4.使用Spring的ActionSupport类
要用Spring去集成Struts,创建一个Spring 上下文是必须要做的。 org.springframework.web.struts.ActionSupport 类提供一个 getWebApplicationContext() 方法非常容易地获得Spring上下文,全部你需要去做的是从Spring的ActionSupport 代替Struts 中的Action类去延伸你的action,如下所示:
package com.infotek.Creditcard.actions; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.struts.action.ActionError; import org.apache.struts.action.ActionErrors; import org.apache.struts.action.ActionForm; import org.apache.struts.action.ActionForward; import org.apache.struts.action.ActionMapping; import org.apache.struts.action.DynaActionForm; import org.springframework.context.ApplicationContext; import org.springframework.web.struts.ActionSupport; import com. infotek.Creditcard.beans.Creditcard; import com. infotek.Creditcard.business.CreditcardService; public class SearchSubmit extends ActionSupport { |(1) public ActionForward execute(ActionMapping mapping,ActionForm form, HttpServletRequest request,HttpServletResponse response) throws IOException, ServletException { DynaActionForm searchForm = (DynaActionForm) form; String isbn = (String) searchForm.get("cardno"); //the old fashion way //CreditcardService creditcardService = new CreditcardServiceImpl(); ApplicationContext ctx = getWebApplicationContext(); |(2) CreditcardService creditcardService = (CreditcardService ) ctx.getBean("creditcardService"); |(3) CreditCard creditard = CreditCardService.read(cardno.trim()); if (null == creditard) { ActionErrors errors = new ActionErrors(); errors.add(ActionErrors.GLOBAL_ERROR,new ActionError ("message.notfound")); saveErrors(request, errors); return mapping.findForward("failure") ; } request.setAttribute("creditcard", creditcard); return mapping.findForward("success"); } } |
在(1)中,我们 通过延伸Spring ActionSupport 类而不是Struts Action 类创建了一个action;在(2)中,我们使用getWebApplicationContext()方法获得一个ApplicationContext;为了获得商务服务,在(3)中,我们使用ApplicationContext去查找Spring bean;这个技术非常容易理解,不幸的是它把Struts的action和Spring framework绑定了,如果你想替换Spring你不得不重写代码,而且Struts的action不在Spring的控制之下,遗憾的是这种方法无法获得Spring AOP的好处。
5.结论
本文我们尝试使用Spring的ActionSupport,ContextLoaderPlugIn去集成Struts,这是一种最高效的和最简单的方式,另外还可用Spring中的代理子类去代理Struts中的RequestProcessor和代理Struts的actions。