提交的输入值为null时，不调用JSF定制验证器 [英] JSF custom validator not invoked when submitted input value is null

问题描述

我创建了一个自定义验证器，当输入为null时不会被调用.

I created a custom validator which is not getting called when input is null.

我的验证者代码:

@FacesValidator("requiredValidator")
public class RequredValidation implements Validator {

    public void validate(FacesContext context, UIComponent component,
            Object value) throws ValidatorException {
        System.out.println("in valid GGGGGGGG");

    }

我的xhtml页面代码:

My xhtml page code:

<p:message for="urlInput"  />

<p:inputText id="urlInputv" value="#{coverageBean.firstname}" label="URL" maxlength="2" >
    <f:validator validatorId="requiredValidator"></f:validator>
</p:inputText>
<p:message for="urlInputv"  />
<p:commandButton value="submit" action="#{loginBean.validateText}" />

现在，当我在文本框中输入任何值时，此方法有效，但当inputtext为null时，此方法无效.

Now this is working when I am entering any value in text box, but it is not working when inputtext is null.

服务器正在使用

• Tomcat
• primefaces 3.5
• jsf2.0

请问任何人有什么问题吗?

Please could anyone tell what the problem is?

推荐答案

默认情况下，如果Bean验证(JSR303)在环境中不可用，则JSF不会验证空的提交值.可以使用上下文参数javax.faces.VALIDATE_EMPTY_FIELDS来控制此行为.

By default, JSF does not validate an empty submitted value if Bean Validation (JSR303) is not available in the environment. This behavior can be controlled with the context parameter javax.faces.VALIDATE_EMPTY_FIELDS.

javax.faces.VALIDATE_EMPTY_FIELDS的默认值为auto，这意味着如果类路径中有Bean验证(JSR303)可用，则空字段将得到验证.

The default value for javax.faces.VALIDATE_EMPTY_FIELDS is auto, meaning that empty fields are validated if Bean Validation (JSR303) is available in the class path.

如果无论如何都想在没有Bean验证的情况下验证空字段，则可以像下面这样在web.xml中将context参数显式设置为true:

If you want to validate empty fields anyway without Bean Validation, then explicitly set the context parameter in your web.xml to true like this:

<context-param>
    <param-name>javax.faces.VALIDATE_EMPTY_FIELDS</param-name>
    <param-value>true</param-value>
</context-param>

必须说，如果要根据需要验证输入字段，通常使用required="true".然后，您无需在自定义验证器中执行该工作.

It must be said that you normally use required="true" in case you want to validate an input field as required. You don't need to perform that job in your custom validator then.

<p:inputText ... required="true" requiredMessage="Please enter value" />

或者，用<f:validateRequired>更抽象:

<p:inputText ... requiredMessage="Please enter value">
    <f:validateRequired />
</p:inputText>

请注意，您可以在同一输入组件上安全地使用多个验证器.

Do note that you can safely use multiple validators on the very same input component.

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