Value is not valid using entryset - jpa

Question

This issue arrived when I tried to use a LinkedHashMap to save entries from a database. I don't know to what extent the xhtml code is working, but superficially looks well.
The issue is in this part of the xhtml:
<tbody>
<tr>
<td>Movie:</td>
<!--td>
<h:selectOneMenu id="foundmovieid" value="#{webRental.idmovie}">
<f:selectItems id="movieid" value="#{webMovie.get_all_movies()}"></f:selectItems>
</h:selectOneMenu>
</td-->
<td>
<h:selectOneMenu value="#{webRental.idmovie}">
<f:selectItems value="#{webMovie.availableMovies.entrySet()}" var="entry"
itemValue="#{entry.key}" itemLabel="#{entry.value}" />
</h:selectOneMenu>
</td>
</tr>
</tbody>
</table>
<h:commandButton value="Submit" action="#{webRental.save()}"></h:commandButton>
Here is the WebRental.java:
public class WebRental {
#EJB
private RentalsFacade rf;
private String iduser;
private String idmovie;
//getters and setters
public List<Rentals> get_all_rents() {
return rf.findAll();
}
public void save() {
try {
rf.Save(iduser, idmovie);
} catch (Exception e) {
}
}
}
and the WebMovie.java, whose MoviesFacade has an EntityManager and a way to persist new pbject Movies (id, title, director's name and length):
#Named
#RequestScoped
public class WebMovie {
#EJB
private MoviesFacade mf;
private String id;
private String title;
private String director;
private int length;
private Map<String, String> availableMovies;
//geters and setters
public List<Movies> get_all_movies() {
availableMovies = new LinkedHashMap<>();
List<Movies> found = mf.findAll();
found.forEach((m) -> {
String first = m.getId();
String second = m.getTitle() + ", " + m.getDirector() + ", " + m.getLength() + " minutes.";
availableMovies.put(first,second);
});
return mf.findAll();
}
public void save() {
try {
mf.Save(id, title, director, length);
} catch (Exception e) {
}
}
}
In the xhtml, theres a muted section, which is just what I have to do (get id's and submit them) but in a way that you only see the id's. The unmuted section is the part im having trouble with, since it says that the value is invalid.
To solve this do I have to use "converters"? If so, how do I implement it? If not, what is my error?
Also, in the muted section there is a call to "get_all_movies()", but since it's muted, it shouldnt be called. How do I call that function outside of that muted section so I can delete the whole section after I get the SelectOneMenu with the map working?

Answer 1

Turns out using Maps is very strange...
How I solved this was by removing most of the SelectItems so that it just is:
<f:selectItems value="#{webMovie.availableMovies}" />
And then changing the way I insert everything to the Map like so:
#PostConstruct
public void init() {
availableMovies = new HashMap<>();
mf.findAll().forEach((m) -> {
availableMovies.put((String) m.getTitle() + ", " + m.getDirector() + ", " + m.getLength() + " minutes.",(String) m.getId());
});
//Turns out that, for the selectItems to read properly the map, you have to insert the text you want to be displayed as the key, and then the value as value. I was doing it backwards.
}
That way I dont have to depend on the !--'d section that calls get_all_movies() and I could delete it!