Question

I have a question regarding reflection in Java.

Following problem:
Depending on a configuration I want to call a method via reflection, but not only of a class CLASS_A, but also from a class CLASS_B that is referenced by CLASS_A.

But I want to use always only class CLASS_A to access the attribute.

Here an example what I mean:

public class Foo
{
   private String _name;
   private Bar _bar;
   public Foo(String name, Bar bar)
   {
      _name = name;
      _bar = bar;
   }

   public String getName()
   {
      return _name;
   }

   public Bar getBar()
   {
     return _name;
   }
}

public class Bar
{
   private String _name;

   public Bar(String name)
   {
     _name = name;
   }  

   public String getName()
   {
     return _name;
   }
}

I want to use always an instance of class Foo to invoke the method that is returned by getMethod … no matter whether the method of Foo should be called or the method of Bar.

public class Executor
{
   public static void main(String[] args)
   {
     Foo foo = new Foo("fooName", new Bar("barName"));
     String attribute = "barName";

     Method method = getMethod(Foo.class, attribute);

     try
     {
       System.out.println(String.valueOf(method.invoke(foo, new Object[]{})));
     }
    catch(Exception ex)
    {
       ex.printStackTrace();
    }
  }

 private static Method getMethod(Class< ? > clazz, String attribute)
 {
    try
    {
      if (attribute.equals("fooName"))
      {        
        return clazz.getDeclaredMethod("getName", new Class[] {});
      }
      else if (attribute.equals("barName"))
      {
        //Is that somehow possible?
        Method method = clazz.getDeclaredMethod("getBar.getName", new Class[] {});
        return method;
      }
    }
    catch (Exception ex)
    {
      ex.printStackTrace();
    }

    return null;
  }
}

Is something like that possible?
Thanks!

Answer 1

You can use Apache BeanUtils library.

Here is a good example of how you can use it.