如何在Spring的JSR 303中仅显示多行验证错误消息？

Question

有一个具有多行的网格。 每行都有两个相同的文本字段。 我正在使用JSR 303来验证这些字段，并且验证正在进行中。 但是，问题在于显示了多个错误消息（每行一个），这是不希望的。 有没有一种方法可以针对所有行在每个字段中仅显示一条错误消息？

public ModelAndView insert(@Valid @ModelAttribute("proposalwiseselectionform")ProposalWiseSelectionForm proposalwiseselectionformobj,
                               BindingResult result,
                               HttpServletRequest request, HttpServletResponse response) {
        if (result.hasErrors()) {
            if (formBeanObj == null) {
                formBeanObj = proposalwiseselectionformobj;
            }
            mav = new ModelAndView("proposalwiseselection");

            mav.addObject("proposalwiseselectionform", formBeanObj);
        }
    }




public class ProposalWiseSelectionForm {
private String txtLineOfBusiness;
private String txtProduct;
private String btn;
private String clickedGo="N";   
private List arrLineOfBusiness=new ArrayList();
private List arrProduct=new ArrayList();
@Valid
private ArrayList documentList=initiateDocumentList();
private String txtPageMode="I";
private String enableDiscardBtn="N";
private String enableInsertBtn="N";

public ArrayList initiateDocumentList(){
    ArrayList arr=new ArrayList();
    for(int i=0; i<1;i++){
      arr.add(new ProposalWiseSelectionChildForm(i));
    }
    return arr;
  }
}



public class ProposalWiseSelectionChildForm {

private String numProposalWiseSelection;        
private String txtTransactionType;
private String txtTransactionTypeCode;  

@NotEmpty(message="Transaction Type cannot be empty")
private String txtTransactionDesc;

@NotEmpty(message="Document Type cannot be empty")
private String txtPolicyDocument;
private String ynChkBox="0";

}

JSP片段如下，

form:form action="/proposalwiseselection" commandName="proposalwiseselectionform" method="POST" id="proposalwiseselection"/  
form:errors path="*" cssClass="errorblock" element="div"/
form:input path="documentList[${docStatus.index}].txtTransactionDesc"  cssClass="noneditableinputbox" size="40" onkeydown="transactionTypeLOV(event.keyCode,this)" readonly="true" title="Press F2 to get transaction type list" /
form:hidden path="documentList[${docStatus.index}].txtTransactionTypeCode"/
form:input path="documentList[${docStatus.index}].txtPolicyDocument"  cssClass="noneditableinputbox" size="40"  readonly="true"/
form:hidden path="documentList[${docStatus.index}].numPolicyDocumentCode"/

Answer 1

尽管以下解决方案非常粗糙，但是它可以执行所需的功能。 您可以轻松地使工作更具可读性并遵循Spring原则，但是我只是简单地说明了如何完成您所要求的工作。

首先，您需要首先从Spring获取Validator 。

@Autowired
Validaror validator;

接下来，您需要删除@Valid批注并自行执行验证。

这意味着您的方法将如下所示：

public ModelAndView insert(@ModelAttribute("proposalwiseselectionform")ProposalWiseSelectionForm proposalwiseselectionformobj,
                               BindingResult result,
                               HttpServletRequest request, HttpServletResponse response)

{
        validate(bindingResult);
        if (result.hasErrors()) {
            if (formBeanObj == null) {
                formBeanObj = proposalwiseselectionformobj;
            }
            mav = new ModelAndView("proposalwiseselection");

            mav.addObject("proposalwiseselectionform", formBeanObj);
        }
}

最后，validate方法将如下所示：

private void validate(BindingResult bindingResult) {

    final BindingResult intermediateBindingResult = new BeanPropertyBindingResult(bindingResult.getTarget(), bindingResult.getObjectName()) ;
    validator.validate(bindingResult.getTarget(), intermediateBindingResult);

    final List<FieldError> originalFieldErrors = intermediateBindingResult.getFieldErrors();
    final Set<String> alreadyAddedFieldNames = new HashSet<>();
    final List<FieldError> distinctFieldErrors = new ArrayList<>();
    for (FieldError fieldError : originalFieldErrors) {
        if(alreadyAddedFieldNames.contains(fieldError.getField())) {
            continue;
        }

        distinctFieldErrors.add(fieldError);
        alreadyAddedFieldNames.add(fieldError.getField());
    }

    for (FieldError distinctFieldError : distinctFieldErrors) {
        bindingResult.addError(distinctFieldError);
    }
}

上面的代码所做的是将常规验证存储到中间绑定结果中，并遍历所有FieldError并在每个字段中仅添加第一个。