nanocontainer对picocontainer容器作了一些扩充的包装,它提供了用多种脚本(groovy, .bsh, .js, .py or .xml等)配置容器管理的对象的功能,同时提供了对web容器的支持,并且针对struts、webwork也有专门的支持,这里我调试成功了在struts中如何使用nanocontainer容器。nanocontainer的网站上的文档提供的非常少,从这里可以下载到一个简单的web应用的例子。 http://dist.codehaus.org/nanocontainer/war/nanocontainer-sample-nanowar.war 但是这个war并不完整,解开war看到只有一些编译过的class,要看源代码可以从cvs上下载到 http://www.nanocontainer.org/Source+Repositories 并没有web.xml struts-config.xml等配置文件和jsp文件。nanocontainer也太不注重文档和例子代码的详细程度了。我自己补充完整了这个例子需要的其他文件,在下面贴出来。 运行这个例子需要以下几个文件: 1. web.xml 这个文件只要从struts提供的例子中的blank中找到一个空的web.xml文件,加入下面配置就可以了 <context-param> <param-name>nanocontainer.groovy</param-name> <param-value>/WEB-INF/nanocontainer.groovy</param-value> </context-param>
<listener> <listener-class>org.nanocontainer.nanowar.ServletContainerListener</listener-class> </listener>
2.nanocontainer.groovy 放到/WEB-INF中,我在这里使用了groovy 脚本的配置方式。 pico = new org.picocontainer.defaults.DefaultPicoContainer(parent) if(assemblyScope instanceof javax.servlet.ServletContext) { pico.registerComponentImplementation(org.nanocontainer.sample.nanowar.service.defaults.DefaultCheeseService) pico.registerComponentImplementation(org.nanocontainer.sample.nanowar.dao.simple.MemoryCheeseDao) } else if(assemblyScope instanceof javax.servlet.http.HttpSession) {
} else if(assemblyScope instanceof javax.servlet.ServletRequest) {
}
3.struts-config.xml文件内容如下 <?xml version="1.0" encoding="ISO-8859-1" ?>
<!DOCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 1.1//EN" "http://jakarta.apache.org/struts/dtds/struts-config_1_1.dtd">
<struts-config>
<!-- ============================================ Data Source Configuration -->
<!-- ================================================ Form Bean Definitions -->
<form-beans> <form-bean name="inputForm" type="org.nanocontainer.sample.nanowar.struts.CheeseForm"/>
</form-beans>
<!-- ========================================= Global Exception Definitions -->
<global-exceptions> <!-- sample exception handler <exception key="expired.password" type="app.ExpiredPasswordException" path="/changePassword.jsp"/> end sample --> </global-exceptions>
<!-- =========================================== Global Forward Definitions -->
<global-forwards> <!-- Default forward to "Welcome" action --> <!-- Demonstrates using index.jsp to forward -->
<!-- =========================================== Action Mapping Definitions -->
<action-mappings> <action path="/nanicoTest" type="org.nanocontainer.sample.nanowar.struts.CheeseAction" name="inputForm" >
<forward redirect="false" name="next" path="/result.jsp" /> </action>
</action-mappings>
<!-- ============================================= Controller Configuration -->
<controller processorClass="org.nanocontainer.nanowar.struts.PicoRequestProcessor"/>
<!-- ======================================== Message Resources Definitions -->
<message-resources parameter="MessageResources" />
</struts-config>
4. naoweb.jsp 一个测试的jsp form表单页面。
<%@ page language="java" contentType="text/html;charset=UTF-8"%>
<%@ taglib uri="http://jakarta.apache.org/struts/tags-bean" prefix="bean" %> <%@ taglib uri="http://jakarta.apache.org/struts/tags-html" prefix="html" %> <%@ taglib uri="http://jakarta.apache.org/struts/tags-logic" prefix="logic" %> <%@ taglib uri="http://jakarta.apache.org/struts/tags-tiles" prefix="tiles" %> <%@ taglib uri="http://jakarta.apache.org/struts/tags-nested" prefix="nested" %> <% out.println(session.getAttribute(org.apache.struts.Globals.LOCALE_KEY)+"--<br>"); %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html:html locale="true"> <head> <html:base /> <title>zmlogin.jsp</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> </head> <body>
<html:errors/>
<html:form action="nanicoTest"> <INPUT type="hidden" name="method" value="vtest"> <table width="41%" border="1"> <tr> <td width="26%">Name</td> <td width="74%"><input type="text" name="name"></td> </tr> <tr> <td>Country</td> <td><input type="text" name="country"></td> </tr>
<tr> <td colspan="2"><div align="center"> <input name="submit" type="submit"> </div></td> </tr> </table> <br> </html:form> </body> </html:html>
5.提交的结果页面 result.jsp <% out.println("=="+request.getAttribute("cheesesOfTheWord")); %>
将这几个文件保存,放到合适的位置,启动tomcat,请求naoweb.jsp文件即可。 我们可以从源码CheeseAction看到,CheeseService 是个接口,这个代码中并没有给出接口的实现, 并没有和某一个具体的实现产生依赖关系,可见依赖关系是在运行时由容器建立的,pico容器使用的是构造子注入,可以看到代码中有对应的构造器。容器是从nanocontainer.groovy配置文件中找到具体实现的。然而代码是可以正常运行的,这就是我们想要达到的理想的效果,真正的面向接口的编程。这样的结果对我们的单元测试是非常有利的。 public class CheeseAction extends Action {
private final CheeseService cheeseService;
public CheeseAction(CheeseService cheeseService) { this.cheeseService = cheeseService; }
public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception { CheeseForm cheeseForm = (CheeseForm) form;
if (!isEmpty(cheeseForm.getName())) { Cheese cheese = new Cheese(cheeseForm.getName(), cheeseForm.getCountry()); cheeseService.save(cheese); }
Collection cheeses = cheeseService.getCheeses(); request.setAttribute("cheesesOfTheWord", cheeses);
return mapping.findForward("next"); }
private boolean isEmpty(String s) { return s == null || "".equals(s.trim()); }
}

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