Java开发网 - 求助:为什么没有去调用 ActionForm 中 Validate 的方法?

Topic: 求助:为什么没有去调用 ActionForm 中 Validate 的方法?

1.求助:为什么没有去调用 ActionForm 中 Validate 的方法?

Posted by: ntshenwh
Posted on: 2005-12-04 15:00

大家好,我遇到个奇怪的问题,请大家帮忙解释一下:
1)------------------ struts-config.xml -----------------------------------
<?xml version="1.0" encoding="ISO-8859-1" ?>
<!DOCTYPE struts-config PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 1.0//EN"
"http://jakarta.apache.org/struts/dtds/struts-config_1_0.dtd">

<struts-config>

  <form-beans>
    <form-bean name="userForm" type="mypackage.UserForm"/>    </form-beans>

  <global-forwards>
    <forward name="userCreated" path="/viewUser.jsp"/>
    <forward name="userCreatedError" path="/createUserError.jsp"/>
  </global-forwards>

  <action-mappings>
    <action path="/createUser"
     type="mypackage.UserAction"
     name="userForm"
     scope="request"
     validate="true"
     input="/createUser.jsp">
    </action>
  </action-mappings>

  <message-resources parameter="ApplicationResources"/>
</struts-config>

2)-------------------- UserAction.java ------------------------------
package mypackage;

import org.apache.struts.action.*;
import javax.servlet.http.*;

public class UserAction extends Action
{
  public ActionForward perform(ActionMapping mapping,ActionForm form,HttpServletRequest request,HttpServletResponse response)
  {
    // get data from actionform
    UserForm f = (UserForm)form;

    // call actionform's validate
    ActionErrors errors = f.validate(mapping,request) ;

   if ( errors != null)
   {
     if ( errors.size()>0)
     {
       System.out.println("Exist error, will navigate to error page");
       request.setAttribute("errors",errors);
       return (mapping.findForward("userCreatedError"));     }

   }

    try
    {

      UserBean bean = new UserBean();
      bean.addUser(f.getUser());

    }
    catch(Exception e)
    {
      e.printStackTrace();
    }

    request.setAttribute("User",f.getUser());
    return (mapping.findForward("userCreated"));
  }
}

3)---------------------------- UserForm.java------------------------
package mypackage;

import javax.servlet.http.HttpServletRequest;
import org.apache.struts.action.*;

public class UserForm extends ActionForm
{
  private User user = new User();

  public void setUser(User u)
  {
    this.user = u;
  }
  public User getUser()
  {
    return this.user;
  }

  public void setUserName(String username)
  {
    user.setUserName(username);
  }
  public String getUserName()
  {
    return user.getUserName();
  }

  // reset form
  public void reset(ActionMapping mapping,HttpServletRequest request)
  {
    this.user = new User();
  }

  // validate
  public ActionErrors Validate(ActionMapping mapping,HttpServletRequest request)  {
    ActionErrors errors = new ActionErrors();

    System.out.println("The password's legnth is " + this.user.getPassword().length());

    if (this.user.getUserName()==null)
    {
      errors.add("UserName",new ActionError("User name should not be empty"));
    }
    if (this.user.getPassword().length()<3 )
    {
      System.out.println("Find a error");
      errors.add("Password",new ActionError("Password's length should be larger than 3"));
    }
    return errors;
  }
}

4)--------------------- createUser.jsp ---------------------------
<%@ page contentType="text/html;charset=gb2312" %>
<%@ taglib uri="/struts-logic" prefix="logic" %>
<%@ taglib uri="/struts-bean" prefix="bean" %>
<%@ taglib uri="/struts-html" prefix="html" %>

<html:html locale="true">
<head>
<html:base/>
<title>
<bean:message key="index.title"/>
</title>
</head>
<body>
<h2>´´½¨Ò»¸öÓÃ»§£º</h2>
<html:errors/>

<html:form action="createUser.do" method="get">

UserName;<html:text property="user.userName"/><br/>
Password:<html:password property="user.password"/><br/>
Age:<html:text property="user.age"/><br/>
<html:submit property="submit"/>

</html:form>
</body>
</html:html>

5)------------------------------------ createUserError.jsp----------------------
<%@ page contentType="text/html;charset=gb2312" import="mypackage.User,org.apache.struts.action.*" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jstl/core" %>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jstl/fmt" %>
<%@ taglib uri="/struts-logic" prefix="logic" %>
<%@ taglib uri="/struts-bean" prefix="bean" %>
<%@ taglib uri="/struts-html" prefix="html" %>

<html:html locale="true">
<head>
<html:base/>
<title>
<bean:message key="index.title"/>
</title>
</head>
<body>

<h2>The Errors is :</h2>
<c:forEach var="err" items="${errors}">
  <c:out value="${err.toString()}"/><br>
</c:forEach>

</body>
</html:html>

(注意下划线部分)
问题是, 我在 createUser.jsp 中, password 只输入2个字符(也就是不应该验证通过) 提交后,并没有按照我所想的那样转到 createdUserError.jsp ?

2.Re:求助:为什么没有去调用 ActionForm 中 Validate 的方法? [Re: ntshenwh]	Copy to clipboard
Posted by: ntshenwh Posted on: 2005-12-05 12:22 麻烦哪位高手帮我看看，是不是我不应该这么写？谢谢

3.Re:求助:为什么没有去调用 ActionForm 中 Validate 的方法? [Re: ntshenwh]

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Posted by: bigfoot007
Posted on: 2005-12-06 16:49

这个结果是肯定的，当你调用Validate（）时，如果返回的errors不为空则，直接返回配置文件中的Input所指定的jsp文件，而不再继续执行action中的perform（）函数。你仔细研究一下struts的工作原理，就明白了。

如果你想在页面中显示你的错误提示信息，可以将提示错误的代码写入你的createUser.jsp 中，也就是将你的createUserError.jsp中的代码合并到createUser.jsp中。

4.Re:求助:为什么没有去调用 ActionForm 中 Validate 的方法? [Re: bigfoot007]	Copy to clipboard
Posted by: ntshenwh Posted on: 2005-12-06 18:07 Thanks bigfoot007 for your kindlly helps good luck