Thread issue
I have a class named FoodListDay which represents all the meals for a day.
The Set foodListMeals is not supposed to contain any null elements. But since the attribute is set through setFoodListMeals I don't know what kind of Set is assigned to foodListMeals. If it is a HashSet for instance, null is a valid element type.
To fix this I introduced one line of code in setFoodListMeals that removes any null elements. But I fear that there might be some threading issues with this approach:
Thread A calls setFoodListMeals with a Set containing a null element. It executes the first line of code (assigns the Set to the attribute foodListMeals). It gets preempted by thread B. Thread B calls getFoodListMeals and gets back the set with the null element.
I'm not sure if making the method setFoodListMeals synchronized would take care of that because I don't completely understand thread/synchronization issues.
If thread B wants to call getFoodListMeals when thread A is executing setFoodListMeals, would making setFoodListMeals synchronized make thread B to wait until thread A is done (even though thread B doesn't try to access the synchronized method)?
Do I perhaps have to synchronize both methods to avoid any thread from accessing getFoodListMeals while another thread is already executing setFoodListMeals?
publicclass FoodListDay{
private Set foodListMeals;
public Set getFoodListMeals(){
return foodListMeals;
}
publicvoid setFoodListMeals(Set foodListMeals){
this.foodListMeals = foodListMeals;
this.foodListMeals.remove(null);// suggested fix.
}
}
