前些日子看了一篇關(guān)于在Spring 2中整合DWR 2的文章《
AJAX, DWR and Spring》。最近，想動(dòng)手試一下，就下載其源代碼回來看看，依葫蘆畫瓢做了一遍。在運(yùn)行時(shí)，得到XML驗(yàn)證錯(cuò)誤。經(jīng)過一翻折騰，終于把問題解決。
Spring 2基于XML Schema的配置
眾所周知，Spring 2通過XML Schema配置方式極大地簡化的其配置，而且使得第三方擴(kuò)展變?yōu)榭赡堋Ｅ渲萌缦麓a所示：
<? xml version="1.0" encoding="UTF-8" ?>
< beans xmlns ="http://www.springframework.org/schema/beans"
xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation ="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd" >
<!-- <bean /> definitions here -->
</ beans >
清單1 applicationContext.xml不知大家有沒有想過spring-beans-2.0.xsd位置在那里？其實(shí)，大家可以用Eclipse打開Spring的jar包，展開META-INF，并雙擊打開其中的spring.schemas文件，內(nèi)容如下：
http\://www.springframework.org/schema/beans/spring-beans- 2.0 .xsd = org/springframework/beans/factory/xml/spring-beans- 2.0 .xsd
http\://www.springframework.org/schema/tool/spring-tool- 2.0 .xsd = org/springframework/beans/factory/xml/spring-tool- 2.0 .xsd
http\://www.springframework.org/schema/util/spring-util- 2.0 .xsd = org/springframework/beans/factory/xml/spring-util- 2.0 .xsd
http\://www.springframework.org/schema/aop/spring-aop- 2.0 .xsd = org/springframework/aop/config/spring-aop- 2.0 .xsd
http\://www.springframework.org/schema/lang/spring-lang- 2.0 .xsd = org/springframework/scripting/config/spring-lang- 2.0 .xsd
http\://www.springframework.org/schema/tx/spring-tx- 2.0 .xsd = org/springframework/transaction/config/spring-tx- 2.0 .xsd
http\://www.springframework.org/schema/jee/spring-jee- 2.0 .xsd = org/springframework/ejb/config/spring-jee- 2.0 .xsd
http\://www.springframework.org/schema/beans/spring-beans.xsd = org/springframework/beans/factory/xml/spring-beans- 2.0 .xsd
http\://www.springframework.org/schema/tool/spring-tool.xsd = org/springframework/beans/factory/xml/spring-tool- 2.0 .xsd
http\://www.springframework.org/schema/util/spring-util.xsd = org/springframework/beans/factory/xml/spring-util- 2.0 .xsd
http\://www.springframework.org/schema/aop/spring-aop.xsd = org/springframework/aop/config/spring-aop- 2.0 .xsd
http\://www.springframework.org/schema/lang/spring-lang.xsd = org/springframework/scripting/config/spring-lang- 2.0 .xsd
http\://www.springframework.org/schema/tx/spring-tx.xsd = org/springframework/transaction/config/spring-tx- 2.0 .xsd
http\://www.springframework.org/schema/jee/spring-jee.xsd = org/springframework/ejb/config/spring-jee- 2.0 .xsd
清單2 spring.schemas從以上的文件中，可以看出XML Sechema文件在類包中位置。
DWR 2.0 RC 2中的XML Schema文件
根據(jù)上面的描述，我打開DWR的jar包中spring.schemas文件，內(nèi)容如下：
http\://www.directwebremoting.org/schema/spring-dwr- 2.0 .xsd = org/directwebremoting/spring/spring-dwr- 2.0 .xsd
然后，按照上面的路徑打開spring-dwr-2.0.xsd文件，內(nèi)容如下：
<? xml version="1.0" encoding="UTF-8" standalone="no" ?>
<!-- 省略了版權(quán)信息 -->
< xsd:schema xmlns ="http://www.directwebremoting.org/schema/spring-dwr"
xmlns:xsd ="http://www.w3.org/2001/XMLSchema"
targetNamespace ="http://www.directwebremoting.org/schema/spring-dwr"
elementFormDefault ="qualified"
attributeFormDefault ="unqualified" >
<!-- 省略了具體的定義 -->
</ xsd:schema >
清單3 spring-dwr-2.0.xsd文件spring-dwr-2.0.xsd告訴我們，其名稱空間應(yīng)為“http://www.directwebremoting.org/schema/spring-dwr”，所以我們?cè)谂渲肧pring 2時(shí)，應(yīng)使用以上的名稱空間，如下面的代碼片段所示：
<? xml version="1.0" encoding="UTF-8" ?>
< beans xmlns ="http://www.springframework.org/schema/beans"
xmlns:dwr ="http://www.directwebremoting.org/schema/spring-dwr"
xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation ="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.directwebremoting.org/schema/spring-dwr http://www.directwebremoting.org/schema/spring-dwr-2.0.xsd" >
< dwr:configuration >
< dwr:convert class ="net.blogjava.max.pws.domain.Album" type ="bean" >
< dwr:exclude method ="photos" />
</ dwr:convert >
< dwr:convert class ="net.blogjava.max.pws.domain.Photo" type ="bean" >
< dwr:exclude method ="original, poster, thumb, full, album" />
</ dwr:convert >
</ dwr:configuration >
< bean id ="ajaxFacade"
class ="net.blogjava.max.pws.web.ajax.AjaxFacade" >
< dwr:remote javascript ="AjaxFacade" />
< property name ="personalWebSite" ref ="personalWebSite" />
</ bean >
</ beans >
清單3 ajaxContext.xmlWEB-INF/web.xml配置
通過上面的配置，我們可以省去dwr.xml配置，不過在web.xml配置dwr的Servlet時(shí)，要使用新的Servlet類。配置代碼片段如下：
< servlet >
< servlet-name > dwr </ servlet-name >
< servlet-class > org.directwebremoting.spring.DwrSpringServlet </ servlet-class >
< init-param >
< param-name > debug </ param-name >
< param-value > true </ param-value >
</ init-param >
< load-on-startup > 1 </ load-on-startup >
</ servlet >
< servlet-mapping >
< servlet-name > dwr </ servlet-name >
< url-pattern > /dwr/* </ url-pattern >
</ servlet-mapping >
清單4 web.xml總結(jié)
通過在Spring 2整合DWR 2配置，可以集中管理應(yīng)用程序的配置，從一定程度上解決JavaEE開發(fā)中的配置文件泛濫的問題。
