关于struts-config里action元素里的attribute属性用途的理解

Tue, 06 Feb 2007 08:51:00 GMT

action mapping中的attribute 属性到底是�q�什么用�? 很早以前一直不太了�?今天�H�然又想��C��q�个问题,感觉不能再扔一边不��了, 一定要解决�?

�q�是在网上查到的关于attribute的解�?
1�Q�应用前提，attribute只有在设�|�了name后才有意义�?br />2�Q�attribute可以实现对象的重用，卛_��果设�|�了attribute属性，在创建actionform是，会先��L��扄��应的scope中是否有此对象，如果有，则重用，否则创徏新的对象�?br />3�Q�当你将创徏的acitonForm保存到相应的scope中时�Q�你想用一个更有意义的名字来访问它�Ӟ��它就有意义了�?br />
可是,看到"一个更有意义的名字的时�?, 我好像有点理解了
attribute="newLoginForm"
name="loginForm"
type="loginAction"
scope="request"
path="/login">

在struts实例化actionform的时�?struts是根据attribute的值来查找�q�创建actionform�Q�有两种情况�Q�如果已�l�存在，那么从内存中取回�Q�如果第一�ơ实例化�Q�那么创建，�q�放入内存�?br />

org.apache.struts.util.RequestUtils中的源代�?br />
   public static Actionform createActionform(
HttpServletRequest request,
ActionMapping mapping,
ModuleConfig moduleConfig,
ActionServlet servlet) {
       ............
      ............

       String attribute = mapping.getAttribute();
      ......
       Actionform instance = null;
HttpSession session = null;

       if ("request".equals(mapping.getScope())) {
instance = (Actionform) request.getAttribute(attribute);
} else {
session = request.getSession();
instance = (Actionform) session.getAttribute(attribute);
}
      ................
        ................

       }

如果没有配置attribute属性的�? struts才会从name属性里��d��要创建的formbean 的名�?�q�创��Z��下实�?看下边的源代码就知道�? 呵呵.

org.apache.struts.config.ActionConfig

   protected String attribute = null;

public String getAttribute() {
//��是�q�里�?
if (this.attribute == null) {
return (this.name);
} else {
return (this.attribute);
}
}

public void setAttribute(String attribute) {
if (configured) {
throw new IllegalStateException("Configuration is frozen");
}
this.attribute = attribute;
}

赉|��?/a> 2007-02-06 16:51 发表评论

Tue, 06 Feb 2007 05:34:00 GMT

�W�一�?在struts-config文�g里添加valudator插�g

在action配置里添加属�?br /> validate="true"

�W�二�?

在validation.xml文�g里添加要验证的表单字�D늚�信息

在资源文仉��d��

validation.test.title=struts validation test
errors.required={0} is required.

errors.minlength={0} can not be less than {1} characters.

errors.maxlength={0} can not be greater than {1} characters.

errors.invalid={0} is invalid.

errors.byte={0} must be an byte.
errors.short={0} must be an short.
errors.integer={0} must be an integer.
errors.long={0} must be an long.
errors.float={0} must be an float.
errors.double={0} must be an double.

errors.date={0} is not a date.
errors.range={0} is not in the range {1} through {2}.
errors.creditcard={0} is not a valid credit card number.
errors.email={0} is an invalid e-mail address.

LogonForm.ipcode=User name
LogonForm.password=User password

�{�等你所惌��d��的信�?br />

赉|��?/a> 2007-02-06 13:34 发表评论

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关于struts-config里action元素里的attribute属性用途的理解