[英]Implementing one to one relation ship spring hibernate
我有一张桌cards
,它与其他一些主表(部门和单位)具有一对一关系。
在UI上,我显示用于选择卡的除法和单位值的下拉列表,这是在CardController.java
创建表格的功能
@RequestMapping(value = "/addCardForm", method = RequestMethod.GET)
public String addCardForm(ModelMap map)
{
map.addAttribute("divisions", divisionService.getAllDivisions());
map.addAttribute("units", unitService.getAllUnits());
return "admin/addCard";
}
addCard.jsp
:
<form:form method="post" action="addCard">
<table cellspacing="10" id="card-table">
<tr>
<td><label for="division" class="control-label">Division : </label></td>
<td><select name="division" class="selectpicker">
<option>Select</option>
<c:forEach items="${divisions}" var="division">
<option value="${division.id}">${division.name}</option>
</c:forEach>
</select></td>
</tr>
<tr>
<td><label for="unit" class="control-label">Unit : </label></td>
<td><select name="unit" class="selectpicker">
<option>Select</option>
<c:forEach items="${units}" var="unit">
<option value="${unit.id}">${unit.name}</option>
</c:forEach>
</select></td>
</tr>
<tr>
<td><button type="submit" class="btn btn-primary">Submit</button></td>
<td></td>
</tr>
</table>
</form>
下拉列表中填充了数据,但在将其未设置的除法或单位提交给cardEntity对象时,将其设置为null,这是控制器中的addCard函数:
@RequestMapping(value = "/addCard", method = RequestMethod.POST)
public String addCard(@ModelAttribute(value="card") CardEntity card, BindingResult result)
{
cardService.addCard(card);
//card.getDivision(); -- this is null
return "redirect:/card";
}
除下拉菜单外,卡中还添加了其他字段。
CardEntity.java
@Entity
@Table(name="cards")
@Proxy(lazy=false)
public class CardEntity {
@Id
@Column(name="id")
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer id;
@OneToOne
@JoinColumn(name="division_id", referencedColumnName="id")
private DivisionEntity division;
@OneToOne
@JoinColumn(name="unit_of_qty_id", referencedColumnName="id")
private UnitEntity units;
public DivisionEntity getDivision() {
return division;
}
public void setDivision(DivisionEntity division) {
this.division = division;
}
public UnitEntity getUnits() {
return units;
}
public void setUnits(UnitEntity units) {
this.units = units;
}
}
编辑:
我必须手动设置divisionEntity和unitEntity:
@RequestMapping(value = "/addCard", method = RequestMethod.POST)
public String addCard(HttpServletRequest request, @ModelAttribute(value="card") CardEntity card, BindingResult result)
{
card.setDivision(divisionService.findOne(Integer.parseInt(request.getParameter("division"))));
card.setUnit(unitService.findOne(Integer.parseInt(request.getParameter("unit"))));
cardService.addCard(card);
return "redirect:/card";
}
所以我想这个问题是divisionEntity
和unitEntity
卡在提交表单之后对象未设置。
你也可以这样做:
<tr>
<td><label for="division.id" class="control-label">Division : </label></td>
<td><select name="division.id" class="selectpicker">
<option>Select</option>
<c:forEach items="${divisions}" var="division">
<option value="${division.id}">${division.name}</option>
</c:forEach>
</select></td>
</tr>
<tr>
<td><label for="unit.id" class="control-label">Unit : </label></td>
<td><select name="unit.id" class="selectpicker">
<option>Select</option>
<c:forEach items="${units}" var="unit">
<option value="${unit.id}">${unit.name}</option>
</c:forEach>
</select></td>
</tr>
其余与您的原件相同。 但:
Division
类中具有默认的构造函数; CardEntity
应该具有getUnit()
和setUnit()
,而不应该具有getUnit()
getUnits()
和setUnits()
。 希望对您有所帮助。
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