Spring Cloud实战小贴士:Zuul处理Cookie和重定向
所以解决该问题的思路也很简单,我们只需要通过设置sensitiveHeaders即可,设置方法分为两种:
- 全局设置:
zuul.sensitive-headers=
- 指定路由设置:
zuul.routes.<routeName>.sensitive-headers=
zuul.routes.<routeName>.custom-sensitive-headers=true
重定向问题
在使用Spring Cloud Zuul对接Web网站的时候,处理完了会话控制问题之后。往往我们还会碰到如下图所示的问题,我们在浏览器中通过Zuul发起了登录请求,该请求会被路由到某WebSite服务,该服务在完成了登录处理之后,会进行重定向到某个主页或欢迎页面。此时,仔细的开发者会发现,在登录完成之后,我们浏览器中URL的HOST部分发生的改变,该地址变成了具体WebSite服务的地址了。这就是在这一节,我们将分析和解决的重定向问题!
出现该问题的根源是Spring Cloud Zuul没有正确的处理HTTP请求头信息中的Host导致。在Brixton版本中,Spring Cloud Zuul的PreDecorationFilter
过滤器实现时完全没有考虑这一问题,它更多的定位于REST API的网关。所以如果要在Brixton版本中增加这一特性就相对较为复杂,不过好在Camden版本之后,Spring Cloud Netflix 1.2.x版本的Zuul增强了该功能,我们只需要通过配置属性zuul.add-host-header=true
就能让原本有问题的重定向操作得到正确的处理。关于更多Host头信息的处理,读者可以参考本文之前的分析思路,可以通过查看PreDecorationFilter
过滤器的源码来详细更多实现细节。
http://blog.didispace.com/spring-cloud-zuul-cookie-redirect/
一 介绍
很多场景下,需要在运行期间动态调整配置。如果配置发生了修改,微服务也应该实现配置的刷新。
下面实现配置的手动刷新。
二 新建项目microservice-config-client-refresh
三 为项目添加spring-boot-starter-actuator依赖,该依赖包含了/refresh端点,用于配置的刷新。
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-config</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
</dependencies>
四 在Controller上添加注解@RefreshScope。添加@RefreshScope的类会在配置更改时得到特殊处理。
package com.itmuch.cloud.study.controller;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
@RefreshScope
public class ConfigClientController
@Value("$profile")
private String profile;
@GetMapping("/profile")
public String hello()
return this.profile;
五 测试
1 启动microservice-config-server
2 启动microservice-config-client-refresh
3 访问http://localhost:8081/profile,获得结果
dev-1.0
4 修改Git仓库中microservice-foo-dev.properties的文件内容为:
profile=dev-1.0-change
5 重新访问http://localhost:8081/profile,获得结果依然是:
dev-1.0
6 发送post请求到http://localhost:8081/refresh,结果返回
[
"config.client.version",
"profile"
]
7 再次访问http://localhost:8081/profile,返回结果为:
dev-1.0-change
说明配置已经刷新
---------------------
作者:chengqiuming
来源:CSDN
原文:https://blog.csdn.net/chengqiuming/article/details/80872615
版权声明:本文为博主原创文章,转载请附上博文链接!
https://tech.asimio.net/2017/10/10/Routing-requests-and-dynamically-refreshing-routes-using-Spring-Cloud-Zuul-Server.html
https://www.cnblogs.com/flying607/p/8459397.html
《spring扩展点之三:Spring 的监听事件 ApplicationListener 和 ApplicationEvent 用法,在spring启动后做些事情》
在spring-cloud-netflix-core-1.4.4.RELEASE.jar中org.springframework.cloud.netflix.zuul.RoutesRefreshedEvent.java
@SuppressWarnings("serial") public class RoutesRefreshedEvent extends ApplicationEvent private RouteLocator locator; public RoutesRefreshedEvent(RouteLocator locator) super(locator); this.locator = locator; public RouteLocator getLocator() return this.locator;
在spring-cloud-netflix-core-1.4.4.RELEASE-sources.jar中的org.springframework.cloud.netflix.zuul.zuulZuulServerAutoConfiguration.java配置了监听事件。
private static class ZuulRefreshListener implements ApplicationListener<ApplicationEvent> @Autowired private ZuulHandlerMapping zuulHandlerMapping; private HeartbeatMonitor heartbeatMonitor = new HeartbeatMonitor(); @Override public void onApplicationEvent(ApplicationEvent event) if (event instanceof ContextRefreshedEvent || event instanceof RefreshScopeRefreshedEvent || event instanceof RoutesRefreshedEvent) this.zuulHandlerMapping.setDirty(true); else if (event instanceof HeartbeatEvent) if (this.heartbeatMonitor.update(((HeartbeatEvent) event).getValue())) this.zuulHandlerMapping.setDirty(true);
关于spring的ApplicationEvent见《spring扩展点之三:Spring 的监听事件 ApplicationListener 和 ApplicationEvent 用法,在spring启动后做些事情》
https://blog.csdn.net/weixin_34267123/article/details/86021770
java配置
@Configuration
public class ZuulConfig
@Bean(name="zuul.CONFIGURATION_PROPERTIES")
@RefreshScope
@ConfigurationProperties("zuul")
@Primary
public ZuulProperties zuulProperties()
return new ZuulProperties();
修改路由
到git config server,修改zuul的路由,比如
zuul:
host:
socket-timeout-millis: 60000
connect-timeout-millis: 30000
proxy:
addProxyHeaders: true
routes:
baidu:
path: /baidu
url: http://baidu.com
刷新
curl -i -X POST localhost:10000/refresh
验证
curl -i localhost:10000/routes
作者:go4it
链接:https://www.jianshu.com/p/a9332b111002
來源:简书
简书著作权归作者所有,任何形式的转载都请联系作者获得授权并注明出处。
我们知道在SpringCloud中,当配置变更时,我们通过访问http://xxxx/refresh,可以在不启动服务的情况下获取最新的配置,那么它是如何做到的呢,当我们更改数据库配置并刷新后,如何能获取最新的数据源对象呢?下面我们看SpringCloud如何做到的。
一、环境变化
1.1、关于ContextRefresher
当我们访问/refresh时,会被RefreshEndpoint类所处理。我们来看源代码:
/* * Copyright 2013-2014 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 * * http://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.cloud.endpoint; import java.util.Arrays; import java.util.Collection; import java.util.Set; import org.springframework.boot.actuate.endpoint.AbstractEndpoint; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.cloud.context.refresh.ContextRefresher; import org.springframework.jmx.export.annotation.ManagedOperation; import org.springframework.jmx.export.annotation.ManagedResource; /** * @author Dave Syer * @author Venil Noronha */ @ConfigurationProperties(prefix = "endpoints.refresh", ignoreUnknownFields = false) @ManagedResource public class RefreshEndpoint extends AbstractEndpoint<Collection<String>> private ContextRefresher contextRefresher; public RefreshEndpoint(ContextRefresher contextRefresher) super("refresh"); this.contextRefresher = contextRefresher; @ManagedOperation public String[] refresh() Set<String> keys = contextRefresher.refresh(); return keys.toArray(new String[keys.size()]); @Override public Collection<String> invoke() return Arrays.asList(refresh());
通过源代码我们了解到:当访问refresh端点时,实际上执行的是ContextRefresher的refresh方法,那么我们继续追踪源代码,找到其refresh方法:
public synchronized Set<String> refresh() Map<String, Object> before = extract( this.context.getEnvironment().getPropertySources()); addConfigFilesToEnvironment(); Set<String> keys = changes(before, extract(this.context.getEnvironment().getPropertySources())).keySet(); this.context.publishEvent(new EnvironmentChangeEvent(context, keys)); this.scope.refreshAll(); return keys;
我们可以看到refresh方法做了如下几件事情:
1)获取刷新之前的所有PropertySource
2) 调用addConfigFilesToEnvironment方法获取最新的配置
3) 调用changes方法更新配置信息
4) 发布EnvironmentChangeEnvent事件
5)调用refreshScope的refreshAll方法刷新范围
我们重点关注一下2,3,4步骤
1.2、addConfigFilesToEnvironment方法
我们先来看看这个方法是怎么实现的:
/* for testing */ ConfigurableApplicationContext addConfigFilesToEnvironment() ConfigurableApplicationContext capture = null; try StandardEnvironment environment = copyEnvironment( this.context.getEnvironment()); SpringApplicationBuilder builder = new SpringApplicationBuilder(Empty.class) .bannerMode(Mode.OFF).web(false).environment(environment); // Just the listeners that affect the environment (e.g. excluding logging // listener because it has side effects) builder.application() .setListeners(Arrays.asList(new BootstrapApplicationListener(), new ConfigFileApplicationListener())); capture = builder.run(); if (environment.getPropertySources().contains(REFRESH_ARGS_PROPERTY_SOURCE)) environment.getPropertySources().remove(REFRESH_ARGS_PROPERTY_SOURCE); MutablePropertySources target = this.context.getEnvironment() .getPropertySources(); String targetName = null; for (PropertySource<?> source : environment.getPropertySources()) String name = source.getName(); if (target.contains(name)) targetName = name; if (!this.standardSources.contains(name)) if (target.contains(name)) target.replace(name, source); else if (targetName != null) target.addAfter(targetName, source); else // targetName was null so we are at the start of the list target.addFirst(source); targetName = name; finally ConfigurableApplicationContext closeable = capture; while (closeable != null) try closeable.close(); catch (Exception e) // Ignore; if (closeable.getParent() instanceof ConfigurableApplicationContext) closeable = (ConfigurableApplicationContext) closeable.getParent(); else break; return capture;
1) 该方法首先拷贝当前的Environment
2) 通过SpringApplicationBuilder构建了一个简单的SpringBoot启动程序并启动
builder.application().setListeners(Arrays.asList(new BootstrapApplicationListener(), new ConfigFileApplicationListener()));
这里面会添加两个监听器分别为:BootstrapApplicationListener与ConfigFileApplicationListener,通过先前的学习,我们知道BootstrapApplicationListener是引导程序的核心监听器,而ConfigFileApplicationListener也是非常重要的类:
/* * Copyright 2012-2017 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 * * http://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.boot.context.config; import java.io.IOException; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.Iterator; import java.util.LinkedHashSet; import java.util.LinkedList; import java.util.List; import java.util.Queue; import java.util.Set; import org.apache.commons.logging.Log; import org.springframework.beans.BeansException; import org.springframework.beans.CachedIntrospectionResults; import org.springframework.beans.factory.config.BeanFactoryPostProcessor; import org.springframework.beans.factory.config.ConfigurableListableBeanFactory; import org.springframework.boot.SpringApplication; import org.springframework.boot.bind.PropertiesConfigurationFactory; import org.springframework.boot.bind.PropertySourcesPropertyValues; import org.springframework.boot.bind.RelaxedDataBinder; import org.springframework.boot.bind.RelaxedPropertyResolver; import org.springframework.boot.context.event.ApplicationEnvironmentPreparedEvent; import org.springframework.boot.context.event.ApplicationPreparedEvent; import org.springframework.boot.env.EnumerableCompositePropertySource; import org.springframework.boot.env.EnvironmentPostProcessor; import org.springframework.boot.env.PropertySourcesLoader; import org.springframework.boot.logging.DeferredLog; import org.springframework.context.ApplicationEvent; import org.springframework.context.ConfigurableApplicationContext; import org.springframework.context.annotation.ConfigurationClassPostProcessor; import org.springframework.context.event.SmartApplicationListener; import org.springframework.core.Ordered; import org.springframework.core.annotation.AnnotationAwareOrderComparator; import org.springframework.core.convert.ConversionService; import org.springframework.core.convert.support.DefaultConversionService; import org.springframework.core.env.ConfigurableEnvironment; import org.springframework.core.env.EnumerablePropertySource; import org.springframework.core.env.MutablePropertySources; import org.springframework.core.env.PropertySource; import org.springframework.core.env.PropertySources; import org.springframework.core.io.DefaultResourceLoader; import org.springframework.core.io.Resource; import org.springframework.core.io.ResourceLoader; import org.springframework.core.io.support.SpringFactoriesLoader; import org.springframework.util.Assert; import org.springframework.util.ResourceUtils; import org.springframework.util.StringUtils; import org.springframework.validation.BindException; /** * @link EnvironmentPostProcessor that configures the context environment by loading * properties from well known file locations. By default properties will be loaded from * ‘application.properties‘ and/or ‘application.yml‘ files in the following locations: * <ul> * <li>classpath:</li> * <li>file:./</li> * <li>classpath:config/</li> * <li>file:./config/:</li> * </ul> * <p> * Alternative search locations and names can be specified using * @link #setSearchLocations(String) and @link #setSearchNames(String). * <p> * Additional files will also be loaded based on active profiles. For example if a ‘web‘ * profile is active ‘application-web.properties‘ and ‘application-web.yml‘ will be * considered. * <p> * The ‘spring.config.name‘ property can be used to specify an alternative name to load * and the ‘spring.config.location‘ property can be used to specify alternative search * locations or specific files. * <p> * Configuration properties are also bound to the @link SpringApplication. This makes it * possible to set @link SpringApplication properties dynamically, like the sources * ("spring.main.sources" - a CSV list) the flag to indicate a web environment * ("spring.main.web_environment=true") or the flag to switch off the banner * ("spring.main.show_banner=false"). * * @author Dave Syer * @author Phillip Webb * @author Stephane Nicoll * @author Andy Wilkinson * @author Eddú Meléndez */ public class ConfigFileApplicationListener implements EnvironmentPostProcessor, SmartApplicationListener, Ordered private static final String DEFAULT_PROPERTIES = "defaultProperties"; // Note the order is from least to most specific (last one wins) private static final String DEFAULT_SEARCH_LOCATIONS = "classpath:/,classpath:/config/,file:./,file:./config/"; private static final String DEFAULT_NAMES = "application"; /** * The "active profiles" property name. */ public static final String ACTIVE_PROFILES_PROPERTY = "spring.profiles.active"; /** * The "includes profiles" property name. */ public static final String INCLUDE_PROFILES_PROPERTY = "spring.profiles.include"; /** * The "config name" property name. */ public static final String CONFIG_NAME_PROPERTY = "spring.config.name"; /** * The "config location" property name. */ public static final String CONFIG_LOCATION_PROPERTY = "spring.config.location"; /** * The default order for the processor. */ public static final int DEFAULT_ORDER = Ordered.HIGHEST_PRECEDENCE + 10; /** * Name of the application configuration @link PropertySource. */ public static final String APPLICATION_CONFIGURATION_PROPERTY_SOURCE_NAME = "applicationConfigurationProperties"; private final DeferredLog logger = new DeferredLog(); private String searchLocations; private String names; private int order = DEFAULT_ORDER; private final ConversionService conversionService = new DefaultConversionService(); @Override public boolean supportsEventType(Class<? extends ApplicationEvent> eventType) return ApplicationEnvironmentPreparedEvent.class.isAssignableFrom(eventType) || ApplicationPreparedEvent.class.isAssignableFrom(eventType); @Override public boolean supportsSourceType(Class<?> aClass) return true; @Override public void onApplicationEvent(ApplicationEvent event) if (event instanceof ApplicationEnvironmentPreparedEvent) onApplicationEnvironmentPreparedEvent( (ApplicationEnvironmentPreparedEvent) event); if (event instanceof ApplicationPreparedEvent) onApplicationPreparedEvent(event); private void onApplicationEnvironmentPreparedEvent( ApplicationEnvironmentPreparedEvent event) List<EnvironmentPostProcessor> postProcessors = loadPostProcessors(); postProcessors.add(this); AnnotationAwareOrderComparator.sort(postProcessors); for (EnvironmentPostProcessor postProcessor : postProcessors) postProcessor.postProcessEnvironment(event.getEnvironment(), event.getSpringApplication()); List<EnvironmentPostProcessor> loadPostProcessors() return SpringFactoriesLoader.loadFactories(EnvironmentPostProcessor.class, getClass().getClassLoader()); @Override public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) addPropertySources(environment, application.getResourceLoader()); configureIgnoreBeanInfo(environment); bindToSpringApplication(environment, application); private void configureIgnoreBeanInfo(ConfigurableEnvironment environment) if (System.getProperty( CachedIntrospectionResults.IGNORE_BEANINFO_PROPERTY_NAME) == null) RelaxedPropertyResolver resolver = new RelaxedPropertyResolver(environment, "spring.beaninfo."); Boolean ignore = resolver.getProperty("ignore", Boolean.class, Boolean.TRUE); System.setProperty(CachedIntrospectionResults.IGNORE_BEANINFO_PROPERTY_NAME, ignore.toString()); private void onApplicationPreparedEvent(ApplicationEvent event) this.logger.replayTo(ConfigFileApplicationListener.class); addPostProcessors(((ApplicationPreparedEvent) event).getApplicationContext()); /** * Add config file property sources to the specified environment. * @param environment the environment to add source to * @param resourceLoader the resource loader * @see #addPostProcessors(ConfigurableApplicationContext) */ protected void addPropertySources(ConfigurableEnvironment environment, ResourceLoader resourceLoader) RandomValuePropertySource.addToEnvironment(environment); new Loader(environment, resourceLoader).load(); /** * Bind the environment to the @link SpringApplication. * @param environment the environment to bind * @param application the application to bind to */ protected void bindToSpringApplication(ConfigurableEnvironment environment, SpringApplication application) PropertiesConfigurationFactory<SpringApplication> binder = new PropertiesConfigurationFactory<SpringApplication>( application); binder.setTargetName("spring.main"); binder.setConversionService(this.conversionService); binder.setPropertySources(environment.getPropertySources()); try binder.bindPropertiesToTarget(); catch (BindException ex) throw new IllegalStateException("Cannot bind to SpringApplication", ex); /** * Add appropriate post-processors to post-configure the property-sources. * @param context the context to configure */ protected void addPostProcessors(ConfigurableApplicationContext context) context.addBeanFactoryPostProcessor( new PropertySourceOrderingPostProcessor(context)); public void setOrder(int order) this.order = order; @Override public int getOrder() return this.order; /** * Set the search locations that will be considered as a comma-separated list. Each * search location should be a directory path (ending in "/") and it will be prefixed * by the file names constructed from @link #setSearchNames(String) search names and * profiles (if any) plus file extensions supported by the properties loaders. * Locations are considered in the order specified, with later items taking precedence * (like a map merge). * @param locations the search locations */ public void setSearchLocations(String locations) Assert.hasLength(locations, "Locations must not be empty"); this.searchLocations = locations; /** * Sets the names of the files that should be loaded (excluding file extension) as a * comma-separated list. * @param names the names to load */ public void setSearchNames(String names) Assert.hasLength(names, "Names must not be empty"); this.names = names; /** * @link BeanFactoryPostProcessor to re-order our property sources below any * @code @PropertySource items added by the @link ConfigurationClassPostProcessor. */ private class PropertySourceOrderingPostProcessor implements BeanFactoryPostProcessor, Ordered private ConfigurableApplicationContext context; PropertySourceOrderingPostProcessor(ConfigurableApplicationContext context) this.context = context; @Override public int getOrder() return Ordered.HIGHEST_PRECEDENCE; @Override public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException reorderSources(this.context.getEnvironment()); private void reorderSources(ConfigurableEnvironment environment) ConfigurationPropertySources .finishAndRelocate(environment.getPropertySources()); PropertySource<?> defaultProperties = environment.getPropertySources() .remove(DEFAULT_PROPERTIES); if (defaultProperties != null) environment.getPropertySources().addLast(defaultProperties); /** * Loads candidate property sources and configures the active profiles. */ private class Loader private final Log logger = ConfigFileApplicationListener.this.logger; private final ConfigurableEnvironment environment; private final ResourceLoader resourceLoader; private PropertySourcesLoader propertiesLoader; private Queue<Profile> profiles; private List<Profile> processedProfiles; private boolean activatedProfiles; Loader(ConfigurableEnvironment environment, ResourceLoader resourceLoader) this.environment = environment; this.resourceLoader = resourceLoader == null ? new DefaultResourceLoader() : resourceLoader; public void load() this.propertiesLoader = new PropertySourcesLoader(); this.activatedProfiles = false; this.profiles = Collections.asLifoQueue(new LinkedList<Profile>()); this.processedProfiles = new LinkedList<Profile>(); // Pre-existing active profiles set via Environment.setActiveProfiles() // are additional profiles and config files are allowed to add more if // they want to, so don‘t call addActiveProfiles() here. Set<Profile> initialActiveProfiles = initializeActiveProfiles(); this.profiles.addAll(getUnprocessedActiveProfiles(initialActiveProfiles)); if (this.profiles.isEmpty()) for (String defaultProfileName : this.environment.getDefaultProfiles()) Profile defaultProfile = new Profile(defaultProfileName, true); if (!this.profiles.contains(defaultProfile)) this.profiles.add(defaultProfile); // The default profile for these purposes is represented as null. We add it // last so that it is first out of the queue (active profiles will then // override any settings in the defaults when the list is reversed later). this.profiles.add(null); while (!this.profiles.isEmpty()) Profile profile = this.profiles.poll(); for (String location : getSearchLocations()) if (!location.endsWith("/")) // location is a filename already, so don‘t search for more // filenames load(location, null, profile); else for (String name : getSearchNames()) load(location, name, profile); this.processedProfiles.add(profile); addConfigurationProperties(this.propertiesLoader.getPropertySources()); private Set<Profile> initializeActiveProfiles() if (!this.environment.containsProperty(ACTIVE_PROFILES_PROPERTY) && !this.environment.containsProperty(INCLUDE_PROFILES_PROPERTY)) return Collections.emptySet(); // Any pre-existing active profiles set via property sources (e.g. System // properties) take precedence over those added in config files. SpringProfiles springProfiles = bindSpringProfiles( this.environment.getPropertySources()); Set<Profile> activeProfiles = new LinkedHashSet<Profile>( springProfiles.getActiveProfiles()); activeProfiles.addAll(springProfiles.getIncludeProfiles()); maybeActivateProfiles(activeProfiles); return activeProfiles; /** * Return the active profiles that have not been processed yet. If a profile is * enabled via both @link #ACTIVE_PROFILES_PROPERTY and * @link ConfigurableEnvironment#addActiveProfile(String) it needs to be * filtered so that the @link #ACTIVE_PROFILES_PROPERTY value takes precedence. * <p> * Concretely, if the "cloud" profile is enabled via the environment, it will take * less precedence that any profile set via the @link #ACTIVE_PROFILES_PROPERTY. * @param initialActiveProfiles the profiles that have been enabled via * @link #ACTIVE_PROFILES_PROPERTY * @return the unprocessed active profiles from the environment to enable */ private List<Profile> getUnprocessedActiveProfiles( Set<Profile> initialActiveProfiles) List<Profile> unprocessedActiveProfiles = new ArrayList<Profile>(); for (String profileName : this.environment.getActiveProfiles()) Profile profile = new Profile(profileName); if (!initialActiveProfiles.contains(profile)) unprocessedActiveProfiles.add(profile); // Reverse them so the order is the same as from getProfilesForValue() // (last one wins when properties are eventually resolved) Collections.reverse(unprocessedActiveProfiles); return unprocessedActiveProfiles; private void load(String location, String name, Profile profile) String group = "profile=" + (profile == null ? "" : profile); if (!StringUtils.hasText(name)) // Try to load directly from the location loadIntoGroup(group, location, profile); else // Search for a file with the given name for (String ext : this.propertiesLoader.getAllFileExtensions()) if (profile != null) // Try the profile-specific file loadIntoGroup(group, location + name + "-" + profile + "." + ext, null); for (Profile processedProfile : this.processedProfiles) if (processedProfile != null) loadIntoGroup(group, location + name + "-" + processedProfile + "." + ext, profile); // Sometimes people put "spring.profiles: dev" in // application-dev.yml (gh-340). Arguably we should try and error // out on that, but we can be kind and load it anyway. loadIntoGroup(group, location + name + "-" + profile + "." + ext, profile); // Also try the profile-specific section (if any) of the normal file loadIntoGroup(group, location + name + "." + ext, profile); private PropertySource<?> loadIntoGroup(String identifier, String location, Profile profile) try return doLoadIntoGroup(identifier, location, profile); catch (Exception ex) throw new IllegalStateException( "Failed to load property source from location ‘" + location + "‘", ex); private PropertySource<?> doLoadIntoGroup(String identifier, String location, Profile profile) throws IOException Resource resource = this.resourceLoader.getResource(location); PropertySource<?> propertySource = null; StringBuilder msg = new StringBuilder(); if (resource != null && resource.exists()) String name = "applicationConfig: [" + location + "]"; String group = "applicationConfig: [" + identifier + "]"; propertySource = this.propertiesLoader.load(resource, group, name, (profile == null ? null : profile.getName())); if (propertySource != null) msg.append("Loaded "); handleProfileProperties(propertySource); else msg.append("Skipped (empty) "); else msg.append("Skipped "); msg.append("config file "); msg.append(getResourceDescription(location, resource)); if (profile != null) msg.append(" for profile ").append(profile); if (resource == null || !resource.exists()) msg.append(" resource not found"); this.logger.trace(msg); else this.logger.debug(msg); return propertySource; private String getResourceDescription(String location, Resource resource) String resourceDescription = "‘" + location + "‘"; if (resource != null) try resourceDescription = String.format("‘%s‘ (%s)", resource.getURI().toASCIIString(), location); catch (IOException ex) // Use the location as the description return resourceDescription; private void handleProfileProperties(PropertySource<?> propertySource) SpringProfiles springProfiles = bindSpringProfiles(propertySource); maybeActivateProfiles(springProfiles.getActiveProfiles()); addProfiles(springProfiles.getIncludeProfiles()); private SpringProfiles bindSpringProfiles(PropertySource<?> propertySource) MutablePropertySources propertySources = new MutablePropertySources(); propertySources.addFirst(propertySource); return bindSpringProfiles(propertySources); private SpringProfiles bindSpringProfiles(PropertySources propertySources) SpringProfiles springProfiles = new SpringProfiles(); RelaxedDataBinder dataBinder = new RelaxedDataBinder(springProfiles, "spring.profiles"); dataBinder.bind(new PropertySourcesPropertyValues(propertySources, false)); springProfiles.setActive(resolvePlaceholders(springProfiles.getActive())); springProfiles.setInclude(resolvePlaceholders(springProfiles.getInclude())); return springProfiles; private List<String> resolvePlaceholders(List<String> values) List<String> resolved = new ArrayList<String>(); for (String value : values) resolved.add(this.environment.resolvePlaceholders(value)); return resolved; private void maybeActivateProfiles(Set<Profile> profiles) if (this.activatedProfiles) if (!profiles.isEmpty()) this.logger.debug("Profiles already activated, ‘" + profiles + "‘ will not be applied"); return; if (!profiles.isEmpty()) addProfiles(profiles); this.logger.debug("Activated profiles " + StringUtils.collectionToCommaDelimitedString(profiles)); this.activatedProfiles = true; removeUnprocessedDefaultProfiles(); private void removeUnprocessedDefaultProfiles() for (Iterator<Profile> iterator = this.profiles.iterator(); iterator .hasNext();) if (iterator.next().isDefaultProfile()) iterator.remove(); private void addProfiles(Set<Profile> profiles) for (Profile profile : profiles) this.profiles.add(profile); if (!environmentHasActiveProfile(profile.getName())) // If it‘s already accepted we assume the order was set // intentionally prependProfile(this.environment, profile); private boolean environmentHasActiveProfile(String profile) for (String activeProfile : this.environment.getActiveProfiles()) if (activeProfile.equals(profile)) return true; return false; private void prependProfile(ConfigurableEnvironment environment, Profile profile) Set<String> profiles = new LinkedHashSet<String>(); environment.getActiveProfiles(); // ensure they are initialized // But this one should go first (last wins in a property key clash) profiles.add(profile.getName()); profiles.addAll(Arrays.asList(environment.getActiveProfiles())); environment.setActiveProfiles(profiles.toArray(new String[profiles.size()])); private Set<String> getSearchLocations() Set<String> locations = new LinkedHashSet<String>(); // User-configured settings take precedence, so we do them first if (this.environment.containsProperty(CONFIG_LOCATION_PROPERTY)) for (String path : asResolvedSet( this.environment.getProperty(CONFIG_LOCATION_PROPERTY), null)) if (!path.contains("$")) path = StringUtils.cleanPath(path); if (!ResourceUtils.isUrl(path)) path = ResourceUtils.FILE_URL_PREFIX + path; locations.add(path); locations.addAll( asResolvedSet(ConfigFileApplicationListener.this.searchLocations, DEFAULT_SEARCH_LOCATIONS)); return locations; private Set<String> getSearchNames() if (this.environment.containsProperty(CONFIG_NAME_PROPERTY)) return asResolvedSet(this.environment.getProperty(CONFIG_NAME_PROPERTY), null); return asResolvedSet(ConfigFileApplicationListener.this.names, DEFAULT_NAMES); private Set<String> asResolvedSet(String value, String fallback) List<String> list = Arrays.asList(StringUtils.trimArrayElements( StringUtils.commaDelimitedListToStringArray(value != null ? this.environment.resolvePlaceholders(value) : fallback))); Collections.reverse(list); return new LinkedHashSet<String>(list); private void addConfigurationProperties(MutablePropertySources sources) List<PropertySource<?>> reorderedSources = new ArrayList<PropertySource<?>>(); for (PropertySource<?> item : sources) reorderedSources.add(item); addConfigurationProperties( new ConfigurationPropertySources(reorderedSources)); private void addConfigurationProperties( ConfigurationPropertySources configurationSources) MutablePropertySources existingSources = this.environment .getPropertySources(); if (existingSources.contains(DEFAULT_PROPERTIES)) existingSources.addBefore(DEFAULT_PROPERTIES, configurationSources); else existingSources.addLast(configurationSources); private static class Profile private final String name; private final boolean defaultProfile; Profile(String name) this(name, false); Profile(String name, boolean defaultProfile) Assert.notNull(name, "Name must not be null"); this.name = name; this.defaultProfile = defaultProfile; public String getName() return this.name; public boolean isDefaultProfile() return this.defaultProfile; @Override public String toString() return this.name; @Override public int hashCode() return this.name.hashCode(); @Override public boolean equals(Object obj) if (obj == this) return true; if (obj == null || obj.getClass() != getClass()) return false; return ((Profile) obj).name.equals(this.name); /** * Holds the configuration @link PropertySources as they are loaded can relocate * them once configuration classes have been processed. */ static class ConfigurationPropertySources extends EnumerablePropertySource<Collection<PropertySource<?>>> private final Collection<PropertySource<?>> sources; private final String[] names; ConfigurationPropertySources(Collection<PropertySource<?>> sources) super(APPLICATION_CONFIGURATION_PROPERTY_SOURCE_NAME, sources); this.sources = sources; List<String> names = new ArrayList<String>(); for (PropertySource<?> source : sources) if (source instanceof EnumerablePropertySource) names.addAll(Arrays.asList( ((EnumerablePropertySource<?>) source).getPropertyNames())); this.names = names.toArray(new String[names.size()]); @Override public Object getProperty(String name) for (PropertySource<?> propertySource : this.sources) Object value = propertySource.getProperty(name); if (value != null) return value; return null; public static void finishAndRelocate(MutablePropertySources propertySources) String name = APPLICATION_CONFIGURATION_PROPERTY_SOURCE_NAME; ConfigurationPropertySources removed = (ConfigurationPropertySources) propertySources .get(name); if (removed != null) for (PropertySource<?> propertySource : removed.sources) if (propertySource instanceof EnumerableCompositePropertySource) EnumerableCompositePropertySource composite = (EnumerableCompositePropertySource) propertySource; for (PropertySource<?> nested : composite.getSource()) propertySources.addAfter(name, nested); name = nested.getName(); else propertySources.addAfter(name, propertySource); propertySources.remove(APPLICATION_CONFIGURATION_PROPERTY_SOURCE_NAME); @Override public String[] getPropertyNames() return this.names; /** * Holder for @code spring.profiles properties. */ static final class SpringProfiles private List<String> active = new ArrayList<String>(); private List<String> include = new ArrayList<String>(); public List<String> getActive() return this.active; public void setActive(List<String> active) this.active = active; public List<String> getInclude() return this.include; public void setInclude(List<String> include) this.include = include; Set<Profile> getActiveProfiles() return asProfileSet(this.active); Set<Profile> getIncludeProfiles() return asProfileSet(this.include); private Set<Profile> asProfileSet(List<String> profileNames) List<Profile> profiles = new ArrayList<Profile>(); for (String profileName : profileNames) profiles.add(new Profile(profileName)); Collections.reverse(profiles); return new LinkedHashSet<Profile>(profiles);
根据javadoc注释的说明,这个类会从指定的位置加载application.properties或者application.yml并将它们的属性读到Envrionment当中,其中这几个方法大家关注下:
@Override public void onApplicationEvent(ApplicationEvent event) if (event instanceof ApplicationEnvironmentPreparedEvent) onApplicationEnvironmentPreparedEvent( (ApplicationEnvironmentPreparedEvent) event); if (event instanceof ApplicationPreparedEvent) onApplicationPreparedEvent(event);
当springboot程序启动时一定会触发该事件监听,如果当前是 ApplicationEnvironmentPreparedEvent事件就会调用 onApplicationEnvironmentPreparedEvent方法,最终该方法会执行:
@Override public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) addPropertySources(environment, application.getResourceLoader()); configureIgnoreBeanInfo(environment); bindToSpringApplication(environment, application);
其中 bindToSpringApplication方法为:
/** * Bind the environment to the @link SpringApplication. * @param environment the environment to bind * @param application the application to bind to */ protected void bindToSpringApplication(ConfigurableEnvironment environment, SpringApplication application) PropertiesConfigurationFactory<SpringApplication> binder = new PropertiesConfigurationFactory<SpringApplication>( application); binder.setTargetName("spring.main"); binder.setConversionService(this.conversionService); binder.setPropertySources(environment.getPropertySources()); try binder.bindPropertiesToTarget(); catch (BindException ex) throw new IllegalStateException("Cannot bind to SpringApplication", ex);
很明显该方法是将Environment绑定到对应SpringApplication上,通过这个类就可以获取到我们更改过后的配置了
1.3、changes方法
private Map<String, Object> changes(Map<String, Object> before, Map<String, Object> after) Map<String, Object> result = new HashMap<String, Object>(); for (String key : before.keySet()) if (!after.containsKey(key)) result.put(key, null); else if (!equal(before.get(key), after.get(key))) result.put(key, after.get(key)); for (String key : after.keySet()) if (!before.containsKey(key)) result.put(key, after.get(key)); return result;
changes方法其实就是处理配置变更信息的,分以下几种情况:
1)如果刷新过后配置文件新增配置就添加到Map里
2) 如果有配置变更就添加变更后的配置
3) 如果删除了原先的配置,就把原先的key对应的值设置为null
至此经过changes方法后,上下文环境已经拥有最新的配置了。
1.4、发布事件
当上述步骤都执行完毕后,紧接着会发布EnvrionmentChangeEvent事件,可是这个事件谁来监听呢?在这里我贴出官网的一段描述:
应用程序将收听EnvironmentChangeEvent,并以几种标准方式进行更改(用户可以以常规方式添加ApplicationListeners附加ApplicationListeners)。当观察到EnvironmentChangeEvent时,它将有一个已更改的键值列表,应用程序将使用以下内容: 1.重新绑定上下文中的任何@ConfigurationProperties bean 2.为logging.level.*中的任何属性设置记录器级别
根据官网描述我们知道将变更一下操作行为@ConfigurationProperties的bean与更改日志level,那么如何做到的呢?结合官网文档我们来关注以下两个类:
ConfigurationPropertiesRebinder:
我们可以看到该类监听了ChangeEnvrionmentEvent事件,它最主要作用是拿到更新的配置以后,重新绑定@ConfigurationProperties标记的类使之能够读取最新的属性
LoggingRebinder:
该类也是监听了ChangeEnvrionmentEvent事件,用于重新绑定日志级别
二、刷新范围
我们考虑如下场景,当我们变更数据库配置后,通过refresh刷新,虽然能获取到最新的配置,可是我们的DataSource对象早就被初始化好了,换句话说即便配置刷新了我们拿到的依然是配置刷新前的对象。怎么解决这个问题呢?
我们继续看ContextRefresher的refresh方法,最后有一处代码值得我们关注一下this.scope.refreshAll(),此处scope对象是RefreshScope类型,那么这个类有什么作用呢?那么我们先要关注一下@RefreshScope注解。在这里我在贴出官网一段解释:
当配置更改时,标有@RefreshScope的Spring @Bean将得到特殊处理。这解决了状态bean在初始化时只注入配置的问题。例如,如果通过Environment更改数据库URL时DataSource有开放连接,那么我们可能希望这些连接的持有人能够完成他们正在做的工作。然后下一次有人从游泳池借用一个连接,他得到一个新的URL
刷新范围bean是在使用时初始化的懒惰代理(即当调用一个方法时),并且作用域作为初始值的缓存。要强制bean重新初始化下一个方法调用,您只需要使其缓存条目无效。RefreshScope
是上下文中的一个bean,它有一个公共方法refreshAll()
来清除目标缓存中的范围内的所有bean。还有一个refresh(String)
方法可以按名称刷新单个bean。此功能在/refresh
端点(通过HTTP或JMX)中公开。
这里我贴出@RefreshScope源码:
在这个注解上我们关注一下此处标记了@Scope("refresh"),我们知道Spring的Bean属性有个叫scope的,它定义了bean的作用范围,常见的有singleon,prototype,session等。此处新定义了一个范围叫做refresh,在此我贴出RefreshScope的源代码来分析一下:
该类继承了GenericScope:
这里面我们先看一下RefreshScope的构造函数:
/** * Create a scope instance and give it the default name: "refresh". */ public RefreshScope() super.setName("refresh");
这里面创建了一个名字为refresh的scope。
紧接着在它的父类里我们可以看一下这个方法:
@Override public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException this.beanFactory = beanFactory; beanFactory.registerScope(this.name, this); setSerializationId(beanFactory);
此方法中使用BeanFactory注册了一个refresh的范围,使得scope为refresh的bean生效。@RefreshScope标注的类还有一个特点:会使用代理对象并进行延迟加载。我们来看一下postProcessBeanDefinitionRegistry方法
@Override public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) throws BeansException for (String name : registry.getBeanDefinitionNames()) BeanDefinition definition = registry.getBeanDefinition(name); if (definition instanceof RootBeanDefinition) RootBeanDefinition root = (RootBeanDefinition) definition; if (root.getDecoratedDefinition() != null && root.hasBeanClass() && root.getBeanClass() == ScopedProxyFactoryBean.class) if (getName().equals(root.getDecoratedDefinition().getBeanDefinition() .getScope())) root.setBeanClass(LockedScopedProxyFactoryBean.class);
该方法遍历所有的bean定义 如果当前的bean的scope为refresh,那么就把当前的bean设置为 LockedScopedProxyFactoryBean的代理对象。
RefreshScope还会监听一个ContextRefreshedEvent,该事件会在ApplicationContext初始化或者refreshed时触发,我们来看一下代码:
@EventListener public void start(ContextRefreshedEvent event) if (event.getApplicationContext() == this.context && this.eager && this.registry != null) eagerlyInitialize(); private void eagerlyInitialize() for (String name : this.context.getBeanDefinitionNames()) BeanDefinition definition = this.registry.getBeanDefinition(name); if (this.getName().equals(definition.getScope()) && !definition.isLazyInit()) Object bean = this.context.getBean(name); if (bean != null) bean.getClass();
注意此处获取refreshscope的bean,其中getBean是一个复杂而又繁琐的过程,此处我们先不在这里讨论,只不过经过这个方法以后,其通过代理机制会在GernericScope的BeanLifecycleWrapperCache缓存里把这个@RefreshScope标记的bean添加进去。
最后我们回过头来看一看RefreshScope的refreshAll方法:
@ManagedOperation(description = "Dispose of the current instance of all beans in this scope and force a refresh on next method execution.") public void refreshAll() super.destroy(); this.context.publishEvent(new RefreshScopeRefreshedEvent()); //.......GernericScope的destroy方法 @Override public void destroy() List<Throwable> errors = new ArrayList<Throwable>(); Collection<BeanLifecycleWrapper> wrappers = this.cache.clear(); for (BeanLifecycleWrapper wrapper : wrappers) try Lock lock = locks.get(wrapper.getName()).writeLock(); lock.lock(); try wrapper.destroy(); finally lock.unlock(); catch (RuntimeException e) errors.add(e); if (!errors.isEmpty()) throw wrapIfNecessary(errors.get(0)); this.errors.clear();
这里的代码逻辑很简单清除与释放缓存里被@RefreshScope标记的bean 。
当我们要获取对象时,我们可以关注如下方法:
@Override public Object get(String name, ObjectFactory<?> objectFactory) BeanLifecycleWrapper value = this.cache.put(name, new BeanLifecycleWrapper(name, objectFactory)); locks.putIfAbsent(name, new ReentrantReadWriteLock()); try return value.getBean(); catch (RuntimeException e) this.errors.put(name, e); throw e; //..... BeanLifecycleWrapper的方法 public Object getBean() if (this.bean == null) synchronized (this.name) if (this.bean == null) this.bean = this.objectFactory.getObject(); return this.bean;
BeanLifecycleWrapper这个是@RefreshScope标记bean的一个包装类,会被存储到缓存里,在这里取不到值的话就会从objectFactory里去拿
三、示例与总结
3.1、示例
创建AppConfig类代码如下:
package com.bdqn.lyrk.refresh.scope.server; import org.springframework.boot.context.properties.EnableConfigurationProperties; import org.springframework.cloud.context.config.annotation.RefreshScope; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; @Configuration @EnableConfigurationProperties(StudentConfig.class) public class AppConfig @RefreshScope @Bean public Student student(StudentConfig config) Student student = new Student(); student.setName(config.getName()); return student;
在这里,将Student设置为@RefreshScope 那么刷新以后会获取最新的Bean
启动类:
package com.bdqn.lyrk.refresh.scope.server; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; @SpringBootApplication @RestController public class RefreshScopeApplication @Autowired private Student student; @GetMapping public String student() return student.getName(); public static void main(String[] args) throws InterruptedException SpringApplication.run(RefreshScopeApplication.class, args);
application.yml文件:
spring: application: name: refresh-scope-server endpoints: refresh: sensitive: false server: port: 8089 student: name: admin
这里把refresh端点开放出来,然后变更配置后就可以获取最新的对象了
3.2、总结
1) 当配置更新并通过refresh端点刷新后,会执行ContextRefresher的refresh方法,该方法会记录当前的Environment,而后构建一个简易的SpringApplicationBuilder并执行其run方法,此时ConfigFileApplicationListener会读取我们修改过后的配置并绑定到SpringApplication对象上,最后进行changes操作来变更已有的PropertySource
2) @RefreshScope最好配合@Bean使用,当且仅当变更配置后,需要重新获取最新的bean时使用。加上该注解的Bean会被代理并且延迟加载,所有的scope属性为Refresh的bean会被包装成BeanLifecycleWrapper存入缓存(ConcurrentHashMap)中,所有的读取,修改,删除都是基于该缓存的
原文地址:https://www.cnblogs.com/softidea/p/10427041.html