Struts 2 Reading Notes-Use of wildcards

  Configure  action  ,   struts. XML     
    
     ... /> The vast majority of 
      are the same. In this case, we can use the  struts 2 
      provided  wildcard ing mechanism to solve this problem. 
     

in .... /> , you can specify name use a pattern string (that is, use" * " to replace one or more arbitrary characters ), next, you can class , method attributes and ... /> in use {n } to represent the first few * represents a character.

1. When we go to action name If a wildcard is used in an attribute, you can use elements replace multiple logics Action .

1 <ActionName= "* Action"Class= "Com. App. Action. loginaction"Method= "{1 }">
 

A series of logical actions are defined above. . That is, as long as the user requests Url = * Action Mode, you can use this Action . For Method Attribute, which is: {1} . Indicates that the value of this expression is Name The first attribute in the attribute value * . For example URL Is Registaction . Call Registaction Class Regist Method.

2. class attributes can also be used {n } expression. That is, struts 2 A series of action Configure to a element. Equivalent to the element is configured with multiple logics action

1 <ActionName= "* Action"Class= "Com. App. Action. {1} action">
 

 

  The above Struts. xml Medium Class Attribute value used {N} Format expression. This expression indicates: If RUL Is Loginaction Request, the first of which is * Is Login , That is Action The processing class is Loginaction . Specifies the processing method as the default execute () method.

 Based on the above description: you can determine the followingStruts. xmlConfiguration

 
1 <ActiionName= "*_*"Method= "{1 }"Class= "Com. App. Actions. {2 }" >
 

    The aboveAction  The mode is  **_*  So all requests that match this mode can be  Action  Processing. If one  URL  Is  Regist_login.action  . Because it matches  *_*  Request, and the first  *  Is  Regist  , The second is Login  . It means to call  Com. App. Action. Login  Processing class  Regist  Method to process this request. 

 

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