Question

我有一个创建新办公室的MVC应用程序，而不是在使用编辑表单时更新它们。请帮助我理解为什么会这样。

填充搜索结果的搜索方法：

@RequestMapping(value = "/searchResults", method = RequestMethod.POST)
public ModelAndView search(@RequestParam String searchCriteria, HttpServletRequest request) {
    List<Office> offices = officeServiceImpl.search(searchCriteria);
    return new ModelAndView("searchResults", "offices", offices);
}

以下是搜索结果页面上编辑表单的链接：

<a href="${pageContext.request.contextPath}/app/office/${office.getId()}/edit" class="btn btn-success">Edit Office</a>

以下是Controller的编辑GET方法，该方法使用现有Office填充表单：

@RequestMapping(value = "/{officeId}/edit", method = RequestMethod.GET)
@Transactional(noRollbackFor=NoResultException.class)
public ModelAndView initUpdateOfficeForm(
    @PathVariable("officeId") Long officeId, Model model) {
    Office office = officeServiceImpl.find(officeId);
    //prepareEditFormModelAndView(office) just converts some objects to strings for typeahead form population
    return prepareEditFormModelAndView(office);
}

这是编辑POST方法：

@RequestMapping(value = "/{officeId}/edit", method = RequestMethod.POST)
public ModelAndView processUpdateOfficeForm(@ModelAttribute("office") @Valid Office office,
        BindingResult result, SessionStatus status) {
    if (! "united states of america".equals(office.getFolderStrings().toLowerCase())) {
        //This portion of code converts the typeahead strings to objects
        result = tryCountries(office, result);
        result = tryDepartments(office, result);
        result = tryEmployees(office, result);
        }
        if (result.hasErrors()) {
        return prepareEditFormModelAndView(office);
    } else {
        officeServiceImpl.save(office);
        status.setComplete();
        return new ModelAndView("editResult", "office", office);
    }
}

officeServiceImpl调用officeRepositoryImpl方法保存，如下所示：

@Override
public Office save(Office office) {
    em.merge(office);
    em.flush();
    return office;
}

由于

编辑：添加prepareEditFormModelAndView（office），此方法尝试从关联对象构建字符串：

@Transactional(noRollbackFor={NoResultException.class, IndexOutOfBoundsException.class})
private ModelAndView prepareEditFormModelAndView(Office office) {
    String departmentStrings = "";
    String employeeStrings = "";

    List<OOM> officeOOMs = new ArrayList<OOM>();
    StringBuilder sb = new StringBuilder();
    try {
        officeOOMs = oomServiceImpl.getOOMsForCurrentOffice(office.getId());
    } catch (NoResultException e) {
        officeOOMs = null;
    }
    for (OOM o : officeOOMs) {
        try {
            Employee tempEmployee = employeeServiceImpl.find(o
                    .getEmployeeId());
            sb.append(tempEmployee.getDisplayName() + ", ");
        } catch (NoResultException e) {
            sb.append("Not found in system");
        }
    }
    employeeStrings = sb.toString();

    if ((! "".equals(office.getDepartmentStringsOnForm())) && office.getDepartmentStringsOnForm() != null) {
        departmentStrings = office.getDepartmentStringsOnForm();
    }
    String folderStrings = "";
    try {
        folderStrings = kmlFolderServiceImpl.getInternationalOfficeString(office.getId());
        LOGGER.info("Folder Strings: " + folderStrings);
    } catch (NoResultException e) {
        folderStrings = "";
        LOGGER.info("Folder Strings: " + "no result");
    }
    boolean isInternational = office.isInternational();
    ModelAndView result = new ModelAndView("editOfficeForm", "office", office);
    result.addObject("departmentStrings", departmentStrings);
    result.addObject("isInternational", isInternational);
    result.addObject("folderStrings", folderStrings);
    result.addObject("employeeStrings", employeeStrings);
    return result;
}

Answer 1

我在此处添加了之前的评论，以便更好地澄清。根据OP，以下问题解决了这个问题：

当ID不在表单中时，当模型被回发时，没有为实体设置ID，使得持久性提供者认为它是新实体。因此，最明显的解决方案是在保存操作中发布实体的ID（可能使用隐藏字段）。

另一种解决方案是尝试根据某些业务密钥在数据库中加载实体查看实体是否是新的。

Spring MVC，尝试编辑但创建新对象

1 个答案: