检测java中带有特定注释的所有类。

import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

public class ClassAnnotationDetector {
    public static List<Class<?>> getClassesWithAnnotation(String packageName, Class<? extends Annotation> annotationClass) {
        List<Class<?>> classes = new ArrayList<>();
        try {
            ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
            String path = packageName.replace('.', '/');
            java.net.URL resource = classLoader.getResource(path);
            if (resource != null) {
                java.io.File directory = new java.io.File(resource.getFile());
                if (directory.exists()) {
                    String[] files = directory.list();
                    for (String file : files) {
                        if (file.endsWith(".class")) {
                            String className = packageName + '.' + file.substring(0, file.length() - 6);
                            Class<?> clazz = Class.forName(className);
                            if (clazz.isAnnotationPresent(annotationClass)) {
                                classes.add(clazz);
                            }
                        }
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return classes;
    }

    public static void main(String[] args) {
        List<Class<?>> classes = getClassesWithAnnotation("com.example", MyAnnotation.class);
        for (Class<?> clazz : classes) {
            System.out.println(clazz.getName());
        }
    }
}