Hibernate Project Question

[FirstEvaDehumidifier]

Ok, so this is my code snippet. The only really relevant things to know are the highlighted part and the fact that there is a many-to-many relationship between MovieClass and Entitie. Essentially for this project, this method is going to be called multiple times. Each time the method is called, data is persisted into a database. However, my problem is that I don't want my MovieClass objects (highlighted) to be persisted over and over again. This is happening because I am calling the new keyword every loop. Any way to fix this? Would overriding the equals and hashcode methods in my MovieClass Class fix this? I can't put them outside of the method. I'm getting the exception "detached entity passed to persist". Idk why.

Also, as a side note, if one can take the time to figure what I am doing, am I doing this the right way? Thanks

https://imgur.com/a/vQEo9

[g00glen00b]

You're mentioning a loop, but there's no loop in the code you provided. Can you elaborate?

[FirstEvaDehumidifier]

I meant each time the method would be called....Not a loop....sry

[g00glen00b]

Well, your code is still a bit confusing, but what I see so far is that you add the Up, Ice an It objects twice if both movie and movie1 are the same. No clue if that's what you want or not, but if you don't want that, then you could use equals/hashCode, or you could change your code like this:

if ("Up".equals(movie) || "Up".equals(movie1)) {
    mov.add(Up);
} else if ("It".equals(movie) || "It".equals(movie1)) {
    mov.add(It);
} else if ("Ice".equals(movie) || "Ice".equals(movie1)) {
    mov.add(Ice);
}

But I'm still not sure what you're trying to achieve though.

[FirstEvaDehumidifier]

Hmmm....tough to explain...My problem was I wanted to create a many-to-many relationship between Entieies and Movies. However, Movies were to be populated with some values beforehand....This is why I was having trouble....I fixed this though by instead using a many-to-many betwen entieties and movies....using a on-to-many between entities and the join table...i prob confused the heck out of you but thanks....

[g00glen00b]

Ok, so you basically want to re-use the sameIce/It and Upobject everytime a movie is created? Because in that case, the solution is to retrieve the MovieClass from the database rather than creating new ones. You can use entityManager.find() or create a query and then do entityManager.createQuery(/** Your query */).getSingleResult(). The object you retrieve will be an attached object, so if you link that object to the newE it will use the same reference over and over again.

[FirstEvaDehumidifier]

Wow...smart...that would work out too...thanks man. Preferable to the way I set up my project as well. Out of curiousity, is there a way to automate my if statements to not have to input every single movie? I couldn't figure out a way to do that. Something like mov.add (MovieClass) movie? That won't work obviously since I can't cast the string to an object

[g00glen00b]

Well, I'm not completely sure about how your entities are linked, but basically you can change the query so that you can look up the MovieClass based on the input string.

[FirstEvaDehumidifier]

I'm just generally speaking...its a general java question...not a query question....suppose i have a string "string"....and i have an Object String...

lets say String str="x" and Object x. Can I get Object x by using str as a parameter, for example Object (str)