通过反射获取给定类的可访问方法列表 [英] Getting a list of accessible methods for a given class via reflection
问题描述
有没有办法获得给定类可以访问(不一定是公共)的方法列表?有问题的代码将在一个完全不同的类中。
Is there a way to get a list of methods that would be accessible (not necessarily public) by a given class? The code in question will be in a completely different class.
示例:
public class A {
public void methodA1();
protected void methodA2();
void methodA3();
private void methodA4();
}
public class B extends A {
public void methodB1();
protected void methodB2();
private void methodB3();
}
对于班级 B
我想得到:
- 所有自己的方法
-
methodA1
和methodA2
来自班级A
-
methodA3
当且仅当类B
与A $在同一个包中时c $ c>
- all of its own methods
methodA1
andmethodA2
from classA
methodA3
if and only if classB
is in the same package asA
methodA4
不应该包含在结果中,因为它无法访问上课 B
。为了再次澄清,需要查找并返回上述方法的代码将在完全不同的类/包中。
methodA4
should never be included in results because it's inaccessible to class B
. To clarify once again, code that needs to find and return the above methods will be in a completely different class / package.
现在,类。 getMethods()
只返回公共方法,因此不会执行我想要的操作; Class.getDeclaredMethods()
仅返回当前类的方法。虽然我当然可以使用后者并且在类层次结构中手动检查可见性规则,但我不愿意,如果有更好的解决方案。我在这里错过了一些明显的东西吗?
Now, Class.getMethods()
only returns public methods and thus won't do what I want; Class.getDeclaredMethods()
only returns methods for current class. While I can certainly use the latter and walk the class hierarchy up checking the visibility rules manually, I'd rather not if there's a better solution. Am I missing something glaringly obvious here?
推荐答案
使用 Class.getDeclaredMethods()
获取所有方法的列表(私有或来自类或接口。
Use Class.getDeclaredMethods()
to get a list of all methods (private or otherwise) from the class or interface.
Class c = ob.getClass();
for (Method method : c.getDeclaredMethods()) {
if (method.getAnnotation(PostConstruct.class) != null) {
System.out.println(method.getName());
}
}
注意:这不包括继承的方法。使用 Class .getMethods()
。它将返回所有 public 方法(继承或不继承)。
Note: this excludes inherited methods. Use Class.getMethods()
for that. It will return all public methods (inherited or not).
执行类可以访问的所有内容的完整列表(包括继承的方法) ,您将需要遍历它扩展的类树。所以:
To do a comprehensive list of everything a class can access (including inherited methods), you will need to traverse the tree of classes it extends. So:
Class c = ob.getClass();
for (Class c = ob.getClass(); c != null; c = c.getSuperclass()) {
for (Method method : c.getDeclaredMethods()) {
if (method.getAnnotation(PostConstruct.class) != null) {
System.out.println(c.getName() + "." + method.getName());
}
}
}
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