Question

In my utility method:

public static <T> T getField(Object obj, Class c, String fieldName) {
    try {
        Field field = c.getDeclaredField(fieldName);
        field.setAccessible(true);
        return (T) field.get(obj);
    } catch (Exception e) {
        e.printStackTrace();
        fail();
        return null;
    }
}

The line

return (T) field.get(obj);

gives the warning “Type safety: Unchecked cast from Object to T”;
but I cannot perform instanceof check against type parameter T,
so what am I suppose to do here?

Answer 1

The annotation @SuppressWarnings will stop the compiler reporting this warning. I don’t think there’s any way you can get away from the compiler warning when using reflection like this. Something like the following:

Field field = c.getDeclaredField(fieldName);
field.setAccessible(true);

@SuppressWarnings(value="unchecked")
T t = (T) field.get(obj);

return t;