\u5148\u629b\u51fa\u4e2a\u95ee\u9898\uff1aSpringBoot \u5141\u8bb8\u901a\u8fc7\u6ce8\u89e3\u6839\u636e\u67d0\u4e2a\u7c7b\u662f\u5426\u5b58\u5728\u6765\u51b3\u5b9a\u914d\u7f6e\uff0c\u5982<\/p>\n
@Bean\n@ConditionalOnClass(value = HikariDataSource.class)\npublic DataSource hikariDataSource() {\n return new HikariDataSource();\n}\n\n@Bean\n@ConditionalOnClass(value = BasicDataSource.class)\npublic DataSource basicDataSource() {\n return new BasicDataSource();\n}\n<\/code><\/pre>\n\u6211\u4eec\u4e5f\u77e5\u9053 ClassLoader<\/code> \u52a0\u8f7d\u4e00\u4e2a\u7c7b\u65f6\uff0c\u5982\u679c\u8fd9\u4e2a\u7c7b\u6216\u8fd9\u4e2a\u7c7b\u4f9d\u8d56\u7684\u7c7b\u627e\u4e0d\u5230\u5219\u4f1a\u629b\u51fa ClassNotFoundException<\/code> \u3002<\/p>\nSpring \u662f\u5982\u4f55\u5b9e\u73b0\u8fd9\u6837\u7684\u6761\u4ef6\u52a0\u8f7d\u800c\u4e0d\u4f1a\u629b\u51fa ClassNotFoundException<\/code> \u5f02\u5e38\uff1f<\/p>\n<\/p>\n
2. Spring \u89e3\u6790\u914d\u7f6e\u7c7b\u7684\u8fc7\u7a0b<\/h1>\n
\u5728\u7b2c\u4e00\u7bc7<\/a>\u5df2\u7ecf\u4ecb\u7ecd\u8fc7 ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry<\/code> \u4f1a\u6ce8\u518c\u6240\u6709\u7684 Bean \u5b9a\u4e49\u3002\u73b0\u5728\u6765\u4ed4\u7ec6\u770b\u770b\u8fd9\u4e2a\u8fc7\u7a0b\u3002<\/p>\npublic void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) {\n int registryId = System.identityHashCode(registry);\n if (this.registriesPostProcessed.contains(registryId)) {\n throw new IllegalStateException(\n \"postProcessBeanDefinitionRegistry already called on this post-processor against \" + registry);\n }\n if (this.factoriesPostProcessed.contains(registryId)) {\n throw new IllegalStateException(\n \"postProcessBeanFactory already called on this post-processor against \" + registry);\n }\n this.registriesPostProcessed.add(registryId);\n\n processConfigBeanDefinitions(registry);\n}\n<\/code><\/pre>\n\u8fd9\u4e2a\u65b9\u6cd5\u4e3b\u8981\u662f\u505a\u4e86\u9632\u6b62\u91cd\u590d\u6ce8\u518c\u7684\u5904\u7406\uff0c\u5177\u4f53\u7684\u6ce8\u518c\u903b\u8f91\u5728 processConfigBeanDefinitions(registry)<\/code> \u3002<\/p>\npublic void processConfigBeanDefinitions(BeanDefinitionRegistry registry) {\n List<BeanDefinitionHolder> configCandidates = new ArrayList<BeanDefinitionHolder>();\n String[] candidateNames = registry.getBeanDefinitionNames();\n\n \/\/ \u9996\u5148\u4ece registry \u627e\u51fa\u5df2\u7ecf\u6ce8\u518c\u7684\u672a\u5904\u7406\u7684\u914d\u7f6e\u7c7b\u7684\u5b9a\u4e49\u4f5c\u4e3a\u914d\u7f6e\u7c7b\u5019\u9009\n for (String beanName : candidateNames) {\n BeanDefinition beanDef = registry.getBeanDefinition(beanName);\n if (ConfigurationClassUtils.isFullConfigurationClass(beanDef) ||\n ConfigurationClassUtils.isLiteConfigurationClass(beanDef)) {\n if (logger.isDebugEnabled()) {\n logger.debug(\"Bean definition has already been processed as a configuration class: \" + beanDef);\n }\n }\n else if (ConfigurationClassUtils.checkConfigurationClassCandidate(beanDef, this.metadataReaderFactory)) {\n configCandidates.add(new BeanDefinitionHolder(beanDef, beanName));\n }\n }\n\n \/\/ Return immediately if no @Configuration classes were found\n if (configCandidates.isEmpty()) {\n return;\n }\n\n \/\/ \u5bf9\u914d\u7f6e\u7c7b\u5019\u9009\u8fdb\u884c\u6392\u5e8f\uff0c\u4ee5\u6ee1\u8db3\u4f9d\u8d56\u914d\u7f6e\u4f9d\u8d56\u987a\u5e8f\n \/\/ Sort by previously determined @Order value, if applicable\n Collections.sort(configCandidates, new Comparator<BeanDefinitionHolder>() {\n @Override\n public int compare(BeanDefinitionHolder bd1, BeanDefinitionHolder bd2) {\n int i1 = ConfigurationClassUtils.getOrder(bd1.getBeanDefinition());\n int i2 = ConfigurationClassUtils.getOrder(bd2.getBeanDefinition());\n return (i1 < i2) ? -1 : (i1 > i2) ? 1 : 0;\n }\n });\n\n \/\/ \u627e\u51fa beanName \u7684\u751f\u6210\u5668\n \/\/ Detect any custom bean name generation strategy supplied through the enclosing application context\n SingletonBeanRegistry sbr = null;\n if (registry instanceof SingletonBeanRegistry) {\n sbr = (SingletonBeanRegistry) registry;\n if (!this.localBeanNameGeneratorSet && sbr.containsSingleton(CONFIGURATION_BEAN_NAME_GENERATOR)) {\n BeanNameGenerator generator = (BeanNameGenerator) sbr.getSingleton(CONFIGURATION_BEAN_NAME_GENERATOR);\n this.componentScanBeanNameGenerator = generator;\n this.importBeanNameGenerator = generator;\n }\n }\n\n \/\/ Parse each @Configuration class\n \/\/ \u521b\u5efa ConfigurationClassParser \u6765\u89e3\u6790\u5019\u9009\u914d\u7f6e\u7c7b\u5b9a\u4e49\n ConfigurationClassParser parser = new ConfigurationClassParser(\n this.metadataReaderFactory, this.problemReporter, this.environment,\n this.resourceLoader, this.componentScanBeanNameGenerator, registry);\n\n \/\/ \u5f53\u524d\u5f85\u89e3\u6790\u7684\u5019\u9009\u914d\u7f6e\u7c7b\u5b9a\u4e49\n Set<BeanDefinitionHolder> candidates = new LinkedHashSet<BeanDefinitionHolder>(configCandidates);\n\n \/\/ \u5f53\u524d\u5df2\u89e3\u6790\u7684\u914d\u7f6e\u7c7b\n Set<ConfigurationClass> alreadyParsed = new HashSet<ConfigurationClass>(configCandidates.size());\n do {\n \/\/ \u89e3\u6790\u5f53\u524d\u5019\u9009\u96c6\u91cc\u7684\u6240\u6709\u914d\u7f6e\u7c7b\u5b9a\u4e49\n parser.parse(candidates);\n\n \/\/ \u9a8c\u8bc1\u89e3\u6790\u7684\u7ed3\u679c\n parser.validate();\n\n \/\/ \u4ece\u89e3\u6790\u83b7\u53d6\u89e3\u6790\u5f97\u5230\u7684\u6240\u6709\u914d\u7f6e\u7c7b\n Set<ConfigurationClass> configClasses = new LinkedHashSet<ConfigurationClass>(parser.getConfigurationClasses());\n\n \/\/ \u79fb\u9664\u5df2\u7ecf\u5904\u7406\u8fc7\u7684\u914d\u7f6e\u7c7b\uff0c\u56e0\u4e3a\u4e0b\u9762\u8981\u8fdb\u884c\u6ce8\u518c\uff0c\u9632\u6b62\u91cd\u590d\u6ce8\u518c\n configClasses.removeAll(alreadyParsed);\n\n \/\/ \u521b\u5efa ConfigurationClassBeanDefinitionReader\uff0c\u7528\u4e8e\u6ce8\u518c\u914d\u7f6e\u7c7b\n \/\/ reader \u7684\u521b\u5efa\u5e94\u8be5\u662f\u53ef\u4ee5\u653e\u5230\u5faa\u73af\u5916\u7684\n \/\/ Read the model and create bean definitions based on its content\n if (this.reader == null) {\n this.reader = new ConfigurationClassBeanDefinitionReader(\n registry, this.sourceExtractor, this.resourceLoader, this.environment,\n this.importBeanNameGenerator, parser.getImportRegistry());\n }\n\n \/\/ \u6ce8\u518c\u914d\u7f6e\u7c7b\n this.reader.loadBeanDefinitions(configClasses);\n\n \/\/ \u628a\u672c\u8f6e\u5904\u7406\u5b8c\u7684\u914d\u7f6e\u7c7b\u52a0\u5230\u5df2\u5904\u7406\u96c6\u5408\n alreadyParsed.addAll(configClasses);\n\n \/\/ \u6e05\u9664\u5df2\u5904\u7406\u7684\u5019\u9009\u96c6\uff0c\u590d\u7528\u8fd9\u4e2a\u96c6\u5408\n candidates.clear();\n\n \/\/ \u4ece registry \u627e\u51fa\u65b0\u52a0\u5165\u3001\u672a\u5904\u7406\u8fc7\u7684\u914d\u7f6e\u7c7b\u5b9a\u4e49\uff0c\u52a0\u5165\u5f53\u524d\u5019\u9009\u96c6\n if (registry.getBeanDefinitionCount() > candidateNames.length) {\n String[] newCandidateNames = registry.getBeanDefinitionNames();\n Set<String> oldCandidateNames = new HashSet<String>(Arrays.asList(candidateNames));\n Set<String> alreadyParsedClasses = new HashSet<String>();\n for (ConfigurationClass configurationClass : alreadyParsed) {\n alreadyParsedClasses.add(configurationClass.getMetadata().getClassName());\n }\n for (String candidateName : newCandidateNames) {\n if (!oldCandidateNames.contains(candidateName)) { \/\/ \u8fc7\u6ee4\u51fa\u65b0\u52a0\u5165\u7684\n BeanDefinition bd = registry.getBeanDefinition(candidateName);\n if (ConfigurationClassUtils.checkConfigurationClassCandidate(bd, this.metadataReaderFactory) &&\n !alreadyParsedClasses.contains(bd.getBeanClassName())) { \/\/ \u627e\u51fa\u672a\u5904\u7406\u8fc7\u7684\n candidates.add(new BeanDefinitionHolder(bd, candidateName));\n }\n }\n }\n candidateNames = newCandidateNames;\n }\n } while (!candidates.isEmpty()); \/\/ \u5982\u679c\u5f53\u524d\u5019\u9009\u96c6\u4e0d\u4e3a\u7a7a\u5219\u7ee7\u7eed\u4e0b\u4e00\u8f6e\u5904\u7406\n\n \/\/ \u81f3\u6b64\uff0c\u901a\u8fc7 Java \u7c7b\u914d\u7f6e\u7684 bean \u5b9a\u4e49\u90fd\u52a0\u8f7d\u5e76\u6ce8\u518c\u5230\u5bb9\u5668\n\n \/\/ Register the ImportRegistry as a bean in order to support ImportAware @Configuration classes\n if (sbr != null) {\n if (!sbr.containsSingleton(IMPORT_REGISTRY_BEAN_NAME)) {\n sbr.registerSingleton(IMPORT_REGISTRY_BEAN_NAME, parser.getImportRegistry());\n }\n }\n\n if (this.metadataReaderFactory instanceof CachingMetadataReaderFactory) {\n ((CachingMetadataReaderFactory) this.metadataReaderFactory).clearCache();\n }\n}\n<\/code><\/pre>\n\u4e0a\u8ff0\u65b9\u6cd5\u5e76\u672a\u6d89\u53ca\u67d0\u4e2a\u914d\u7f6e\u7c7b\u5b9a\u4e49\u5982\u4f55\u89e3\u6790\u5f97\u5230\u914d\u7f6e\u7c7b\u3001\u6ce8\u518c\u914d\u7f6e\u7c7b\u5b9a\u4e49\u7684\u7ec6\u8282\u8fd9\u4e00\u5c42\u7684\u903b\u8f91\u5982\u4e0b\uff1a
\n1. \u4ece registry<\/code> \u6536\u96c6\u914d\u7f6e\u7c7b\u5b9a\u4e49\u653e\u5230 Set<BeanDefinitionHolder> candidates<\/code> \u4f5c\u4e3a\u5904\u7406\u7684\u5f00\u59cb\u6e90\uff1b
\n2. \u521b\u5efa ConfigurationClassParser parser<\/code> \u7528\u4e8e\u89e3\u6790\u65b0\u7684\u914d\u7f6e\u7c7b\u5b9a\u4e49\u548c ConfigurationClassBeanDefinitionReader reader<\/code> \u7528\u4e8e\u6ce8\u518c\u65b0\u7684\u914d\u7f6e\u7c7b\u5b9a\u4e49\uff1b
\n3. \u521d\u59cb\u5316\u5df2\u89e3\u6790\u96c6\u5408 alreadyParsed<\/code>\uff1b
\n4. \u7528 parser<\/code> \u89e3\u6790\u5019\u9009\u96c6 candidates<\/code>\uff0c\u8fdb\u884c\u9a8c\u8bc1\uff1b
\n5. \u5f97\u5230\u89e3\u6790\u7ed3\u679c Set<ConfigurationClass> configClasses<\/code>\uff0c\u79fb\u9664\u5df2\u7ecf\u5904\u7406\u8fc7\u7684 Set<ConfigurationClass> alreadyParsed<\/code> \uff1b
\n6. \u7528 reader<\/code> \u628a\u6536\u96c6\u5230\u7684\u914d\u7f6e\u7c7b\u96c6\u5408 configClasses<\/code> \u6ce8\u518c\u5230 registry<\/code>\uff1b
\n7. \u628a configClasses<\/code> \u52a0\u5165\u5df2\u89e3\u6790\u96c6\u5408 alreadyParsed<\/code>;
\n8. \u6e05\u7a7a\u5019\u9009\u96c6 candidates<\/code>\uff0c\u91cd\u65b0\u6536\u96c6\u5019\u9009\u96c6 candidates<\/code>\uff1b
\n9. \u5982\u679c\u6536\u96c6\u5230\u7684\u5019\u9009\u96c6 candidates<\/code> \u4e0d\u4e3a\u7a7a\uff0c\u7ee7\u7eed\u8dcc\u4ee3\u6b65\u9aa4 4 \u3002<\/p>\n\u73b0\u5728\u6765\u770b\u5982\u4f55\u89e3\u6790\u5019\u9009\u96c6\uff0cConfigurationClassParser.parse(Set<BeanDefinitionHolder> configCandidates)<\/code> \uff1a<\/p>\npublic void parse(Set<BeanDefinitionHolder> configCandidates) {\n this.deferredImportSelectors = new LinkedList<DeferredImportSelectorHolder>();\n\n for (BeanDefinitionHolder holder : configCandidates) {\n BeanDefinition bd = holder.getBeanDefinition();\n try {\n if (bd instanceof AnnotatedBeanDefinition) {\/\/ \u57fa\u4e8e Java \u7c7b\u914d\u7f6e\u7684\u90fd\u662f\u8d70\u8fd9\u91cc\n parse(((AnnotatedBeanDefinition) bd).getMetadata(), holder.getBeanName());\n }\n else if (bd instanceof AbstractBeanDefinition && ((AbstractBeanDefinition) bd).hasBeanClass()) {\n parse(((AbstractBeanDefinition) bd).getBeanClass(), holder.getBeanName());\n }\n else {\n parse(bd.getBeanClassName(), holder.getBeanName());\n }\n }\n catch (BeanDefinitionStoreException ex) {\n throw ex;\n }\n catch (Throwable ex) {\n throw new BeanDefinitionStoreException(\n \"Failed to parse configuration class [\" + bd.getBeanClassName() + \"]\", ex);\n }\n }\n\n processDeferredImportSelectors();\n}\n\n\nprotected void processConfigurationClass(ConfigurationClass configClass) throws IOException {\n \/\/ ....\u5220\u6389\u4e86\u9632\u6b62\u91cd\u590d\u5904\u7406\u7684\u903b\u8f91\n\n \/\/ SourceClass \u662f\u4e00\u4e2a\u7b80\u5355\u7684\u5305\u88c5\uff0c\u5141\u8bb8\u88ab\u6ce8\u89e3\u7684\u6e90\u7c7b\u4ee5\u7edf\u4e00\u7684\u65b9\u5f0f\u8fdb\u884c\u5904\u7406\uff0c\u800c\u4e0d\u7ba1\u5b83\u4eec\u662f\u5982\u4f55\u52a0\u8f7d\u7684\n\n \/\/ \u9012\u5f52\u5904\u7406\u914d\u7f6e\u7c7b\u548c\u5b83\u7684\u8d85\u7c7b\n SourceClass sourceClass = asSourceClass(configClass);\n do {\n \/\/ \u5904\u7406\u7ed9\u5b9a\u7684\u914d\u7f6e\u7c7b\uff0c\u5982\u679c\u5b83\u6709\u975e Object \u7684\u7236\u7c7b\uff0c\u5219\u8fd4\u56de\u5176\u7236\u7c7b\uff0c\u9012\u5f52\u5904\u7406\n sourceClass = doProcessConfigurationClass(configClass, sourceClass);\n }\n while (sourceClass != null);\n\n this.configurationClasses.put(configClass, configClass);\n}\n\nprotected final SourceClass doProcessConfigurationClass(ConfigurationClass configClass, SourceClass sourceClass) throws IOException {\n\n \/\/ \u9996\u5148\u9012\u5f52\u5904\u7406\u5185\u90e8\u5d4c\u5957\u7c7b\n processMemberClasses(configClass, sourceClass);\n\n \/\/ \u5904\u7406 @PropertySource \u6ce8\u89e3\uff0c\u628a\u8d44\u6e90\u6587\u4ef6\u52a0\u8f7d\u5230 environment \u91cc\n for (AnnotationAttributes propertySource : AnnotationConfigUtils.attributesForRepeatable(\n sourceClass.getMetadata(), PropertySources.class,\n org.springframework.context.annotation.PropertySource.class)) {\n if (this.environment instanceof ConfigurableEnvironment) {\n processPropertySource(propertySource);\n } else {\n logger.warn(\"Ignoring @PropertySource annotation on [\" + sourceClass.getMetadata().getClassName() +\n \"]. Reason: Environment must implement ConfigurableEnvironment\");\n }\n }\n\n \/\/ \u5904\u7406 @ComponentScan \u6ce8\u89e3\uff0c\u5982\u679c\u6709\uff0c\u7acb\u5373\u6267\u884c\u626b\u63cf\n Set<AnnotationAttributes> componentScans = AnnotationConfigUtils.attributesForRepeatable(\n sourceClass.getMetadata(), ComponentScans.class, ComponentScan.class);\n if (!componentScans.isEmpty() &&\n !this.conditionEvaluator.shouldSkip(sourceClass.getMetadata(), ConfigurationPhase.REGISTER_BEAN)) {\n for (AnnotationAttributes componentScan : componentScans) {\n \/\/ \u5982\u679c\u914d\u7f6e\u7c7b\u6709 @ComponentScan \u6ce8\u89e3\uff0c\u7acb\u5373\u6267\u884c\u626b\u63cf\n Set<BeanDefinitionHolder> scannedBeanDefinitions =\n this.componentScanParser.parse(componentScan, sourceClass.getMetadata().getClassName());\n \/\/ \u68c0\u67e5\u626b\u63cf\u5230\u7684\u5b9a\u4e49\u91cc\u662f\u5426\u6709\u66f4\u591a\u7684\u914d\u7f6e\u7c7b\uff0c\u6709\u5219\u9012\u5f52 parse\n for (BeanDefinitionHolder holder : scannedBeanDefinitions) {\n BeanDefinition bdCand = holder.getBeanDefinition().getOriginatingBeanDefinition();\n if (bdCand == null) {\n bdCand = holder.getBeanDefinition();\n }\n if (ConfigurationClassUtils.checkConfigurationClassCandidate(bdCand, this.metadataReaderFactory)) {\n parse(bdCand.getBeanClassName(), holder.getBeanName());\n }\n }\n }\n }\n\n \/\/ \u5904\u7406 @Import \u6ce8\u89e3\n processImports(configClass, sourceClass, getImports(sourceClass), true);\n\n \/\/ \u5904\u7406 @ImportResource \u6ce8\u89e3\n if (sourceClass.getMetadata().isAnnotated(ImportResource.class.getName())) {\n AnnotationAttributes importResource =\n AnnotationConfigUtils.attributesFor(sourceClass.getMetadata(), ImportResource.class);\n String[] resources = importResource.getStringArray(\"locations\");\n Class<? extends BeanDefinitionReader> readerClass = importResource.getClass(\"reader\");\n for (String resource : resources) {\n String resolvedResource = this.environment.resolveRequiredPlaceholders(resource);\n configClass.addImportedResource(resolvedResource, readerClass);\n }\n }\n\n \/\/ \u5904\u7406 @Bean \u6ce8\u89e3\u7684\u65b9\u6cd5\n Set<MethodMetadata> beanMethods = retrieveBeanMethodMetadata(sourceClass);\n for (MethodMetadata methodMetadata : beanMethods) {\n configClass.addBeanMethod(new BeanMethod(methodMetadata, configClass));\n }\n\n \/\/ \u5904\u7406\u63a5\u53e3\u7684\u9ed8\u8ba4\u65b9\u6cd5\n processInterfaces(configClass, sourceClass);\n\n \/\/ \u5982\u679c\u6709\uff0c\u5904\u7406\u7236\u7c7b\n if (sourceClass.getMetadata().hasSuperClass()) {\n String superclass = sourceClass.getMetadata().getSuperClassName();\n if (!superclass.startsWith(\"java\") && !this.knownSuperclasses.containsKey(superclass)) {\n this.knownSuperclasses.put(superclass, configClass);\n \/\/ Superclass found, return its annotation metadata and recurse\n return sourceClass.getSuperClass();\n }\n }\n\n \/\/ \u6ca1\u6709\u7236\u7c7b\uff0c\u5904\u7406\u5b8c\u6210\n return null;\n}\n<\/code><\/pre>\n\u89e3\u6790\u4e00\u4e2a\u914d\u7f6e\u7c7b\u7684\u5927\u81f4\u8fc7\u7a0b\uff1a<\/p>\n
\n- \u9012\u5f52\u5904\u7406\u6240\u6709\u5d4c\u5957\u7c7b\uff1b<\/li>\n
- \u5904\u7406\u6e90\u7c7b\u4e0a
@PropertySource<\/code> \u6ce8\u89e3\uff1b<\/li>\n- \u5904\u7406
@ComponentScan<\/code> \u6ce8\u89e3\uff1b<\/li>\n- \u5904\u7406
@Import<\/code> \u6ce8\u89e3\uff0c\u901a\u8fc7\u81ea\u5b9a\u4e49\u7684 ImportSelector\/ImportBeanDefinitionRegistrar<\/code> \u63a5\u53e3\u5b9e\u73b0\u6765\u52a0\u8f7dbean\u5b9a\u4e49\uff1b<\/li>\n- \u5904\u7406
@ImportResource<\/code> \u6ce8\u89e3\uff1b<\/li>\n- \u5904\u7406\u6240\u6709\u6709
@Bean<\/code> \u6ce8\u89e3\u7684\u65b9\u6cd5\uff0c\u65b9\u6cd5\u7684\u4fe1\u606f\u5c01\u88c5\u5728 MethodMetadata<\/code>\uff0c\u4e0e\u6240\u5728\u7684\u914d\u7f6e\u7c7b\u4e00\u8d77\u5c01\u88c5\u6210 BeanMethod<\/code> \u6dfb\u52a0\u5230\u914d\u7f6e\u7c7b\u7684 beanMethods<\/code> \u96c6\u5408\u91cc\uff1b<\/li>\n- \u9012\u5f52\u5904\u7406\u6240\u5b9e\u73b0\u7684 interfaces \u4e0a\u7684\u9ed8\u8ba4\u65b9\u6cd5\uff1b<\/li>\n
- \u5982\u679c\u975e Object\u3001\u975e java \u81ea\u5e26\u7c7b\u7684\u7236\u7c7b\uff0c\u5219\u8fd4\u56de\u8fdb\u884c\u9012\u5f52\u5904\u7406\uff1b<\/li>\n<\/ol>\n
\u4e0a\u9762\u7684\u89e3\u6790\u8fc7\u7a0b\u4e2d\u6709\u4e2a\u5f88\u91cd\u8981\u7684\u89d2\u8272\u662f SourceClass<\/code>\uff0c\u8868\u793a SpringBoot \u81ea\u5df1\u89e3\u6790\u5230\u7684\u6e90\u6587\u4ef6\u4fe1\u606f\u3002<\/p>\n\/\/ SourceClass \u662f\u4e00\u4e2a\u7b80\u5355\u7684\u5305\u88c5\uff0c\u5141\u8bb8\u88ab\u6ce8\u89e3\u7684\u6e90\u7c7b\u4ee5\u7edf\u4e00\u7684\u65b9\u5f0f\u8fdb\u884c\u5904\u7406\uff0c\u800c\u4e0d\u7ba1\u5b83\u4eec\u662f\u5982\u4f55\u52a0\u8f7d\u7684\n\n\/\/ \u9012\u5f52\u5904\u7406\u914d\u7f6e\u7c7b\u548c\u5b83\u7684\u8d85\u7c7b\nSourceClass sourceClass = asSourceClass(configClass);\ndo {\n \/\/ \u5904\u7406\u7ed9\u5b9a\u7684\u914d\u7f6e\u7c7b\uff0c\u5982\u679c\u5b83\u6709\u975e Object \u7684\u7236\u7c7b\uff0c\u5219\u8fd4\u56de\u5176\u7236\u7c7b\uff0c\u9012\u5f52\u5904\u7406\n sourceClass = doProcessConfigurationClass(configClass, sourceClass);\n}\nwhile (sourceClass != null);\n<\/code><\/pre>\n\u5728\u4e0a\u8ff0\u7684\u9012\u5f52\u5904\u7406\u8fc7\u7a0b\u4e2d\uff0csourceClass \u4e00\u5f00\u59cb\u662f\u914d\u7f6e\u7c7b\u672c\u8eab\u5bf9\u5e94\u7684\u6e90\u7c7b\u7684\u4fe1\u606f\uff0c\u540e\u7eed\u662f\u5176\u7236\u7c7b\u7684\u6e90\u7c7b\u4fe1\u606f\u3002<\/p>\n
SourceClass<\/h2>\n
SourceClass \u4e0e Class \u5565\u533a\u522b\uff1f\u4e3a\u4ec0\u4e48\u9700\u8981\u5b83\uff1f<\/p>\n
\u4ece\u4e0a\u9762\u4ee3\u7801\u7684 SourceClass sourceClass = asSourceClass(configClass);<\/code> \u5f00\u59cb\u770b\uff1a<\/p>\nSourceClass asSourceClass(String className) throws IOException {\n if (className.startsWith(\"java\")) {\n \/\/ \u5bf9\u4e8e\u6838\u5fc3Java\u7c7b\u4e0d\u4f7f\u7528ASM\uff0c\u56e0\u4e3a\u80af\u5b9a\u5b58\u5728\u7684\uff0c\u76f4\u63a5\u52a0\u8f7d\n try {\n return new SourceClass(this.resourceLoader.getClassLoader().loadClass(className));\n } catch (ClassNotFoundException ex) {\n throw new NestedIOException(\"Failed to load class [\" + className + \"]\", ex);\n }\n }\n return new SourceClass(this.metadataReaderFactory.getMetadataReader(className));\n}\n<\/code><\/pre>\nmetadataReaderFactory \u7528\u5b8c\u6574\u7c7b\u540d\u6784\u9020\u4e00\u4e2a Resource\uff0c\u7136\u540e\u8fd9\u4e2a Resource \u548c ClassLoader \u6765\u6784\u9020\u4e00\u4e2a SimpleMetadataReader\u3002SimpleMetadataReader \u901a\u8fc7 ClassReader \u6765\u8bfb\u53d6\u8fd9\u4e2a\u7c7b\u7684\u5b57\u8282\u7801\u6587\u4ef6\uff0c\u518d\u901a\u8fc7 ASM \u5de5\u5177 AnnotationMetadataReadingVisitor \u8fdb\u884c\u89e3\u6790\uff0c\u5f97\u5230\u5173\u4e8e\u8fd9\u4e2a\u7c7b\u7684\u5143\u6570\u636e\u3002\u8fd9\u4e2a\u8fc7\u7a0b\u7ed5\u8fc7\u4e86JDK \u7684\u7c7b\u52a0\u8f7d\u673a\u5236\uff0c\u4e5f\u5c31\u907f\u514d\u4e86\u4e00\u5f00\u59cb\u90a3\u4e2a\u53ef\u80fd\u51fa\u73b0\u7c7b\u627e\u4e0d\u5230\u7684\u95ee\u9898\u3002<\/p>\n
\u6709\u5174\u8da3\u7684\u53ef\u4ee5\u7ee7\u7eed\u770b\u4e0b SimpleMetadataReader\uff0cMetadataReader<\/code> \u7684\u552f\u4e00\u5b9e\u73b0\u7c7b\uff1a<\/p>\nfinal class SimpleMetadataReader implements MetadataReader {\n private final Resource resource;\n private final ClassMetadata classMetadata;\n private final AnnotationMetadata annotationMetadata;\n\n SimpleMetadataReader(Resource resource, ClassLoader classLoader) throws IOException {\n InputStream is = new BufferedInputStream(resource.getInputStream());\n ClassReader classReader;\n try {\n classReader = new ClassReader(is);\n } catch (IllegalArgumentException ex) {\n throw new NestedIOException(\"ASM ClassReader failed to parse class file - \" +\n \"probably due to a new Java class file version that isn't supported yet: \" + resource, ex);\n } finally {\n is.close();\n }\n\n AnnotationMetadataReadingVisitor visitor = new AnnotationMetadataReadingVisitor(classLoader);\n classReader.accept(visitor, ClassReader.SKIP_DEBUG);\n\n this.annotationMetadata = visitor;\n \/\/ (since AnnotationMetadataReadingVisitor extends ClassMetadataReadingVisitor)\n this.classMetadata = visitor;\n this.resource = resource;\n }\n \/\/ \u7701\u7565\u5176\u4ed6\u4ee3\u7801\n}\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"1. \u4e00\u4e2a Spring \u52a0\u8f7d\u7c7b\u7684\u95ee\u9898 \u5148\u629b\u51fa\u4e2a\u95ee\u9898\uff1aSpringBoot \u5141\u8bb8 … \u7ee7\u7eed\u9605\u8bfb