Spring下扫描特定包下特定注解的类并动态注册bean

摘要：动态注册扫描提取包路径下，标记了注解的类出现异常注册检查当前扫描到的类是否含有任何一个指定的注解标记过滤匹配类型时出错

public class SpringContextHolder implements ApplicationContextAware{

    private static ApplicationContext context;
    private static BeanDefinitionRegistry beanDefinitonRegistry;

    public static ApplicationContext getApplicationContext() {
        return context;
    }
    public static Object getBean(String name){
        return context.getBean(name);
    }
    public static  T getBean(Class clz){
        return context.getBean(clz);
    }
    public static  T getBean(String name , Class clz){
        return context.getBean(name, clz);
    }
    @Override
    public void setApplicationContext(ApplicationContext ac)
            throws BeansException {
        context = ac;
      //DefaultListableBeanFactory acf = (DefaultListableBeanFactory) app.getAutowireCapableBeanFactory();
      ConfigurableApplicationContext configurableApplicationContext = (ConfigurableApplicationContext) context;
        beanDefinitonRegistry = (BeanDefinitionRegistry) configurableApplicationContext
          .getBeanFactory();
    }
    /**
     * 动态注册bean
     * @param beanName
     * @param beanDefinition
     */
    public synchronized static void registerBean(String beanName, BeanDefinition beanDefinition){
        //DefaultListableBeanFactory beanDefinitonRegistry = (DefaultListableBeanFactory) app.getAutowireCapableBeanFactory();
        if(!beanDefinitonRegistry.containsBeanDefinition(beanName)){
          beanDefinitonRegistry.registerBeanDefinition(beanName, beanDefinition);
        }
    }
    public static void registerBean(BeanDefinition beanDefinition){
        //DefaultListableBeanFactory beanDefinitonRegistry = (DefaultListableBeanFactory) app.getAutowireCapableBeanFactory();
        String simpleNameString=beanDefinition.getBeanClassName();
        if(simpleNameString.contains(".")){
            simpleNameString=simpleNameString.substring(simpleNameString.lastIndexOf(".")+1);
        }
        simpleNameString=StringUtil.lowerFirstChar(simpleNameString);
        registerBean(simpleNameString,beanDefinition);
    }
    public static BeanDefinitionBuilder getBeanDefinitionBuilder(Class clazz){
        return BeanDefinitionBuilder.genericBeanDefinition(clazz);
    }

}

public class ClassScanner {
    private final Logger logger = LoggerFactory.getLogger(getClass());
    private static final String RESOURCE_PATTERN = "**/%s/**/*.class";
    private ResourcePatternResolver resourcePatternResolver = new PathMatchingResourcePatternResolver();

    public ClassScanner(){
    }

    @SafeVarargs
    public final Set> scan(String[] confPkgs, Class... annotationTags){
        Set> resClazzSet = new HashSet<>();
        List typeFilters = new LinkedList<>();
        if (ArrayUtils.isNotEmpty(annotationTags)){
            for (Class annotation : annotationTags) {
                typeFilters.add(new AnnotationTypeFilter(annotation, false));
            }
        }
        if (ArrayUtils.isNotEmpty(confPkgs)) {
            for (String pkg : confPkgs) {
                String pattern = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX  + String.format(RESOURCE_PATTERN,ClassUtils.convertClassNameToResourcePath(pkg));
                try {
                    Resource[] resources = this.resourcePatternResolver.getResources(pattern);
                    MetadataReaderFactory readerFactory = new CachingMetadataReaderFactory(this.resourcePatternResolver);
                    for (Resource resource : resources) {
                        if (resource.isReadable()) {
                            MetadataReader reader = readerFactory.getMetadataReader(resource);
                            String className = reader.getClassMetadata().getClassName();
                            if (ifMatchesEntityType(reader, readerFactory,typeFilters)) {
                                Class curClass = Thread.currentThread().getContextClassLoader().loadClass(className);
                                resClazzSet.add(curClass);
                            }
                        }
                    }
                } catch (Exception e) {
                    logger.error("扫描提取[{}]包路径下，标记了注解[{}]的类出现异常", pattern,StringUtils.join(typeFilters,","));
                }
            }
        }
        return resClazzSet;
    }

    /**
     * 注册Bean
     * @param classList
     */
    public void regist(List> classList){
        for(Class clzz:classList){
            SpringContextHolder.registerBean(SpringContextHolder.getBeanDefinitionBuilder(clzz).getBeanDefinition());
        }
    }

    /**
     * 检查当前扫描到的类是否含有任何一个指定的注解标记
     * @param reader
     * @param readerFactory
     * @return ture/false
     */
    private boolean ifMatchesEntityType(MetadataReader reader, MetadataReaderFactory readerFactory,List typeFilters) {
        if (!CollectionUtils.isEmpty(typeFilters)) {
            for (TypeFilter filter : typeFilters) {
                try {
                    if (filter.match(reader, readerFactory)) {
                        return true;
                    }
                } catch (IOException e) {
                    logger.error("过滤匹配类型时出错 {}",e.getMessage());
                }
            }
        }
        return false;
    }
}