I would like to save an object C from a form. This form contains of two select drop downs each represents class A and class B.
Class C has a connection to class A and class A has a list connection to class B.
When I save object C from form I choose one item from select drop down class A and one item from class B.
The new ID of C and the choosen ID of A is saved to a db table db_C and choosen ID of B is supposed to be saved together with newly created ID of C and a new ID of D to a db table db_D which contains connections to B and C.
Table db_A
__A__
1
2
3
Table db_B
__B__|__C__
4 | 2
5 | 1
Table db_C
__C__|__A__
1 | 2
2 | 3
Table db_D
__D__|__B__|__C__
1 2 1
I have a controller of C:
@RequestMapping(value = "/new", method = RequestMethod.GET)
public String add(Model model) {
model.addAttribute("listOfAs", listOfAs());
model.addAttribute("C", new C());
model.addAttribute("listOfBs", listOfBs());
return "C/edit";
}
private List<B> listOfBs() {
List<B> listOfBs = new ArrayList<>();
try {
listOfBs.addAll(BService.listBs());
} catch(DataAccessException ex) {
logger.error(ex.getMessage(), ex);
}
return listOfBs;
}
private List<A> listOfAs() {
List<A> listOfAs = new ArrayList<>();
try {
listOfAs.addAll(AService.listAs());
} catch (DataAccessException ex) {
logger.error(ex.getMessage(), ex);
}
return listOfAs;
}
@RequestMapping(value = "/save", method = RequestMethod.POST)
public String update(Model model, @ModelAttribute("C") C C, BindingResult CResult) {
C.setA(AService.getA(C.getA().getID()));
System.out.println(C.getA().getBs().isEmpty()); //Prints "True"
if (C.getID() == 0) {
CService.save(C);
} else {
CService.update(C.getID(), C);
}
return "redirect:/mvc/C/viewList";
}
And my form of C
<s:url value="/mvc/C/save" var="actionUrl" />
<sf:form method="POST" modelAttribute="C" action="${actionUrl}">
<fieldset>
<table>
<tr>
<th><label for="A">A:</label></th>
<td><sf:select path="A.ID">
<sf:option value="0"> </sf:option>
<sf:options items="${listOfAs}" itemLabel="name" itemValue="ID" />
</sf:select></td>
</tr>
<tr>
<th><label for="B">B:</label></th>
<td>
<sf:select path="A.listRefToB">
<sf:option value="0"> </sf:option>
<sf:options items="${listOfBs}" itemLabel="name" itemValue="ID" />
</sf:select>
</td>
</tr>
<tr>
<td colspan="2">
<input id="saveButton" class="right" type="submit" title="Save" value=" [ Save ] " />
</td>
</tr>
</table>
</fieldset>
</sf:form>
The problem is that when I save I get an empty list of Bs. I think it's because C doesn't have a direct reference to B. But I'm not sure. I really need help with this! How do get selected value of B into the save-function??
I've tried these two links with no result
List<Foo> as form backing object using spring 3 mvc, correct syntax?
How to send list of Objects to View and back to Post method in controller
I didn't get the names and id's into the optiontag.
The goal in this is to choose A and B in the form for C and on save I'd like to save all values I enter in form to db_C and db_D respectivly.
I hope someone can help me :)
I edited the question because the first one was a bit confusing.
