Need some help on fixing this
#Ive been getting errors on saving and loading part in my code, need help
gilded oriole
vocal gustBOT
<@&987246399047479336> please have a look, thanks.
Here is an AI assisted attempt to answer your question 🤖. Maybe it helps! In any case, a human is on the way 👍. To continue talking to the AI, you can use </chatgpt:1108714622413963314>.
Sure, I'd be happy to help you with your Java code. Could you please provide more details about the errors you are encountering and share the relevant code snippets?
hallow path
do what the error says?
your shoppingmananger interface conains a method SaveList (which should be saveList) which must either be implemented, or your class must be abstract
patent mortar
apparently ur WestminsterShoppingManager hasnt implemented SaveList() yet
could u share both classes please
full code ideally. not just pics
gilded oriole
ill send
gilded oriole
apparently ur `WestminsterShoppingManager` hasnt implemented `SaveList()` yet
the full code
i keep trying to fix it
but i just go in circles
patent mortar
can u just share the two classes WestministerShoppingManager and ShoppingManager
then its easier to access
🙂
patent mortar
yeah, but dont delete the gist please 😄
patent mortar
without gist, its not visible for mobile users
gilded oriole
vocal gustBOT
I uploaded your attachments as Gist.
gilded oriole
i thought dismiss meant just removing that msg
patent mortar
👍
mh, odd. looks right
void SaveList(String Fname, List<Product> products);
// ...
public void SaveList(String Fname, List<Product> products) {
patent mortar
what happens if u click on Implement Methods?
gilded oriole
it just creates savelist and loadlist again
hallow path
it's not ok
gilded oriole
gilded oriole
yeah
hallow path
and you only implemented the one with arguments
patent mortar
its not on the gist u uploaded though, lol
gilded oriole
and you only implemented the one with arguments
when i do put arguments theres an erroe
patent mortar
ur misunderstanding
ur interface, the way u wrote it, demands that there are 2 SaveList methods
one with args
and one without
so every class that implements the manager MUST offer both of them
hallow path
you have an overloaded method
gilded oriole
i awnt the one with arguments
patent mortar
dont do random changes to ur code
get rid of what u dont need
and then fix the issues that pop up
gilded oriole
patent mortar
yeah. the method wants a name and a lis tof products to save
gilded oriole
get rid of what u dont need
got rid of the unncerssary stuff now
patent mortar
u cant just call it without anything
SaveList("foo", someProducts)
u have to give it the args
gilded oriole
patent mortar
arguments mean that u expect them from the caller
gilded oriole
i havent inputed anything into my main yet
patent mortar
u have to pass them when u call it
how should SaveList know what to save when u dont give it anything to save
it cant guess it
hallow path
It expects something like:
String Fname = "foo";
List<Product> products = new ArrayList<>();
SaveList(Fname, products);
(but with reasonable content)
gilded oriole
It expects something like:
```java
String Fname = "foo";
List<Product> product...
this goes into main?
hallow path
kind of, it's just a sample of what will compile
Fname, and products should be reasonable content
it's just to showcase that when you declare a method that expects something, you do need to pass it in
gilded oriole
it's just to showcase that when you declare a method that expects something, you...
i didnt get it
hallow path
you declared your method as saying: I want an input of a String and a list of products, but you gave it nothing.
gilded oriole
so what i want to do with save is
take the stuff in product and write it into a file
what ur saying is i didnt give it the product?
gilded oriole
you called SaveList without any arguments
inside the case?
hallow path
saveList() <= you passed in nothing
gilded oriole
hallow path
and now it doesn't complain
gilded oriole
damn
okay i understood what just happened lmao
same with load im assuming?
okay it did save
but it saved some weird shit
hallow path
load expects your fname
vocal gustBOT
gilded oriole
load expects your fname
i get a weird text in my saved file
it aint savin
@hallow path can u help me out with the saving and loading?
hallow path
working on a hobby project, but your class is most likely not Serializable (and a good toString never hurts)
gilded oriole
working on a hobby project, but your class is most likely not Serializable (and ...
what do i do then?
hallow path
make your Product Serializable
gilded oriole
make your Product Serializable
ok ill give it a try
gilded oriole
make your Product Serializable
instead of the way i did
is there a different way of doing it instead of making product "serializable"?
hallow path
Only objects that support the java.io.Serializable interface can be written to streams. The class of each serializable object is encoded including the class name and signature of the class, the values of the object's fields and arrays, and the closure of any other objects referenced from the initial objects.
The method writeObject is used to write an object to the stream. Any object, including Strings and arrays, is written with writeObject. Multiple objects or primitives can be written to the stream. The objects must be read back from the corresponding ObjectInputstream with the same types and in the same order as they were written.
Primitive data types can also be written to the stream using the appropriate methods from DataOutput. Strings can also be written using the writeUTF method.
The default serialization mechanism for an object writes the class of the object, the class signature, and the values of all non-transient and non-static fields. References to other objects (except in transient or static fields) cause those objects to be written also. Multiple references to a single object are encoded using a reference sharing mechanism so that graphs of objects can be restored to the same shape as when the original was written.
For example to write an object that can be read by the example in ObjectInputStream:
FileOutputStream fos = new FileOutputStream("t.tmp");
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeInt(12345);
oos.writeObject("Today");
oos.writeObject(new Date());
oos.close();
Classes that require special handling during the serialization and deserialization process must implement special methods with these exact signatures:
private void readObject(java.io.ObjectInputStream stream)
throws IOException, ClassNotFoundException;
private void writeObject(java.io.ObjectOutputStream stream)
throws IOException
private void readObjectNoData()
throws ObjectStreamException;
i cant do something like this?
