对osgi有了一个初步的了解之后,准备写段代码跑跑,一试身手,
先下载了一份Bluedavy 的《OSGI实战》
里边有可以直接运行的代码,双击run.bat运行正常,暗爽!
开始练习《OSGI实战》中用户登录验证模块,一行一行敲代码,第一个变化就是工程之间相互引用不能在Build path里添加工程引用了,改成了在MANIFEST.MF当中添加Import-Package
在学习过程当中还是遇到了不少问题,记录下来,帮助遇到和我同样样问题的少走弯路。
我用的是eclipse3.4 jdk1.6
1.Import-Package时org.eclipse.equinox.servlet.api这个包死活找不到。
在eclipse3.4已经不存在了直接导入javax.servlet_2.4.0.v200806031604.jar就可以了
如果没有添加javax.servlet会出现 INSTALLED UserValidatorWebBundle_1.0.0
强行启动会抛出以下异常
org.osgi.framework.BundleException:
The bundle could not be resolved. Reason: Missing Constraint:
Require-Bundle: javax.servlet; bundle-version="2.4.0"
2.如果使用了Equinox OSGI Declarative Service需要下载 eclipse-equinox-SDK-3.4.2.zip
因为Declarative Service实现并没有包含在Eclipse的默认软件包中,需要单独从 Eclipse 的的网站上获得,下载包当中的plugins和features复制到eclipse当中重启
org.eclipse.equinox.ds_1.0.0.v20080427-0830.jar是运行时用到的bundle
org.eclipse.equinox.ds用到了org.eclipse.equinox.util_1.0.0.v20080414.jar
都要在config.ini当中添加并启动
3.一切看似启动正常了,log当中还是有以下异常
java.lang.IllegalStateException:
Unable to acquire application service. Ensure that the
org.eclipse.core.runtime bundle is resolved and started (see
config.ini).
还得启动 org.eclipse.osgi.util_3.1.300.v20080303.jar 这个bundle
4.如果http://localhost/demo/page/login.htm 这个页面不能访问可能org.eclipse.equinox.http_1.0.200.v20080421-2006.jar没有启动,如何htm能访问了http://localhost/demo/login 不能访问 可能org.eclipse.equinox.http.servlet_1.0.100.v20080427-0830.jar没有启动
总结一下用户登录验证模块要启动的bundle
id State Bundle
0 ACTIVE org.eclipse.osgi_3.4.2.R34x_v20080826-1230
1 ACTIVE ConfigFileValidatorBundle_1.0.0
2 ACTIVE DBValidatorBundle_1.0.0
4 ACTIVE UserValidatorBundle_1.0.0
5 ACTIVE LDAPValidatorBundle_1.0.0
9 ACTIVE UserValidatorWebBundle_1.0.0
10 ACTIVE org.eclipse.equinox.util_1.0.0.v20080414
11 ACTIVE org.eclipse.equinox.ds_1.0.0.v20080427-0830
12 ACTIVE javax.servlet_2.4.0.v200806031604
13 ACTIVE org.eclipse.osgi.services_3.1.200.v20071203
14 ACTIVE org.eclipse.equinox.http.servlet_1.0.100.v20080427-0830
15 ACTIVE org.eclipse.equinox.http_1.0.200.v20080421-2006
17 ACTIVE org.eclipse.osgi.util_3.1.300.v20080303
当缺少什么bundle时,自己去网上下就行,然后用导入Plug- ins and Fragments的方式将bundle导入,便可以引用了,所以别当成什么高深的东西,别忘了在运行时用"Add Required Bundles",它帮我们加入会用的的bundles,这个就帮我们很大的忙了.
在第一个例子(源码中的classic)中,用代码注册的方式来注册服务,即在每个实现服务接口的bundle里的Activator注册自己的服务到指定服务名下,如
- package org.riawork.demo.user.validator;
- /*
- * RIAWork.org
- *
- * OSGI Opendoc Demo
- */
- import org.osgi.framework.BundleActivator;
- import org.osgi.framework.BundleContext;
- import org.osgi.framework.ServiceRegistration;
- import org.riawork.demo.service.user.Validator;
- import org.riawork.demo.service.user.impl.ConfigFileValidatorImpl;
- /**
- * desc: ConfigFileBundle Activator,采用传统的方式完成服务的注册
- *
- * @author jerry
- */
- public class Activator implements BundleActivator {
- // --------------------------------------------Instance Variables
- private ServiceRegistration serviceReg=null;
- // --------------------------------------------Public Method
- /* (non-Javadoc)
- * @see org.osgi.framework.BundleActivator#start(org.osgi.framework.BundleContext)
- */
- //实现Validator的Bunble都会在Activator里将自己的新的实现注册到Validator.class.getName()名下,这样Validator.class.getName()为名的服务就有多个了
- public void start(BundleContext context) throws Exception {
- serviceReg=context.registerService(Validator.class.getName(), new ConfigFileValidatorImpl(), null);
- }
- /* (non-Javadoc)
- * @see org.osgi.framework.BundleActivator#stop(org.osgi.framework.BundleContext)
- */
- public void stop(BundleContext context) throws Exception {
- if(serviceReg!=null)
- serviceReg.unregister();
- }
- }
package org.riawork.demo.user.validator; /* * RIAWork.org * * OSGI Opendoc Demo */ import org.osgi.framework.BundleActivator; import org.osgi.framework.BundleContext; import org.osgi.framework.ServiceRegistration; import org.riawork.demo.service.user.Validator; import org.riawork.demo.service.user.impl.ConfigFileValidatorImpl; /** * desc: ConfigFileBundle Activator,采用传统的方式完成服务的注册 * * @author jerry */ public class Activator implements BundleActivator { // --------------------------------------------Instance Variables private ServiceRegistration serviceReg=null; // --------------------------------------------Public Method /* (non-Javadoc) * @see org.osgi.framework.BundleActivator#start(org.osgi.framework.BundleContext) */ //实现Validator的Bunble都会在Activator里将自己的新的实现注册到Validator.class.getName()名下,这样Validator.class.getName()为名的服务就有多个了 public void start(BundleContext context) throws Exception { serviceReg=context.registerService(Validator.class.getName(), new ConfigFileValidatorImpl(), null); } /* (non-Javadoc) * @see org.osgi.framework.BundleActivator#stop(org.osgi.framework.BundleContext) */ public void stop(BundleContext context) throws Exception { if(serviceReg!=null) serviceReg.unregister(); } }
在第二个例子(源码中的ds),采用的是在配置文件里声明的方式来发布一个bundle里的服务的,即在 ConfigFileValidatorBundle,DBValidatorBundle,LDAPValidatorBundle这三个实现 UserValidatorBundle接口的bundle里没有Activator来注册它们的实现服务,而是在MANIFEST.MF配置文件里加入 Service-Component: OSGI-INF/component.xml来发布声明在项目目录下的OSGI-INF/component.xml配置文件的服务。
打包时,按着文档来做是不行的,打包的时候,org.eclipse.osgi的jar包和run.bat是在一个目录里,而在它们目录下再建 configuration目录(存放config.ini文件)和bundles目录(存放自己打包出来的bundle和它们运行依赖的 bundle),还有一点在注意的是拷贝文档里的config.ini内容到config.ini文件是不能运行的,可以是有中文字符在里面。
我这里能运行的如下:
- osgi.noShutdown=true
- # 当前系统下运行的 Bundle,可以在此指定 Bundle 的启动顺序,在后续的
- # StartLevel Service章节中会详细的介绍
- #避免Unable to acquire application service. Ensure that the org.eclipse.core.runtime错误
- eclipse.ignoreApp=true
- #osgi.bundles=reference\:file\:bundles/ConfigFileValidatorBundle_1.0.0.jar@start,reference\:file\:bundles/DBValidatorBundle_1.0.0.jar@start,reference\:file\:bundles/LDAPValidatorBundle_1.0.0.jar@start,reference\:file\:bundles/org.eclipse.equinox.http_1.0.301.R35x_v20090728.jar@start,reference\:file\:bundles/javax.servlet_2.5.0.v200806031605.jar@start,reference\:file\:bundles/org.eclipse.osgi.services_3.2.0.v20090520-1800.jar@start,reference\:file\:bundles/UserValidatorBundle_1.0.0.jar@start, reference\:file\:bundles/UserValidatorWebBundle_1.0.0.jar@start
- osgi.bundles=plugins/ConfigFileValidatorBundle_1.0.0.jar@start,\
- plugins/DBValidatorBundle_1.0.0.jar@start,\
- plugins/LDAPValidatorBundle_1.0.0.jar@start,\
- plugins/org.eclipse.equinox.http_1.0.301.R35x_v20090728.jar@start,\
- plugins/javax.servlet_2.5.0.v200806031605.jar@start,\
- plugins/org.eclipse.osgi.services_3.2.0.v20090520-1800.jar@start,\
- plugins/UserValidatorBundle_1.0.0.jar@start,\
- plugins/UserValidatorWebBundle_1.0.0.jar@start,\
- plugins/org.eclipse.equinox.ds_1.1.1.R35x_v20090806.jar@start,\
- plugins/org.eclipse.equinox.util_1.0.100.v20090520-1800.jar@start
- osgi.bundles.defaultStartLevel=4
osgi.noShutdown=true # 当前系统下运行的 Bundle,可以在此指定 Bundle 的启动顺序,在后续的 # StartLevel Service章节中会详细的介绍 #避免Unable to acquire application service. Ensure that the org.eclipse.core.runtime错误 eclipse.ignoreApp=true #osgi.bundles=reference\:file\:bundles/ConfigFileValidatorBundle_1.0.0.jar@start,reference\:file\:bundles/DBValidatorBundle_1.0.0.jar@start,reference\:file\:bundles/LDAPValidatorBundle_1.0.0.jar@start,reference\:file\:bundles/org.eclipse.equinox.http_1.0.301.R35x_v20090728.jar@start,reference\:file\:bundles/javax.servlet_2.5.0.v200806031605.jar@start,reference\:file\:bundles/org.eclipse.osgi.services_3.2.0.v20090520-1800.jar@start,reference\:file\:bundles/UserValidatorBundle_1.0.0.jar@start, reference\:file\:bundles/UserValidatorWebBundle_1.0.0.jar@start osgi.bundles=plugins/ConfigFileValidatorBundle_1.0.0.jar@start,\ plugins/DBValidatorBundle_1.0.0.jar@start,\ plugins/LDAPValidatorBundle_1.0.0.jar@start,\ plugins/org.eclipse.equinox.http_1.0.301.R35x_v20090728.jar@start,\ plugins/javax.servlet_2.5.0.v200806031605.jar@start,\ plugins/org.eclipse.osgi.services_3.2.0.v20090520-1800.jar@start,\ plugins/UserValidatorBundle_1.0.0.jar@start,\ plugins/UserValidatorWebBundle_1.0.0.jar@start,\ plugins/org.eclipse.equinox.ds_1.1.1.R35x_v20090806.jar@start,\ plugins/org.eclipse.equinox.util_1.0.100.v20090520-1800.jar@start osgi.bundles.defaultStartLevel=4
这里不要忘记加入ds的bundle不然用Service-Component: OSGI-INF/component.xml配置就不起作用了,发布不了服务的,因为是由ds的bundle来扫描发现相应的服务,并加于管理的。