解决struts2中validation.xml配置无效的问题，我使用了xml的验证，却始终发现无法生效，后面发现才是xml的头文件的格式问题，修改了一下就好了。


成功的xml

<!DOCTYPE validators PUBLIC
        "-//Apache Struts//XWork Validator 1.0.2//EN"
        "http://struts.apache.org/dtds/xwork-validator-1.0.2.dtd">
<validators>
  <field name="username">
      <field-validator type="requiredstring">
          <message>You must enter a value for bar.</message>
      </field-validator>
  </field>
</validators>


主要是<!DOCTYPE validators PUBLIC


        "-//Apache Struts//XWork Validator 1.0.2//EN"


        "http://struts.apache.org/dtds/xwork-validator-1.0.2.dtd">

这句话的格式要正确，否则就无法生效了。


如何利用validation.xml进行验证的步骤如下：


1、写一个ValideAction.java，也就是处理业务逻辑的类

package com.test.action;

import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.ModelDriven;
import com.test.model.Contact;
import com.test.model.User;

public class ValideAction extends ActionSupport implements ModelDriven<User>{

  /**
   * 
   */
  private static final long serialVersionUID = 1L;
  
  private User user;
  private String username;
  private Contact contact;
  
  
  
  public Contact getContact() {
    return contact;
  }

  public void setContact(Contact contact) {
    this.contact = contact;
  }

  public String getUsername() {
    return username;
  }

  public void setUsername(String username) {
    this.username = username;
  }

  public String getPassword() {
    return password;
  }

  public void setPassword(String password) {
    this.password = password;
  }

  private String password;
  
  public String execute()
  {
    //System.out.println(user.getContact().getPhone());
    return SUCCESS;
  }

  @Override
  public User getModel() {
    // TODO Auto-generated method stub
    if (null == user) {
         return user = new User();
        }
        return user;
  }

}


2、编写一个验证文件，ValideAction-validation.xml

<!DOCTYPE validators PUBLIC
        "-//Apache Struts//XWork Validator 1.0.2//EN"
        "http://struts.apache.org/dtds/xwork-validator-1.0.2.dtd">
<validators>
  <field name="username">
      <field-validator type="requiredstring">
          <message>You must enter a value for bar.</message>
      </field-validator>
  </field>
</validators>


3、对应的JSP页面，注意，我这里只用了一个username作为测试判断的例子，其他字段例如password没有用来测试。

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib uri="/struts-tags" prefix="s"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<!-- 这个地方是用来显示错误信息 -->
<s:fielderror/>
<form action="data.action" method="post">
用户名：<input type="text" name="username"><br>
密码：<input type="password" name="password"><br>
-------------------联系方式----------------<br>
手机：<input type="text" name="contact.phone"><br>
地址：<input type="text" name="contact.address"><br>
邮箱：<input type="text" name="contact.email"><br>


<input type="submit" name="ok"><br>
</form>
</body>
</html>


4、struts.xml中配置action

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
  "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
  "http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>

    
  <!--   采用注解的方式 -->
  
    <constant name="struts.enable.DynamicMethodInvocation" value="true" />
    <constant name="struts.devMode" value="true" /> 

    <package name="default" namespace="" extends="struts-default">
      <!-- 正确和错误的分别跳转，input是在验证失败后会跳转的页面 -->
      <action name="data" class="com.test.action.ValideAction"> 
           <result name="success">/result.jsp</result>
          <result name="input">/login.jsp</result>
      </action>
    </package>

   
    <!-- Add packages here -->

</struts>


5、最终显示JSP页面就是上面那个文件，主要用<s:fielderror/>来显示错误信息

6、文件目录结构

解决struts2中validation.xml配置无效的问题_html


输出结果

解决struts2中validation.xml配置无效的问题_xml_02