Why is it allowed to access Java private fields via reflection?

java reflection private-members
Savvas Dalkitsis picture Savvas Dalkitsis · Aug 6, 2009 · Viewed 8.8k times · Source

Consider this example :

import java.lang.reflect.Field;

public class Test {

    public static void main(String[] args) {
        C c = new C();
        try {
            Field f = C.class.getDeclaredField("a");
            f.setAccessible(true);
            Integer i = (Integer)f.get(c);
            System.out.println(i);
        } catch (Exception e) {}
    }
}

class C {
    private Integer a =6;
}

It seems illogical that you are allowed to access private fields of classes with reflection. Why is such a functionality available? Isn't it "dangerous" to allow such access?

Answer

jcoder picture jcoder · Aug 6, 2009

Private is intended to prevent accidental misuse, not as a security mechanism. If you choose to bypass it then you can do so at your own risk and the assumption you know what you are doing.

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