问题描述
我想知道一个类的一些成员变量的注解,我用的BeanInfo的BeanInfo = Introspector.getBeanInfo(User.class)
内省一个类,并使用 BeanInfo.getPropertyDescriptors()
,找到特定的属性,并使用类键入= propertyDescriptor.getPropertyType()
来获取属性的类。
I want to know a class's some member variable's annotations , I use BeanInfo beanInfo = Introspector.getBeanInfo(User.class)
to introspect a class , and use BeanInfo.getPropertyDescriptors()
, to find specific property , and use Class type = propertyDescriptor.getPropertyType()
to get the property's Class .
但我不知道怎么去加入成员变量的注解?
But I don't know how to get the annotations added to the member variable ?
我试过 type.getAnnotations()
和 type.getDeclaredAnnotations()
,但都返回Class的注解,不是我想要的。例如:
I tried type.getAnnotations()
, and type.getDeclaredAnnotations()
, but both return the Class's annotations , not what I want . For example :
class User
{
@Id
private Long id;
@Column(name="ADDRESS_ID")
private Address address;
// getters , setters
}
@Entity
@Table(name = "Address")
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
class Address
{
...
}
我想获得该地址的注释:@Column,不类地址的注解(@Entity,@Table,@Cache)。如何实现呢?谢谢你。
I want to get the address's annotation : @Column , not class Address's annotations (@Entity , @Table , @Cache) . How to achieve it ? Thanks.
推荐答案
这是除了它的code mkoryak的变化不依赖于 Class.newInstance
(和它编译)。
This is a variation of the code mkoryak except it doesn't rely on Class.newInstance
(and it compiles).
for(Field field : cls.getDeclaredFields()){
Class type = field.getType();
String name = field.getName();
Annotation[] annotations = field.getDeclaredAnnotations();
}
参见:http://docs.oracle.com/javase/tutorial/reflect/class/classMembers.html
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