nanocontainer-struts 的简单应用

类别:Java 点击:0 评论:0 推荐:

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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