获取spring管理的类，获取指定包名下的类

           List<String> ret = new ArrayList<>();
            PathMatchingResourcePatternResolver pathMatchingResourcePatternResolver = new PathMatchingResourcePatternResolver();
            CachingMetadataReaderFactory cachingMetadataReaderFactory = new CachingMetadataReaderFactory();
            org.springframework.core.io.Resource[] resources = pathMatchingResourcePatternResolver.getResources("classpath*:com/peony/common/entity/po/**/*.class");
            ClassLoader loader = ClassLoader.getSystemClassLoader();

            for (org.springframework.core.io.Resource resource : resources) {
                MetadataReader reader = cachingMetadataReaderFactory.getMetadataReader(resource);
                String className = reader.getClassMetadata().getClassName();
                Class aClass = loader.loadClass(className);
                Object o = aClass.newInstance();
                
            }