OSGI:构建Spring DM开发环境

spring dm又称spring动态模型，是spring对于osgi的实现，它仍然以Equinox为集成，但提供了大量与sping pojo相关的bundle，极大的方便了与现有基于spring开发的应用的整合。此次依旧使用SpringSource Tool Suite进行开发。

一、下载spring dm

开发中使用了spring-osgi-1.2.1-with-dependencies.zip，该压缩包中包含了spring osgi所依赖的类库。解压后dist目录是spring osgi的bundle，lib是可能依赖的类库，也以bundle的形式存在。

二、引用spring bundle

在STS中import/Plug-in Development/Plug-ins and Frgments，选择解压后的dist和list，将com.springsource.org.aopalliance,

org.springframework.aop,

org.springframework.beans,

org.springframework.core,

org.springframework.context,

org.springframework.osgi.core,

org.springframework.osgi.extender,

org.springframework.osgi.io

这些bundle导入进来。

三、建立helloworld

1. 建立Plug-in Development/Plug-in Project工程helloworld，不生成Activator；

2. 在META-INF目录中建立spring文件夹，使用spring dm会自动加载此文件夹中的.xml文件；

3. 分别通过spring/Spring Bean Configuration File建立helloworld.xml和helloworld-osgi.xml，并在helloworld-osgi.xml文件中添加osgi命名空间的支持；

4. 建立HelloWorld接口和HelloWorldImpl作为实现类：

package org.jack; public interface HelloWorld { public String sayHello(String name); }

package org.jack.impl; import org.jack.HelloWorld; public class HelloWorldImpl implements HelloWorld { public String sayHello(String name) { return "hello, " + name; } }

5. 编辑helloworld.xml，用于配置spring的pojo模型，根据spring的建议-osgi表示osgi服务等相关的配置，而没有-osgi的文件用于配置spring的pojo逻辑，但这只是建议，可以根据自己的喜好明明，因为spring dm会默认自动加载此文件夹下的所有xml文件：

<?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.xsd"> <bean id="helloWorld" class="org.jack.impl.HelloWorldImpl" /> </beans>

通过osgi:service将bean发布为服务：

<?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/osgi http://www.springframework.org/schema/osgi/spring-osgi-1.2.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <osgi:service id="helloWorldService" interface="org.jack.HelloWorld" ref="helloWorld" /> </beans>

注意osgi的名称空间不要使用http://www.springframework.org/schema/osgi/spring-osgi-2.0-m1.xsd，因为STS默认使用了次空间，但目前使用会报错（在ubuntu中可以正常使用），因此需要修改为：http://www.springframework.org/schema/osgi/spring-osgi-1.2.xsd，如果不更改所报异常如下：

严重: Application context refresh failed (OsgiBundleXmlApplicationContext(bundle=jack.helloworld, config=osgibundle:/META-INF/spring/*.xml)) org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'helloWorldService': Error setting property values; nested exception is org.springframework.beans.NotWritablePropertyException: Invalid property 'cacheTarget' of bean class [org.springframework.osgi.service.exporter.support.OsgiServiceFactoryBean]: Bean property 'cacheTarget' is not writable or has an invalid setter method. Does the parameter type of the setter match the return type of the getter? at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1279) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1010) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:472) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:409) at java.security.AccessController.doPrivileged(Native Method) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:380) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:264) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:261) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:185) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:164) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:423) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:728) at org.springframework.osgi.context.support.AbstractDelegatedExecutionApplicationContext.access$1600(AbstractDelegatedExecutionApplicationContext.java:69) at org.springframework.osgi.context.support.AbstractDelegatedExecutionApplicationContext$4.run(AbstractDelegatedExecutionApplicationContext.java:355) at org.springframework.osgi.util.internal.PrivilegedUtils.executeWithCustomTCCL(PrivilegedUtils.java:85) at org.springframework.osgi.context.support.AbstractDelegatedExecutionApplicationContext.completeRefresh(AbstractDelegatedExecutionApplicationContext.java:320) at org.springframework.osgi.extender.internal.dependencies.startup.DependencyWaiterApplicationContextExecutor$CompleteRefreshTask.run(DependencyWaiterApplicationContextExecutor.java:132) at java.lang.Thread.run(Thread.java:619) Caused by: org.springframework.beans.NotWritablePropertyException: Invalid property 'cacheTarget' of bean class [org.springframework.osgi.service.exporter.support.OsgiServiceFactoryBean]: Bean property 'cacheTarget' is not writable or has an invalid setter method. Does the parameter type of the setter match the return type of the getter? at org.springframework.beans.BeanWrapperImpl.setPropertyValue(BeanWrapperImpl.java:801) at org.springframework.beans.BeanWrapperImpl.setPropertyValue(BeanWrapperImpl.java:651) at org.springframework.beans.AbstractPropertyAccessor.setPropertyValues(AbstractPropertyAccessor.java:78) at org.springframework.beans.AbstractPropertyAccessor.setPropertyValues(AbstractPropertyAccessor.java:59) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1276) ... 18 more Exception in thread "SpringOsgiExtenderThread-4" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'helloWorldService': Error setting property values; nested exception is org.springframework.beans.NotWritablePropertyException: Invalid property 'cacheTarget' of bean class [org.springframework.osgi.service.exporter.support.OsgiServiceFactoryBean]: Bean property 'cacheTarget' is not writable or has an invalid setter method. Does the parameter type of the setter match the return type of the getter? at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1279) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1010) at

四、运行

要想能正常运行还有添加org.eclipse.osgi_3.5.2.R35x_v20100126和org.apache.commons.logging_1.0.4.v200904062259两个bundle，启动后发现helloworld已经处于ACTIVE状态了，此时stop和start都没有问题，说明运行成功。