Spring 4 MVC Form: Create Object with list of sub objects - spring

Question

I looking for help in understanding how to create a new object through a form which has the user select multiple sub-objects (which will come pre-populated) and available to select with a checkbox.
OrderController.java
#RequestMapping(value = { "/order" }, method = RequestMethod.GET)
public String order(ModelMap model) {
List<Exam> exams = examService.findAllExams();
List<Document> documents = documentService.findAllDocuments();
model.addAttribute("exams", exams);
model.addAttribute("documents", documents);
return "order"; // jsp page reference
}
Order.java
#Entity
#Table(name="\"order\"")
public class Order implements Serializable
{
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name = "order_id", unique = true, nullable = false)
private Integer id;
#GeneratedValue(generator = "uuid")
#GenericGenerator(name = "uuid", strategy = "uuid2")
#Column(name = "uuid", unique = true, nullable = false)
private String uuid;
#Temporal(TemporalType.DATE)
#Column(name = "order_date", unique = true, nullable = false)
private Date orderDate;
#Column(name="order_status", nullable=false)
private String orderStatus;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "user_id", nullable = false)
private User user;
#OneToMany(fetch = FetchType.LAZY, mappedBy = "order")
private Set<OrderExam> orderExams = new HashSet<OrderExam>(0);
#OneToMany(fetch = FetchType.LAZY, mappedBy = "order")
private Set<OrderDocument> orderDocuments = new HashSet<OrderDocument(0);
//getters & setters
}
OrderExam.java
#Entity
#Table(name="order_exam")
public class OrderExam implements Serializable
{
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name = "order_exam_id", unique = true, nullable = false)
private Integer id;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "order_id", nullable = false)
private Order order;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "exam_id", nullable = false)
private Exam exam;
#Column(name="exam_amount", nullable=true)
private Integer examAmount;
#Column(name="answer_sheet_amount", nullable=true)
private String answerSheetName;
#Column(name="students_per_csv", nullable=true)
private String studentsPerCSV;
#Column(name="pas", nullable=true)
private Boolean pearsonAnswerSheet;
//getters & setters
}
Exam.java
#Entity
#Table(name="exam")
public class Exam implements Serializable
{
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name = "exam_id", unique = true, nullable = false)
private Integer id;
#NotEmpty
#Column(name="name", unique=true, nullable=false)
private String name;
#NotEmpty
#Column(name="code", unique=true, nullable=false)
private String code;
#OneToMany(fetch = FetchType.LAZY, mappedBy = "exam")
private Set<OrderExam> exams = new HashSet<OrderExam>(0);
//getters & setters
}
As you can see I am passing in a list of exams and documents which will populate a form with available options (can be seen in the image below (exams anyway)). The user needs to be able to select multiple rows, so that a single order has multiple exams and documents associated to it.
My order.jsp is a little much to post the entire thing here but here is the part I have which is displayed in the image above.
Order.jsp
<form:form method="POST" modelAttribute="order" class="form-horizontal form-label-left">
<c:forEach items="${exams}" var="exam">
<tr>
<th scope="row"><input type="checkbox" class="flat"></th>
<td><input id="middle-name" type="text" name="middle-name" readonly="readonly" value="${exam.name} - ${exam.code}" class="form-control col-md-7 col-xs-12"></td>
<td><input id="middle-name" type="text" name="middle-name" value="0" class="form-control col-md-3 col-xs-12"></td>
<td><input id="middle-name" type="text" name="middle-name" value="0" class="form-control col-md-3 col-xs-12"></td>
<td><input id="middle-name" type="text" name="middle-name" value="0" class="form-control col-md-3 col-xs-12"></td>
<c:choose>
<c:when test="${exam.name == 'Algebra 2 (Common Core)'}">
<th scope="row"><input type="checkbox" class="flat"></th>
</c:when>
<c:otherwise>
<th scope="row"></th>
</c:otherwise>
</c:choose>
</tr>
</c:forEach>
<!-- Other Stuff Goes Here -->
</form:form>
So in short, would someone be willing to show me how to set up the form in the way I described above? Thanks in advance.

Answer 1

Your question is a bit broad however you could try this as below. I have only covered exams. Principal for documents will be the same.
You will need a couple of new classes to capture the submitted form inputs:
Order Form to Capture Selections
public class OrderForm{
private List<ExamWrapper> allAvailableExams = new ArrayList<>();
private XOptionPrintWrapper selectedWrapper;
public OrderForm(){
}
//getters and setters
}
Exam Wrapper : Decorates an Exam with a 'selected' property
public class ExamWrapper{
private boolean selected;
private Exam exam;
public ExamWrapper(Exam exam){
this.exam = exams;
}
//getters and setters
}
Change Contoller to
public class OrderController{
//Exams model populated by the method below
//moved as we also need it populated on POST
#RequestMapping(value = { "/order" }, method = RequestMethod.GET)
public String order(ModelMap modelMap) {
//only needed on GET so put in model here
List<XOptionPrintWrapper> availableWrappers = //someList;
modelMap.put("availableWrappers", availableWrappers);
return "order";
}
//handles for submit
//model atribute is automatically populated by the framework
#RequestMapping(value = { "/order" }, method = RequestMethod.POST)
public String order(#ModelAttribute("orderForm") OrderForm orderForm) {
//process selected exams
return "nextView";
}
//on get populates the initial model for display
//on post create an instance which the form params will be bound to
#ModelAttribute("orderForm")
public OrderForm getOrderForm(){
OrderForm orderForm = new OrderForm();
List<Exam> exams = examService.findAllExams();
for(Exam exam : exams){
orderForm.getAllAvailableExams.add(new ExamWrapper(exam));
}
return orderForm;
}
}
In JSP use Sping support for binding to indexed properties:
<form:form method="POST" modelAttribute="orderForm" class="form-horizontal form-label-left">
<c:forEach items="${orderForm.allAvailableExams}" var="exam" varStatus="status">
<tr>
<th scope="row"><input name="allAvailableExams[${status.index}].selected"
type="checkbox" class="flat"></th>
</tr>
</c:forEach>
<form:select path="selectedWrapper">
<form:options items="${availableWrappers}"
itemValue="somePropertyOfXOptionPrintWrapper "
itemLabel="somePropertyOfXOptionPrintWrapper " />
</form:select>
</form>
I obviously haven't been able to try all of this but think it should all be okay.