如何從日歷驗證日期

Question

我已經嘗試了以下代碼（我已經按照一個例子）來測試從日歷中選擇的日期。 如果我的數據庫中不存在該日期，則應向最終用戶顯示驗證錯誤消息。 但是，錯誤不會在<h:message> ，而是記錄到服務器日志中。

視圖：

<p:calendar id="date1" value="#{bean.date1}" showOn="button"> 
    <f:validator validatorId="calendarValidator" />
    <f:ajax execute="date1" render="calendarmessage" />
</p:calendar>
<h:message id="calendarmessage" for="date1" />

驗證器：

@FacesValidator("calendarValidator")
public class CalendarValidator implements Validator{

    @Override  
    public void validate(FacesContext context, UIComponent component, Object value) {
        java.util.Date date2 = (java.util.Date) value;

        try {
            if (validateDate(date2)) {
                throw new ValidatorException(new FacesMessage("A valid date"));
            } else {
                throw new ValidatorException(new FacesMessage("date dont figure in the database"));
            } 
        } catch(Exception e) {
            e.printStackTrace();
        }   
    }
}

服務器日志：

INFO: date invalide
GRAVE: javax.faces.validator.ValidatorException: date dont figure in the database
at DAOKPI.CalendarValidator.validate(CalendarValidator.java:60)
at javax.faces.component.UIInput.validateValue(UIInput.java:1149)
at javax.faces.component.UIInput.validate(UIInput.java:967)
at javax.faces.component.UIInput.executeValidate(UIInput.java:1233)
at javax.faces.component.UIInput.processValidators(UIInput.java:698)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1214)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1214)
at javax.faces.component.UIForm.processValidators(UIForm.java:253)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1214)
at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1214)
at javax.faces.component.UIViewRoot.processValidators(UIViewRoot.java:1172)
at com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:76)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:409)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1

Answer 1

再次查看您的代碼，您將自己捕獲並在ValidatorException器中打印ValidatorException ！ 您不應該自己捕獲並記錄ValidatorException 。 您應該放手讓JSF捕獲並處理它，以便它可以相應地在消息組件中顯示它。

擺脫驗證器中的try塊，並將throws子句添加到validate()方法中。

@Override  
public void validate(FacesContext context, UIComponent component, Object value) throws ValidatorException {
    java.util.Date date2 = (java.util.Date) value;

    if (validateDate(date2)) {
        throw new ValidatorException(new FacesMessage("A valid date")); // Btw: I wonder how that makes sense... That's actually not a validation error.
    } else {
        throw new ValidatorException(new FacesMessage("date dont figure in the database"));
    } 
}   

Answer 2

除了@Balusc在他的回答中提到的驗證器中的問題之外，你應該使用PrimeFaces組件：

<p:calendar id="date1" value="#{bean.date1}" showOn="button"> 
    <f:validator validatorId="calendarValidator" />
    <p:ajax execute="date1" update="calendarmessage" />
</p:calendar>
<p:message id="calendarmessage" for="date1" />