📄 入門 15 - 使用dispatchaction類別 - javaworld@tw.htm
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<DIV class=pageheader><SPAN class=pagetitle>入門 15 -
使用DispatchAction類別</SPAN> </DIV>
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<DIV class=pagesubheading>Last changed on Oct 27, 2004 by <A
href="http://www.javaworld.com.tw/confluence/display/~koji">koji
lin</A>
</DIV><!-- page content --> 在之前的主題中，您為每一個動作撰寫一個Action類，隨著網站的增大，維護Action的成本也就隨著增大，您可以使用模組化來管理，而另一方面，在檢視一些Action時，您會發現某些Action所執行的，其實是完成一個業務邏輯所需要的連續動作或相關動作，例如帳號的登入、登出等動作。<BR> 在Struts中，您可以使用org.apache.struts.actions.DispatchAction類別將完成一個業務邏輯所需要的連續動作或相關動作集中於一個Action類中，在繼承DispatchAction後，您不再是重新定義execute()方法，而是撰寫自己的動作，execute()方法是在DispatchAction抽象類定義
的。<BR> 例如我們可以繼承DispatchAction來定義一個AccountAction，在當中集中管理一些與帳號相關的操作，一個例子如下：
<DIV class=code
style="BORDER-TOP-STYLE: solid; BORDER-RIGHT-STYLE: solid; BORDER-LEFT-STYLE: solid; BORDER-BOTTOM-STYLE: solid">
<DIV class=codeHeader
style="BORDER-BOTTOM-STYLE: solid"><B>AccountAction.java</B></DIV>
<DIV class=codeContent><PRE><SPAN class=java-keyword>package</SPAN> onlyfun.caterpillar;
<SPAN class=java-keyword>import</SPAN> javax.servlet.http.*;
<SPAN class=java-keyword>import</SPAN> org.apache.struts.action.*;
<SPAN class=java-keyword>import</SPAN> org.apache.struts.actions.*;
<SPAN class=java-keyword>public</SPAN> class AccountAction <SPAN class=java-keyword>extends</SPAN> DispatchAction {
<SPAN class=java-keyword>public</SPAN> ActionForward login(ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response)
<SPAN class=java-keyword>throws</SPAN> Exception {
<SPAN class=java-comment>// 進行一些Login的邏輯</SPAN>
......
}
<SPAN class=java-keyword>public</SPAN> ActionForward logout(ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response)
<SPAN class=java-keyword>throws</SPAN> Exception {
<SPAN class=java-comment>// 進行一些Logout的邏輯</SPAN>
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