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更新时间：2022-09-10 09:55:35
In ABAP we can define a static attribute for a class via keyword CLASS-DATA, whose validity is not associated with instances of a class but with the class itself. In order to prove this fact I use the following simple Pointer class for demonstration:
Can we access the static attribute of a class without object instance in debugger?
Since in theory the static attribute belongs to class instead of any dedicated object instance, so question comes: is there approach to monitor the static attribute value in ABAP debugger directly from class instead? Yes it is possible.
(1) type text “{C:ZCL_POINT} in debugger and press enter key
import java.lang.reflect.Field; public class Point { private int x; private int y; static private int count = 0; public Point(int x, int y){ this.x = x; this.y = y; count++; } private static void accessStaticPrivate(Point point){ Class classObject = point.getClass(); try { Field countField = classObject.getDeclaredField("count"); System.out.println("count: " + countField.get(point)); } catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException e1 ) { e1.printStackTrace(); } } public static void main(String[] arg){ Point a = new Point(1,2); accessStaticPrivate(a); Point b = new Point(1,3); accessStaticPrivate(b); Point c = new Point(1,4); accessStaticPrivate(c); Point d = new Point(1,5); accessStaticPrivate(d); } }
Unlike RTTI in ABAP, Java reflection can sometimes lead to security issues, see one example how Java Singleton would be bypassed in blog Singleton bypass – ABAP and Java.