自己写个类加载器

public final class Classutil{	/*
		获取类加载器
	*/
	public static ClassLoader getClassLoader(){		return Thread.currentThread().getContextClassLoader();
	}        // 为提升性能，isInitialized默认为false
	public static Class<?> loadClass(String className, boolean isInitialized){		Class<?> cls;		try{
			cls = Class.forName(className,isInitialized,getClassLoader());
		}catch(ClassNotFoundException e){			throw new RuntimeException(e);
		}		return cls;
	}

}

public static Set<Class<?>> getClassSet(String packageName){
    Set<Class<?>> classSet = new HashSet<Class<?>>();    try{
        Enumeration<URL> urls = getClassLoader().getResources(packageName.replace(".","/"));        while(urls.hasMoreElements()){
            URL url = urls.nextElement();            if(url != null){
                String protocol = url.getProtocol();                if(protocol.equals("file")){
                    String packagePath = url.getPath().replaceAll("%20","");
                    addClass(classSet,packagePath,packageName);
                }else if (protocol.equals("jar")){
                    JarURLConnection jarURLConnection = (JarURLConnection)url.openConnection();                    if(jarURLConnection != null){
                        JarFile jarFile = jarURLConnection.getJarFile();                        if(jarFile != null){
                            Enumeration<JarEntity> jarEntities = jarFile.entries();                            while(jarEntries.hasMoreElements()){
                                JarEntity jarEntity = jarEntities.nextElement();
                                String jarEntityName = jarEntity.getName();                                if(jarEntityName.endWith(".class")){
                                    String className = jarEntryName.substring(0,jarEntryName.lastIndexOf(".")).replaceAll("/",".");
                                    doAddClass(classSet,ClassName);
                                }
                            }
                        }
                    }
                }
            }
        }
    }catch(Exception e){        throw new RuntimeException(e);
    }    return classSet;
}private static void addClass(Set<Class<?>> classSet, String packagePath, String packageName){    File[] files = new File(packagePaht).listFiles(new FileFilter(){
        @Override        public boolean accept(File file){            return (file.isFie() && file.getName().endWith(".class")) || file.isDirectory();
        }
    });    
    for(File file:files){
        String fileName = file.getName();        if(file.isFile()){
            Stirng className = fileName.substring(0,fileName.lastIndexOf("."));            if(!StringUtils.isBlank(packageName)){
                className = packageName + "."+className;
            }
            doAddClass(classSet, className);
        }else{
            String subPackagePath = fileName;            if(!StringUtils.isBlank(packagePath)){
                subPackagePath = packagePath + "/"+subPackagePath;
            }
            String subPackageName = fileName;            if(!StringUtils.isBlank(packageName)){
                subPackageName = packageName + "."+subPackageName;
            }
            addClass(classSet,subPackagePath,subPackageName);
        }
    }
}private static void doAddClass(Set<Class<?>> classSet, String className){    Class<?> cls = loadClass(className, false);
    classSet.add(cls);
}

private static Set<Class<?>> CLASS_SET;public static void init(String basePackage){
    CLASS_SET = ClassBuilder.getClassSet(basePackage);
}/* 获取包下所有的类 */public static Set<Class<?>> getClassSet(){    return CLASS_SET;
}/* 获取包下所有指定注解的类 */pubic static Set<Class<?>> getAnnoClassSet<Class<?> extends Annotation annoClass>{
    Set<Class<?>> classSet = new HashSet<>();    for(Class<?> cls : CLASS_SET){        if(cls.isAnnotationPresent(annoClass)){
            classSet.add(cls);
        }
    }    return classSet;
}