SpringSecurity6从入门到上天系列第六篇：解决这个问题为什么在引入SpringSecurity之后所有的请求都需要先做登录认证才可以进行访问呢

文章目录

问题引入

1：问题阐述

2：问题分析

一：从SpringBoot的自动装配

1：@SpringBootApplication介绍

2：自动装配的核心方法

3：核心方法的调用路径

4：SpringSecurity核心配置

5：SpringBoot...Configuration详解

6：总结一下

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本专栏简介：话不多说，让我们一起干翻SpringSecurity6

本文章简介：话不多说，让我们讲清楚SpringSecurity6中为什么在引入SpringSecurity之后所有的请求都需要先做登录认证才可以进行访问呢

问题引入

1：问题阐述

        为什么在引入SpringSecurity之后所有的请求都需要先做登录认证才可以进行访问呢？

2：问题分析

        分析清楚这个问题之前，我们先从自动装配开始研究。

一：从SpringBoot的自动装配

1：@SpringBootApplication介绍

        这个注解的作用就是标志这个类是SpringBootApplication的启动类。

@SpringBootApplication
public class BigtreeApplication {public static void main(String[] args) {SpringApplication.run(BigtreeApplication.class, args);}
}

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
@SpringBootConfiguration
@EnableAutoConfiguration
@ComponentScan(excludeFilters = {@Filter(type = FilterType.CUSTOM,classes = {TypeExcludeFilter.class}
), @Filter(type = FilterType.CUSTOM,classes = {AutoConfigurationExcludeFilter.class}
)}
)
public @interface SpringBootApplication {@AliasFor(annotation = EnableAutoConfiguration.class)Class<?>[] exclude() default {};@AliasFor(annotation = EnableAutoConfiguration.class)String[] excludeName() default {};@AliasFor(annotation = ComponentScan.class,attribute = "basePackages")String[] scanBasePackages() default {};@AliasFor(annotation = ComponentScan.class, attribute = "basePackageClasses")Class<?>[] scanBasePackageClasses() default {};@AliasFor(annotation = ComponentScan.class,attribute = "nameGenerator")Class<? extends BeanNameGenerator> nameGenerator() default BeanNameGenerator.class;@AliasFor( annotation = Configuration.class)boolean proxyBeanMethods() default true;
}

       

        这个注解是一个复合注解@SpringBootConfiguration这个注解的作用带表了这当前这个类是一个SpringBoot配置类，自动交给SpringIOC容器进行管理。

        第二个注解是ComponentScan这个注解的作用是定义Spring的扫描路径的。通畅对应我们自己定义的组件例如：Controller，Service，Dao这些组件。

        第三个注解是：@EnableAutoConfiguration这个注解是SpringBoot自动装配的关键注解，这个注解包含两个核心注解

        第一个注解是：@Import({AutoConfigurationImportSelector.class})这个注解的作用就是在导入当前类的同时顺便导入AutoConfigurationImportSelector这个类也加载进来。

2：自动装配的核心方法

org.springframework.boot.autoconfigure.AutoConfigurationImportSelector#getCandidateConfigurations	
protected List<String> getCandidateConfigurations(AnnotationMetadata metadata, AnnotationAttributes attributes) {List<String> configurations = ImportCandidates.load(AutoConfiguration.class, getBeanClassLoader()).getCandidates();Assert.notEmpty(configurations,"No auto configuration classes found in "+ "META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports. If you "+ "are using a custom packaging, make sure that file is correct.");return configurations;}

org.springframework.boot.context.annotation.ImportCandidates	
public static ImportCandidates load(Class<?> annotation, ClassLoader classLoader) {Assert.notNull(annotation, "'annotation' must not be null");ClassLoader classLoaderToUse = decideClassloader(classLoader);String location = String.format(LOCATION, annotation.getName());Enumeration<URL> urls = findUrlsInClasspath(classLoaderToUse, location);List<String> importCandidates = new ArrayList<>();while (urls.hasMoreElements()) {URL url = urls.nextElement();importCandidates.addAll(readCandidateConfigurations(url));}return new ImportCandidates(importCandidates);}

        此方法执行完毕的返回值：

        这个配置在：spring-boot-autoconfigure-3.0.12.jar包下!\META-INF\spring\包下的

        org.springframework.boot.autoconfigure.AutoConfiguration.imports文件中，这里边就是Spring中的各种需要自动装配的组件。其中就有很多的配置组件。

3：核心方法的调用路径

"main@1" prio=5 tid=0x1 nid=NA runnablejava.lang.Thread.State: RUNNABLEat org.springframework.boot.context.annotation.ImportCandidates.load(ImportCandidates.java:90)at org.springframework.boot.autoconfigure.AutoConfigurationImportSelector.getCandidateConfigurations(AutoConfigurationImportSelector.java:180)at org.springframework.boot.autoconfigure.AutoConfigurationImportSelector.getAutoConfigurationEntry(AutoConfigurationImportSelector.java:126)at org.springframework.boot.autoconfigure.AutoConfigurationImportSelector$AutoConfigurationGroup.process(AutoConfigurationImportSelector.java:430)at org.springframework.context.annotation.ConfigurationClassParser$DeferredImportSelectorGrouping.getImports(ConfigurationClassParser.java:796)at org.springframework.context.annotation.ConfigurationClassParser$DeferredImportSelectorGroupingHandler.processGroupImports(ConfigurationClassParser.java:726)at org.springframework.context.annotation.ConfigurationClassParser$DeferredImportSelectorHandler.process(ConfigurationClassParser.java:697)at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:182)at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:415)at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:287)at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:344)at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:115)at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:779)at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:597)- locked <0x12a7> (a java.lang.Object)at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146)at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:733)at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:435)at org.springframework.boot.SpringApplication.run(SpringApplication.java:311)at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301)at org.springframework.boot.SpringApplication.run(SpringApplication.java:1290)at com.dashu.AlibabaApplication.main(AlibabaApplication.java:10)

        这个调用路径是怎么获得的？方法很简单，只需要在这个核心方法的中间打上一个断点。

        然后我们启动main方法，等线程执行过这个方法的断点。然后我们在idea上玩一个骚操作就可以了。

        然后，我们在debug区域，找到最上层一个方法，然后我们右键Exports Thread即可。 

4：SpringSecurity核心配置

org.springframework.boot.autoconfigure.security.servlet.SecurityAutoConfiguration

@AutoConfiguration
@ConditionalOnClass(DefaultAuthenticationEventPublisher.class)
@EnableConfigurationProperties(SecurityProperties.class)
@Import({ SpringBootWebSecurityConfiguration.class, SecurityDataConfiguration.class })
public class SecurityAutoConfiguration {@Bean@ConditionalOnMissingBean(AuthenticationEventPublisher.class)public DefaultAuthenticationEventPublisher authenticationEventPublisher(ApplicationEventPublisher publisher) {return new DefaultAuthenticationEventPublisher(publisher);}}

        然后，就会加载这两个组件：SpringBootWebSecurityConfiguration.class, SecurityDataConfiguration.class 尤其是第一个。

5：SpringBoot...Configuration详解

        这里边只有一个@Bean注解，最终会创建一个对象：SecurityFilterChain，为什么最终引入了SpringSecurity依赖之后就会所有的请求都会被拦截答案就在这个方法里边。

		@Bean@Order(SecurityProperties.BASIC_AUTH_ORDER)SecurityFilterChain defaultSecurityFilterChain(HttpSecurity http) throws Exception {//任意Http请求都会被认证拦截http.authorizeHttpRequests().anyRequest().authenticated();//认证的时候支持form表单认证http.formLogin();//http的basic认证http.httpBasic();return http.build();}

@Configuration(proxyBeanMethods = false)
@ConditionalOnWebApplication(type = Type.SERVLET)
class SpringBootWebSecurityConfiguration {@Configuration(proxyBeanMethods = false)@ConditionalOnDefaultWebSecuritystatic class SecurityFilterChainConfiguration {@Bean@Order(SecurityProperties.BASIC_AUTH_ORDER)SecurityFilterChain defaultSecurityFilterChain(HttpSecurity http) throws Exception {http.authorizeHttpRequests().anyRequest().authenticated();http.formLogin();http.httpBasic();return http.build();}}@Configuration(proxyBeanMethods = false)@ConditionalOnMissingBean(name = BeanIds.SPRING_SECURITY_FILTER_CHAIN)@ConditionalOnClass(EnableWebSecurity.class)@EnableWebSecuritystatic class WebSecurityEnablerConfiguration {}}

6：总结一下

        基于SpringBoot的自动装配，由于SpringSecurity的装配配置在SpringBoot配置环境中，所以它默认会被加载，加载完毕之后defaultSecurityFilterChain被调用，SecurityFilterChain对象被创创建。所有的方法都会被被鉴权。

        具体的方法调用路径或者叫配置路径是这样的：首先是三个核心的注解：

@SpringBootApplication-> @EnableAutoConfiguration>@Import(AutoConfigurationImportSelector)

       这样的代码就会基于下面这个调用路径：

"main@1" prio=5 tid=0x1 nid=NA runnablejava.lang.Thread.State: RUNNABLEat org.springframework.boot.context.annotation.ImportCandidates.load(ImportCandidates.java:90)at org.springframework.boot.autoconfigure.AutoConfigurationImportSelector.getCandidateConfigurations(AutoConfigurationImportSelector.java:180)at org.springframework.boot.autoconfigure.AutoConfigurationImportSelector.getAutoConfigurationEntry(AutoConfigurationImportSelector.java:126)at org.springframework.boot.autoconfigure.AutoConfigurationImportSelector$AutoConfigurationGroup.process(AutoConfigurationImportSelector.java:430)at org.springframework.context.annotation.ConfigurationClassParser$DeferredImportSelectorGrouping.getImports(ConfigurationClassParser.java:796)at org.springframework.context.annotation.ConfigurationClassParser$DeferredImportSelectorGroupingHandler.processGroupImports(ConfigurationClassParser.java:726)at org.springframework.context.annotation.ConfigurationClassParser$DeferredImportSelectorHandler.process(ConfigurationClassParser.java:697)at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:182)at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:415)at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:287)at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:344)at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:115)at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:779)at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:597)- locked <0x12a7> (a java.lang.Object)at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146)at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:733)at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:435)at org.springframework.boot.SpringApplication.run(SpringApplication.java:311)at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301)at org.springframework.boot.SpringApplication.run(SpringApplication.java:1290)at com.dashu.AlibabaApplication.main(AlibabaApplication.java:10)

        调用到这个方法里边：AutoConfigurationImportSelector#getCandidateConfigurations最后查到核心组件的配置文件。这样加载到SpringSecurity的核心文件。最终调用到上边的方法，导致所有的方法都得进行登录认证。

二：默认认证方式的条件限制

1：@ConditionalOnDefaultWebSecurity

        此注解显示了要想使用下面SpringSecurity的默认认证方式是有条件的。

        也就是说，并不是所有的Http请求都必须走默认认证。进入这个注解：

@Target({ ElementType.TYPE, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Conditional(DefaultWebSecurityCondition.class)
public @interface ConditionalOnDefaultWebSecurity {}

        这个注解上边还有一个注解：@Conditional(DefaultWebSecurityCondition.class)

class DefaultWebSecurityCondition extends AllNestedConditions {DefaultWebSecurityCondition() {super(ConfigurationPhase.REGISTER_BEAN);}@ConditionalOnClass({ SecurityFilterChain.class, HttpSecurity.class })static class Classes {}@ConditionalOnMissingBean({ SecurityFilterChain.class })static class Beans {}}

        在这个类当中我们定义了两种鉴权规则。第一种是基于Class，他是基于类作用，也就是说当前在classpath下如果有上述两个class的话，就可以走默认的认证方式。在SpringSecurity中肯定是有的，这也就是在引入SpringSecurity依赖之后就会走默认的配置。

        第二种是基于丢失Bean的情况，如果丢失了，那么我们可以走默认的认证规则了。也就是说，如果没有了SecurityFilterChain这个对象的话，那么就不在使用默认的认证规则了。