SpringDM笔记6-Fragment及配置Log4j Fragment Bundle
未配置日志配置文件前，系统会抛出下面异常：
log4j:WARN No appenders could be found forlogger(org.springframework.osgi.extender.internal
.boot.ChainActivator). log4j:WARN Please initialize the log4j system properly.
1. Using the fragement configuration pattern
一个Fragment是一个incomplate的Bundle,没有指定主Bundle是不能单独存在的，他不许附属于一个Host
Bundle. 它可以包含配置信息，classs文件，资源文件，但它不能有自己的Activator类或类加载器。
The host bundle can’t itself be a fragment and must be a full-fledged bundle, even if it relies on its
fragment to add classes or resources. A fragment can serve many purposes, such as completing
its host bundle with specific classes or providing configuration through resources (property or XML
files).
2. SpringDM's extender Export出来的通过Fragment可被修改的值：
(1)spring-osgi-extender.jar Bean Values Exposed for Fragments：见附件spring-osgi-extender.jar
Bean Values Exposed for Fragments.jpg;
(2)spring-osgi-web-extender.jar Bean Values Exposed for Fragments:见附件spring-osgi-web-
extender.jar Bean Values Exposed for Fragments.jpg.
3. 实现Log4jFragment
(1) Fragement目录结构：
log4j-config/
META-INF/
MANIFEST.MF
log4j.properties
（2）MAINFESt.MF文件：
Manifest-Version: 1.0
Fragment-Host: com.springsource.org.apache.log4j
Bundle-Version: 1.0.0
Bundle-Name: Log4J Configuration
Created-By: 1.6.0_13 (Sun Microsystems Inc.)
Bundle-ManifestVersion: 2
Bundle-SymbolicName: com.springsource.org.apache.log4j.config
(3) log4j.properties:
log4j.rootLogger=INFO, FILE
log4j.appender.FILE=org.apache.log4j.FileAppender
log4j.appender.FILE.File=SpringDM.log
log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.FILE.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n%M
(4) 打包生成JAR：
在log4j-config上一级目录中执行：
jar cvfm log4j-config.jar log4j-config/META-INF/MANIFEST.MF -C log4j-config 。
生成log4j-config.jar。
4. 安装该Fragement至OSGi 容器
在config.ini文件组中增加：bundles/log/log4j-config.jar
启动容器后，该Bundle的状态为：RESOLVED。
5. 实现启用SpringDM注解功能的Fragment
(1)目录组织结构
SpringDM-Annotation-config/
META-INF/
spring/
extender/
annotation-activator.xml
MANIFEST.MF
(2) MANIFEST.MF文件
Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Fragment-Host: org.springframework.bundle.osgi.extender
Bundle-SymbolicName: com.apress.springosgi.ch4.fragment
Bundle-Name: HelloWorld Spring-OSGi Fragment
Bundle-Description: Spring-DM Fragment for activating OSGi annotation scanning
(3) annotation-activator.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="extenderProperties">
<property name="process.annotations" value="true"/>
</bean>
</beans>