java 2 3
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Set of flashcards Details
| Flashcards | 496 |
|---|---|
| Language | Deutsch |
| Category | Computer Science |
| Level | Other |
| Created / Updated | 06.12.2020 / 24.01.2021 |
| Licencing | Not defined |
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What is the "principle of least privilege"?
Limiting access as much as possible
What is the problem here? How to fix?
public class GrasshopperCage {
public static void openLock(ComboLocks comboLocks, String combo) {
if(comboLocks.isComboValid("grasshopper", combo)) System.out.println("open");
}
}
a attacker could override the method isComboValid and pass it to openLock. (fix it by with final class) f.e:
public boolean isComboValid(String animal, String combo) {
var valid = super.isComboValid(animal, combo);
if(valid) { // email the password to s.b.}
return valid;
}
Is this a immutable object?:
public final class Animal {
private final ArrayList<String> favoriteFoods;
public Animal() {
this.favoriteFoods = new ArrayList<String>();
this.favoriteFoods.add("Apples");
}
public List<String> getFavoriteFoods() {
return favoriteFoods;
}
}
No, the returned list can be modified. Better implement methods for getting properties, f.e.:
public String getFavoriteFoodsElement(int index) {
return favoriteFoods.get(index);
}
What is a copy constructor?
F.e.:
public Animal(List<String> favoriteFoods) {
if(favoriteFoods == null) throw new Runtimeexception("..");
this.favoriteFoods = new ArrayList<String>(favoriteFoods);
}
