利用spring的扫描工具类,扫描自定义的注解

最新推荐文章于 2024-08-03 19:46:32 发布

转载最新推荐文章于 2024-08-03 19:46:32 发布 · 3.3k 阅读

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CC 4.0 BY-SA版权

原文链接：https://my.oschina.net/lmxy1990/blog/3037703

文章标签：

#java

本文介绍了一个用于Java项目的实用工具类ReadAnnotationUtils，它能够根据包路径获取指定注解的所有类信息。通过ResourcePatternResolver和SimpleMetadataReaderFactory等Spring核心组件，该工具实现了对类路径下所有带有特定注解的类进行扫描和收集。

为什么80%的码农都做不了架构师？>>>

public class ReadAnnotationUtils {

    private static final PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
    private static final SimpleMetadataReaderFactory register = new SimpleMetadataReaderFactory();
    private static final StandardEnvironment environment = new StandardEnvironment();


    /**
     * 根据包路径,获取Class的资源路径
     *
     * @param packagePath
     * @return
     */
    public static String getResourcePath(String packagePath) {
        if (StringUtils.isEmpty(packagePath)) return "";
        String resourcePath = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX
                + ClassUtils.convertClassNameToResourcePath(environment.resolveRequiredPlaceholders(packagePath))
                + '/' + "**/*.class";
        return resourcePath;
    }

    /**
     * 获取指定路径下的类
     *
     * @param pkgPath
     * @param annoClazz
     * @return
     */
    public static Set<Class> getClazzFromAnnotation(String pkgPath, Class<? extends Annotation> annoClazz) {
        //获取spring的包路径
        String pathPackage = getResourcePath(pkgPath);

        Set<Class> paths = new HashSet<>();
        Resource[] resources = new Resource[0];
        try {
            //加载路径
            resources = resolver.getResources(pathPackage);
        } catch (IOException e) {
            //异常处理
            return new HashSet<>();
        }
        for (int i = 0; i < resources.length; i++) {
            Resource resource = resources[i];

            MetadataReader metadataReader = null;
            try {
                //读取资源
                metadataReader = register.getMetadataReader(resource);
            } catch (IOException e) {
                continue;
            }
            //读取资源的注解配置
            AnnotationMetadata annotationMetadata = metadataReader.getAnnotationMetadata();
            //判断是否包含注解
            if (!annotationMetadata.hasAnnotation(annoClazz.getName())) continue;
            //类信息
            ClassMetadata classMetadata = metadataReader.getClassMetadata();
            //类全名
            String className = classMetadata.getClassName();
            try {
                //加载类
                ClassLoader classLoader = ClassLoader.getSystemClassLoader();
                Class<?> clazz = classLoader.loadClass(className);
                paths.add(clazz);
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            }
        }
        return paths;
    }


    public static void main(String[] args) {
        //测试
        Set<Class> clazz = getClazzFromAnnotation("com.pkg.fp", RSPI.class);

        System.out.println(clazz);


    }

}

转载于:https://my.oschina.net/lmxy1990/blog/3037703