始查找
	WebApplicationContext rootContext =
			WebApplicationContextUtils.getWebApplicationContext(getServletContext());
	WebApplicationContext wac = null;

	if (this.webApplicationContext != null) {
		// A context instance was injected at construction time -> use it
		// 有可能在 Spring 加载 bean 时，DispatcherServlet 作为 bean 加载进来了
		// 直接使用在构造函数被注入的 context 实例
		wac = this.webApplicationContext;
		if (wac instanceof ConfigurableWebApplicationContext) {
			ConfigurableWebApplicationContext cwac = (ConfigurableWebApplicationContext) wac;
			if (!cwac.isActive()) {
				// The context has not yet been refreshed -> provide services such as
				// setting the parent context, setting the application context id, etc
				if (cwac.getParent() == null) {
					// The context instance was injected without an explicit parent -> set
					// the root application context (if any; may be null) as the parent
					cwac.setParent(rootContext);
				}
				// 刷新上下文环境
				configureAndRefreshWebApplicationContext(cwac);
			}
		}
	}
	if (wac == null) {
		// No context instance was injected at construction time -> see if one
		// has been registered in the servlet context. If one exists, it is assumed
		// that the parent context (if any) has already been set and that the
		// user has performed any initialization such as setting the context id
		// 根据 contextAttribute 属性加载 WebApplicationContext
		wac = findWebApplicationContext();
	}
	if (wac == null) {
		// No context instance is defined for this servlet -> create a local one
		// 经过上面步骤都没找到，那就来创建一个
		wac = createWebApplicationContext(rootContext);
	}

	if (!this.refreshEventReceived) {
		// Either the context is not a ConfigurableApplicationContext with refresh
		// support or the context injected at construction time had already been
		// refreshed -> trigger initial onRefresh manually here.
		synchronized (this.onRefreshMonitor) {
			// 刷新，初始化很多策略方法
			onRefresh(wac);
		}
	}

	if (this.publishContext) {
		// Publish the context as a servlet context attribute.
		String attrName = getServletContextAttributeName();
		getServletContext().setAttribute(attrName, wac);
	}

	return wac;
}
 

/**
 * Initialize and publish the WebApplicationContext for this servlet.
 * <p>Delegates to {@link #createWebApplicationContext} for actual creation
 * of the context. Can be overridden in subclasses.
 * @return the WebApplicationContext instance
 * @see #FrameworkServlet(WebApplicationContext)
 * @see #setContextClass
 * @see #setContextConfigLocation
 */
protected WebApplicationContext initWebApplicationContext() {
	WebApplicationContext rootContext =
			WebApplicationContextUtils.getWebApplicationContext(getServletContext());
	WebApplicationContext wac = null;

	if (this.webApplicationContext != null) {
		// A context instance was injected at construction time -> use it
		wac = this.webApplicationContext;
		if (wac instanceof ConfigurableWebApplicationContext) {
			ConfigurableWebApplicationContext cwac = (ConfigurableWebApplicationContext) wac;
			if (!cwac.isActive()) {
				// The context has not yet been refreshed -> provide services such as
				// setting the parent context, setting the application context id, etc
				if (cwac.getParent() == null) {
					// The context instance was injected without an explicit parent -> set
					// the root application context (if any; may be null) as the parent
					cwac.setParent(rootContext);
				}
				configureAndRefreshWebApplicationContext(cwac);
			}
		}
	}
	if (wac == null) {
		// No context instance was injected at construction time -> see if one
		// has been registered in the servlet context. If one exists, it is assumed
		// that the parent context (if any) has already been set and that the
		// user has performed any initialization such as setting the context id
		wac = findWebApplicationContext();
	}
	if (wac == null) {
		// No context instance is defined for this servlet -> create a local one
		wac = createWebApplicationContext(rootContext);
	}

	if (!this.refreshEventReceived) {
		// Either the context is not a ConfigurableApplicationContext with refresh
		// support or the context injected at construction time had already been
		// refreshed -> trigger initial onRefresh manually here.
		synchronized (this.onRefreshMonitor) {
			onRefresh(wac);
		}
	}

	if (this.publishContext) {
		// Publish the context as a servlet context attribute.
		String attrName = getServletContextAttributeName();
		getServletContext().setAttribute(attrName, wac);
	}

	return wac;
}
 

/**
 * Initialize and publish the WebApplicationContext for this servlet.
 * <p>Delegates to {@link #createWebApplicationContext} for actual creation
 * of the context. Can be overridden in subclasses.
 * @return the WebApplicationContext instance
 * @see #FrameworkServlet(WebApplicationContext)
 * @see #setContextClass
 * @see #setContextConfigLocation
 */
protected WebApplicationContext initWebApplicationContext() {
	WebApplicationContext rootContext =
			WebApplicationContextUtils.getWebApplicationContext(getServletContext());
	WebApplicationContext wac = null;

	if (this.webApplicationContext != null) {
		// A context instance was injected at construction time -> use it
		wac = this.webApplicationContext;
		if (wac instanceof ConfigurableWebApplicationContext) {
			ConfigurableWebApplicationContext cwac = (ConfigurableWebApplicationContext) wac;
			if (!cwac.isActive()) {
				// The context has not yet been refreshed -> provide services such as
				// setting the parent context, setting the application context id, etc
				if (cwac.getParent() == null) {
					// The context instance was injected without an explicit parent -> set
					// the root application context (if any; may be null) as the parent
					cwac.setParent(rootContext);
				}
				configureAndRefreshWebApplicationContext(cwac);
			}
		}
	}
	if (wac == null) {
		// No context instance was injected at construction time -> see if one
		// has been registered in the servlet context. If one exists, it is assumed
		// that the parent context (if any) has already been set and that the
		// user has performed any initialization such as setting the context id
		wac = findWebApplicationContext();
	}
	if (wac == null) {
		// No context instance is defined for this servlet -> create a local one
		wac = createWebApplicationContext(rootContext);
	}

	if (!this.refreshEventReceived) {
		// Either the context is not a ConfigurableApplicationContext with refresh
		// support or the context injected at construction time had already been
		// refreshed -> trigger initial onRefresh manually here.
		onRefresh(wac);
	}

	if (this.publishContext) {
		// Publish the context as a servlet context attribute.
		String attrName = getServletContextAttributeName();
		getServletContext().setAttribute(attrName, wac);
		if (this.logger.isDebugEnabled()) {
			this.logger.debug("Published WebApplicationContext of servlet '" + getServletName() +
					"' as ServletContext attribute with name [" + attrName + "]");
		}
	}

	return wac;
}
 

/**
 * Initialize and publish the WebApplicationContext for this servlet.
 * <p>Delegates to {@link #createWebApplicationContext} for actual creation
 * of the context. Can be overridden in subclasses.
 * @return the WebApplicationContext instance
 * @see #FrameworkServlet(WebApplicationContext)
 * @see #setContextClass
 * @see #setContextConfigLocation
 */
protected WebApplicationContext initWebApplicationContext() {
	WebApplicationContext rootContext =
			WebApplicationContextUtils.getWebApplicationContext(getServletContext());
	WebApplicationContext wac = null;

	if (this.webApplicationContext != null) {
		// A context instance was injected at construction time -> use it
		wac = this.webApplicationContext;
		if (wac instanceof ConfigurableWebApplicationContext) {
			ConfigurableWebApplicationContext cwac = (ConfigurableWebApplicationContext) wac;
			if (!cwac.isActive()) {
				// The context has not yet been refreshed -> provide services such as
				// setting the parent context, setting the application context id, etc
				if (cwac.getParent() == null) {
					// The context instance was injected without an explicit parent -> set
					// the root application context (if any; may be null) as the parent
					cwac.setParent(rootContext);
				}
				configureAndRefreshWebApplicationContext(cwac);
			}
		}
	}
	if (wac == null) {
		// No context instance was injected at construction time -> see if one
		// has been registered in the servlet context. If one exists, it is assumed
		// that the parent context (if any) has already been set and that the
		// user has performed any initialization such as setting the context id
		wac = findWebApplicationContext();
	}
	if (wac == null) {
		// No context instance is defined for this servlet -> create a local one
		wac = createWebApplicationContext(rootContext);
	}

	if (!this.refreshEventReceived) {
		// Either the context is not a ConfigurableApplicationContext with refresh
		// support or the context injected at construction time had already been
		// refreshed -> trigger initial onRefresh manually here.
		onRefresh(wac);
	}

	if (this.publishContext) {
		// Publish the context as a servlet context attribute.
		String attrName = getServletContextAttributeName();
		getServletContext().setAttribute(attrName, wac);
		if (this.logger.isDebugEnabled()) {
			this.logger.debug("Published WebApplicationContext of servlet '" + getServletName() +
					"' as ServletContext attribute with name [" + attrName + "]");
		}
	}

	return wac;
}