org.springframework.core.type.classreading.SimpleMetadataReaderFactory#getMetadataReader ( )源码实例Demo

@Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {
	SimpleMetadataReaderFactory metadataReaderFactory = new SimpleMetadataReaderFactory(applicationContext);
	DefaultListableBeanFactory defaultListableBeanFactory = (DefaultListableBeanFactory) beanFactory;
	String resolvedPath = resolvePackageToScan();
	logger.debug("Scanning '{}' for JSON-RPC service interfaces.", resolvedPath);
	try {
		for (Resource resource : applicationContext.getResources(resolvedPath)) {
			if (resource.isReadable()) {
				MetadataReader metadataReader = metadataReaderFactory.getMetadataReader(resource);
				ClassMetadata classMetadata = metadataReader.getClassMetadata();
				AnnotationMetadata annotationMetadata = metadataReader.getAnnotationMetadata();
				String jsonRpcPathAnnotation = JsonRpcService.class.getName();
				if (annotationMetadata.isAnnotated(jsonRpcPathAnnotation)) {
					String className = classMetadata.getClassName();
					String path = (String) annotationMetadata.getAnnotationAttributes(jsonRpcPathAnnotation).get("value");
					logger.debug("Found JSON-RPC service to proxy [{}] on path '{}'.", className, path);
					registerJsonProxyBean(defaultListableBeanFactory, className, path);
				}
			}
		}
	} catch (IOException e) {
		throw new IllegalStateException(format("Cannot scan package '%s' for classes.", resolvedPath), e);
	}
}
 

public static void main(String[] args) throws Exception {
	String locationPattern = "classpath:/org/wallride/domain/*";

	final BootstrapServiceRegistry registry = new BootstrapServiceRegistryBuilder().build();
	final MetadataSources metadataSources = new MetadataSources(registry);
	final StandardServiceRegistryBuilder registryBuilder = new StandardServiceRegistryBuilder(registry);

	registryBuilder.applySetting(AvailableSettings.DIALECT, ExtendedMySQL5InnoDBDialect.class.getCanonicalName());
	registryBuilder.applySetting(AvailableSettings.GLOBALLY_QUOTED_IDENTIFIERS, true);
	registryBuilder.applySetting(AvailableSettings.PHYSICAL_NAMING_STRATEGY, PhysicalNamingStrategySnakeCaseImpl.class);

	final PathMatchingResourcePatternResolver resourcePatternResolver = new PathMatchingResourcePatternResolver();
	final Resource[] resources = resourcePatternResolver.getResources(locationPattern);
	final SimpleMetadataReaderFactory metadataReaderFactory = new SimpleMetadataReaderFactory();
	for (Resource resource : resources) {
		MetadataReader metadataReader = metadataReaderFactory.getMetadataReader(resource);
		AnnotationMetadata metadata = metadataReader.getAnnotationMetadata();
		if (metadata.hasAnnotation(Entity.class.getName())) {
			metadataSources.addAnnotatedClass(Class.forName(metadata.getClassName()));
		}
	}

	final StandardServiceRegistryImpl registryImpl = (StandardServiceRegistryImpl) registryBuilder.build();
	final MetadataBuilder metadataBuilder = metadataSources.getMetadataBuilder(registryImpl);

	new SchemaExport()
			.setHaltOnError(true)
			.setDelimiter(";")
			.create(EnumSet.of(TargetType.STDOUT), metadataBuilder.build());
}
 

public static void main(String[] args) throws IOException {

        // 反射实现
        AnnotationMetadata standardAnnotationMetadata = new StandardAnnotationMetadata(TransactionalService.class);

        SimpleMetadataReaderFactory factory = new SimpleMetadataReaderFactory();

        MetadataReader metadataReader = factory.getMetadataReader(TransactionalService.class.getName());
        // ASM 实现
        AnnotationMetadata annotationMetadata = metadataReader.getAnnotationMetadata();

        int times = 10 * 10000; // 10 万次

        testAnnotationMetadataPerformance(standardAnnotationMetadata, times);
        testAnnotationMetadataPerformance(annotationMetadata, times);

        times = 100 * 10000;    // 100 万次

        testAnnotationMetadataPerformance(standardAnnotationMetadata, times);
        testAnnotationMetadataPerformance(annotationMetadata, times);

        times = 1000 * 10000;   // 1000 万次

        testAnnotationMetadataPerformance(standardAnnotationMetadata, times);
        testAnnotationMetadataPerformance(annotationMetadata, times);

        times = 10000 * 10000; // 1 亿次

        testAnnotationMetadataPerformance(standardAnnotationMetadata, times);
        testAnnotationMetadataPerformance(annotationMetadata, times);
    }