Struts中DispatchAction类的使用

今天刚刚看了DispatchAction觉得这个东西有点意思,所以就写点东西,通过它的名字我想应该可以明白它的作用了,用于分发的Action,主要的好处是把一些功能类似的Action放到一个Action中，通过传入的不同参数来觉得执行哪个操作.
    DispatchAction类是一个抽象类,它实现了父类(Action)的execute()方法,所以它的子类就不用来实现这个方法了，只需要专注与实际操作的方法,
     1.首先要一个DispatchAction的子类,它含有一些方法,login,logout,method1,
package examples;
                                                                               
package examples;
                                                                               
import javax.servlet.http.*;
import org.apache.struts.action.*;
import org.apache.struts.actions.*;



public class AccountAction extends DispatchAction {
    public ActionForward login(ActionMapping mapping,
                              ActionForm form,
                              HttpServletRequest request,
                              HttpServletResponse response)
    throws Exception {
        // 進行一些Login的邏輯
              return mapping.findForward("success");  

    }
                                                                               
    public ActionForward logout(ActionMapping mapping,
                                ActionForm form,
                                HttpServletRequest request,
                                HttpServletResponse response)
    throws Exception {
        // 進行一些Logout的邏輯
              return mapping.findForward("success1");  

    }

    public ActionForward method1(ActionMapping mapping,
                                ActionForm form,
                                HttpServletRequest request,
                                HttpServletResponse response)
    throws Exception {
        // 進行一些method1的邏輯
              return mapping.findForward("success");  

    }

    
}


 
      一定要注意在DispatchAction中你想执行的操作,都必须要有统一的参数(ActionMapping mapping, ActionForm form,HttpServletRequest request, HttpServletResponse response),是一个规定.
2.接下来是配置struts-config.xml
 
    <action path="/login"  type="examples.AccountAction" 
             name="logonForm"
             scope="request"
             parameter="action"
             input="/pages/dispatch1.jsp">
       <forward name="success" path="/pages/success.jsp" />
    </action>

    <action path="/logout"  type="examples.AccountAction" 
             name="logonForm"
             scope="request"
             parameter="action"
             input="/pages/dispatch1.jsp">
       <forward name="success1" path="/pages/success1.jsp" />
    </action>

   这里需要注意的就是parameter属性的值,因为这个值要和页面传来的参数对应.

3.再来看看JSP页 pages/dispatch1.jsp
 
<%@ taglib uri="/tags/struts-html" prefix="html" %>
<html:link href="/DispathActionTest/login.do?action=login">login</html:link><br>
<html:link href="/DispathActionTest/logout.do?action=logout">logout</html:link>


    这里要注意几点,首先 ?后面的KEY要和struts-config.xml中的parameter相同,还有它的VALUE要是你在action的一个方法名字,这里方法名为login, 那么在程序运行时就是调用login的操作,如果是logout,那程序就调用logout的操作.