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JSF教程 – JSF自定义验证器示例
我们可以在JSF中创建自己的自定义验证器。
以下列表包含我们在JSF中创建自定义验证器时可以遵循的步骤。
- 通过实现javax.faces.validator.Validator接口创建一个验证器类。
- 实现上述接口的validate()方法。
- 使用注释@FacesValidator为自定义验证器分配唯一的ID。
例子
以下代码来自EmailValidator.java。
package cn.w3cschool.common;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.faces.application.FacesMessage;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.validator.FacesValidator;
import javax.faces.validator.Validator;
import javax.faces.validator.ValidatorException;
@FacesValidator("cn.w3cschool.common.EmailValidator")
public class EmailValidator implements Validator{
private static final String EMAIL_PATTERN = "^[_A-Za-z0-9-]+(\\." +
"[_A-Za-z0-9-]+)*@[A-Za-z0-9]+(\\.[A-Za-z0-9]+)*" +
"(\\.[A-Za-z]{2,})$";
private Pattern pattern;
private Matcher matcher;
public EmailValidator(){
pattern = Pattern.compile(EMAIL_PATTERN);
}
@Override
public void validate(FacesContext context, UIComponent component,
Object value) throws ValidatorException {
matcher = pattern.matcher(value.toString());
if(!matcher.matches()){
FacesMessage msg =
new FacesMessage("E-mail validation failed.",
"Invalid E-mail format.");
msg.setSeverity(FacesMessage.SEVERITY_ERROR);
throw new ValidatorException(msg);
}
}
}
以下代码来自demo.xhtml。
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core">
<h:body>
<h:form>
<h:panelGrid columns="3">
Enter your email :
<h:inputText id="email" value="#{user.email}"
size="20" required="true" label="Email Address">
<f:validator validatorId="cn.w3cschool.common.EmailValidator" />
</h:inputText>
<h:message for="email" style="color:red" />
</h:panelGrid>
<h:commandButton value="Submit" action="result" />
</h:form>
</h:body>
</html>
以下代码来自result.xhtml。
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
>
<h:body>
<h1>Custom validator in JSF 2.0</h1>
<h:panelGrid columns="2">
Email Address :
<h:outputText value="#{user.email}" />
</h:panelGrid>
</h:body>
</html>
下面的代码来自UserBean.java。
package cn.w3cschool.common;
import java.io.Serializable;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
@ManagedBean(name="user")
@SessionScoped
public class UserBean implements Serializable{
private static final long serialVersionUID = 1L;
String email;
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}
下载 Custom-Validator.zip
运行
将生成的WAR文件从目标文件夹复制到Tomcat部署文件夹，并运行Tomcat-Install-folder/bin/startup.bat。
Tomcat完成启动后，在浏览器地址栏中键入以下URL。
http://localhost:8080/simple-webapp/demo.xhtml
