我正在尝试使用javassist
动态地向类添加注释我的代码如下
Class annotatedClass = addFrequencyAnnotation(MyClass.class.getSimpleName(),
MyAnnotation.class.getSimpleName(), 10);
annotatedClass.isAnnotationPresent(MyAnnotation.class); // Returns false
但是返回的类没有添加注释。
TextView[] containers=new TextView[2];
我不确定我的代码中缺少什么。有人可以帮助确定问题吗?
答案 0 :(得分:1)
您应该使用MyAnnotation.class.getName
而不是MyAnnotation.class.getSimpleName
。因为MyAnnotation
但没有yourpackage.MyAnnotation
。
public static void main(String[] args) throws Exception {
Class<?> annotatedClass = addAnnotation(MyClass.class.getName(), MyAnnotation.class.getName(), 10);
System.out.println(annotatedClass.getAnnotation(MyAnnotation.class));
}
private static Class<?> addAnnotation(String className, String annotationName, int frequency) throws Exception {
ClassPool pool = ClassPool.getDefault();
CtClass ctClass = pool.makeClass(className + "1");//because MyClass has been defined
ClassFile classFile = ctClass.getClassFile();
ConstPool constpool = classFile.getConstPool();
AnnotationsAttribute annotationsAttribute = new AnnotationsAttribute(constpool, AnnotationsAttribute.visibleTag);
Annotation annotation = new Annotation(annotationName, constpool);
annotation.addMemberValue("frequency", new IntegerMemberValue(classFile.getConstPool(), frequency));
annotationsAttribute.setAnnotation(annotation);
ctClass.getClassFile().addAttribute(annotationsAttribute);
return ctClass.toClass();
}