Spring DM 1.1.x的最大特性便是它可以支持在其中部署WEB应用,我使用后感觉这是个很酷的特性,我甚至觉得用这种方式开发基于OSGi WEB应用比使用Spring DM Server更好,至少目前你可以获得更好的便携性(可以在多个Spring DM支持的OSGi平台上运行),并且Spring DM Server并没有提供更多的企业应用支持。
不过对于刚使用Spring DM进行WEB应用开发的人来说,成功地配置却不是一件容易的事。以下详细的讲解一下相关配置。
1 运行环境所需的Bundles:
0 ACTIVE system.bundle_3.2.2.R32x_v20070118
1 ACTIVE com.springsource.slf4j.api_1.5.0
2 RESOLVED org.springframework.osgi.jetty.web.extender.fragment.osgi_1.0.0
Master=46
3 ACTIVE org.springframework.bundle.osgi.extender_1.0.1.v200803070100
4 ACTIVE org.springframework.bundle.spring.core_2.5.5
5 ACTIVE org.springframework.bundle.spring.web_2.5.5
6 ACTIVE com.springsource.org.objectweb.asm_2.2.3
7 RESOLVED osgi_log_config_1.0.0
Master=36
8 ACTIVE org.springframework.bundle.osgi.core_1.0.1.v200803070100
9 ACTIVE com.springsource.slf4j.log4j_1.5.0
10 ACTIVE org.springframework.bundle.spring_2.5.2.v200803070100
11 ACTIVE org.springframework.bundle.spring.context_2.5.5
12 ACTIVE javax.servlet_2.4.0.v200706111738
13 ACTIVE org.springframework.osgi.servlet-api.osgi_2.5.0.SNAPSHOT
14 ACTIVE com.springsource.net.sf.cglib_2.1.3
15 ACTIVE org.springframework.bundle.spring.beans_2.5.5
16 ACTIVE javax.servlet.jsp_2.0.0.v200706191603
18 ACTIVE org.springframework.osgi.jetty.start.osgi_1.0.0
19 ACTIVE org.springframework.bundle.osgi.io_1.0.1.v200803070100
20 ACTIVE org.aopalliance_1.0.0
21 ACTIVE org.springframework.bundle.spring.context.support_2.5.5
23 ACTIVE com.springsource.org.aopalliance_1.0.0
24 ACTIVE org.springframework.bundle.spring.aop_2.5.5
25 ACTIVE com.springsource.slf4j.org.apache.commons.logging_1.5.0
30 ACTIVE org.objectweb.asm_2.2.3
33 ACTIVE org.mortbay.jetty.server_6.1.9
35 ACTIVE org.mortbay.jetty.util_6.1.9
36 ACTIVE org.springframework.osgi.log4j.osgi_1.2.15.SNAPSHOT
Fragments=7
37 ACTIVE org.mortbay.jetty_5.1.11.v200706111724
43 ACTIVE org.springframework.bundle.osgi.extender_1.1.2
44 ACTIVE org.springframework.bundle.osgi.io_1.1.2
45 ACTIVE org.springframework.bundle.osgi.web_1.1.2
46 ACTIVE org.springframework.bundle.osgi.web.extender_1.1.2
Fragments=2
47 ACTIVE org.springframework.bundle.osgi.core_1.1.2
以上这些Bundles可以在spring dm 1.1.2的发布包中找到,以上Bundles的start level设置为2。
2 加入Log4j日志配置Bundles
这个Bundles的目的在于提供log4j.properties,详细做法可以参考本人的”spring osgi快速入门”
3 开发WEB应用
WEB应用的开发方式和普通的WEB基本上一样,只是加入一些OSGi的配置。
大致结构如下:
META-INF
MANIFEST.MF
WEB-INF
Classes
Lib
Web.xml
applicationContext.xml
1 MANIFEST.MF配置参考:
Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: Osgi_web_app Plug-in
Bundle-SymbolicName: osgi_web_app
Bundle-Version: 1.0.0
Bundle-Vendor: ccsoft
Import-Package: javax.servlet,
javax.servlet.http,
javax.servlet.resources;version="2.4.0",
org.ccsoft.service,
org.springframework.osgi.web.context.support;version="1.1.2",
org.springframework.web.context,
org.springframework.web.context.support
Bundle-ClassPath: WEB-INF/classes/,
.
Require-Bundle: org.springframework.bundle.osgi.core,
org.springframework.bundle.osgi.io,
org.springframework.bundle.spring.beans,
org.springframework.bundle.spring.context,
org.springframework.bundle.spring.core
2 为了在web应用中使用spring dm的IoC功能,web.xml中需要加入一些特定配置,类似于使用Spring时的配置,web.xml配置参考如下:
<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
version="2.4">
<display-name>Simple Osgi WebApp Bundle</display-name>
<description>Simple OSGi War</description>
<context-param>
<param-name>contextClass</param-name>
<param-value>org.springframework.osgi.web.context.support.OsgiBundleXmlWebApplicationContext</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<servlet>
<servlet-name>MyServlet</servlet-name>
<servlet-class>org.ccsoft.web.MyServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>MyServlet</servlet-name>
<url-pattern>/servlet</url-pattern>
</servlet-mapping>
</web-app>
至于applicationContext.xml则是标准的spring dm配置文件形式,只是没有放在我们所熟悉的位置(META-INF/spring)
配置示例:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:osgi="http://www.springframework.org/schema/osgi"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/osgi http://www.springframework.org/schema/osgi/spring-osgi.xsd">
<osgi:reference id="HelloServiceOsgi" interface="org.ccsoft.service.SpeakService"/>
</beans>
在你的WEB应用中可以使用如下代码来访问别的Bundle提供的服务:
WebApplicationContext ctx = WebApplicationContextUtils.getWebApplicationContext(req.getSession().getServletContext());
SpeakService ss=(SpeakService)ctx.getBean("HelloServiceOsgi");
与你使用Spring开发WEB应用的写法是完全一致的。
好了现在你可以利用spring dm开发你的web应用了。更多相关问题还会在后续文章中逐一讨论。
蔡超
软件架构师
Chao.cai@hp.com
Chaocai2001@yahoo.com.cn
致力于OSGi在中国的推广