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OSGi开发之Event:事件处理[原]

作者:coolflyr_reg 日期:2008-07-25 16:39:16

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首先配置OSGi Framework的运行环境，我的Eclipse是3.3的，运行环境需要以下的Bundle：

? org.eclipse.osgi
? org.eclipse.equinox.ds
? org.eclipse.equinox.registry
? org.eclipse.equinox.common
? org.eclipse.equinox.log
? org.eclipse.osgi.services
? org.eclipse.equinox.event
? org.eclipse.osgi.util


操作步骤：点击菜单Run->Open Run Dialog…，在左侧的列表中，找到OSGi Framework，右键单击，New，修改Name为EventDemo，并在Bundles选项卡中，选中以上列举的Bundle，然后点击Apply，点Run。

在Console中输入ss来查看我们的环境是否成功运行： 
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osgi> ss
 
Framework is launched.
 
id	State       Bundle
0	ACTIVE      org.eclipse.osgi_3.3.1.R33x_v20070828
1	ACTIVE      org.eclipse.equinox.common_3.3.0.v20070426
2	ACTIVE      org.eclipse.equinox.log_1.0.100.v20070226
3	ACTIVE      org.eclipse.equinox.ds_1.0.0.qualifier
4	ACTIVE      org.eclipse.equinox.registry_3.3.1.R33x_v20070802
5	ACTIVE      org.eclipse.osgi.services_3.1.200.v20070605
6	ACTIVE      org.eclipse.equinox.event_1.0.100.v20070516
7	ACTIVE      org.eclipse.osgi.util_3.1.200.v20070605
 
osgi>


OK，这样我们的Spring-OSGi的环境就启动好了，现在先关闭它。我们来建立一个Plug-in Project，命名为：EventPublisher。

首先新建一个类：com.demo.eventpublisher.Log，代码如下： 
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package com.demo.eventpublisher;
 
import org.osgi.framework.BundleContext;
import org.osgi.service.log.LogService;
import org.osgi.util.tracker.ServiceTracker;
 
/**
 * Utility class with static methods for logging to LogService, if available 
 * 
 * @version $Revision: 1.1 $
 */
public class Log {
 
	static private ServiceTracker logTracker;
 
	private Log() {
	}
 
	public static void init(BundleContext bc) {
		logTracker = new ServiceTracker(bc, LogService.class.getName(), null);
		logTracker.open();
	}
 
	static void dispose() {
		if (logTracker != null) {
			logTracker.close();
		}
		logTracker = null;
	}
 
	public static void log(int level, String message) {
		log(level, message, null);、
	}
 
	public static void log(int level, String message, Throwable e) {
		LogService logService = (LogService) logTracker.getService();
		if (logService != null) {
			logService.log(level, message, e);
		}
	}
 
	public static void info(String message)
	{
		info(message, null);
	}
 
	public static void info(String message, Throwable e)
	{
		log(LogService.LOG_INFO, message, e);
	}
}

接下来创建一个循环发布事件的线程：com.demo.eventpublisher.TimerEvent，代码如下： 
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package com.demo.eventpublisher;
 
import java.util.Calendar;
import java.util.Hashtable;
 
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.service.event.Event;
import org.osgi.service.event.EventAdmin;
import org.osgi.util.tracker.ServiceTracker;
 
public class TimerEvent extends Thread implements BundleActivator {
    Hashtable time = new Hashtable();
    ServiceTracker tracker;
 
    public TimerEvent() {
        super("TimerEvent");
    }
 
    public void start(BundleContext context) {
        Log.init(context);
        tracker = new ServiceTracker(context, EventAdmin.class.getName(), null);
        tracker.open();
        start();
    }
 
    public void stop(BundleContext context) {
        interrupt();
        tracker.close();
        Log.dispose();
    }
 
    public void run() {
        while (!Thread.interrupted())
            try {
                Log.info("Rasie Event");
                Calendar c = Calendar.getInstance();
                set(c, Calendar.MINUTE, "minutes");
                set(c, Calendar.HOUR, "hours");
                set(c, Calendar.DAY_OF_MONTH, "day");
                set(c, Calendar.MONTH, "month");
                set(c, Calendar.YEAR, "year");
                EventAdmin ea = (EventAdmin) tracker.getService();
                if (ea != null)
                    ea.sendEvent(new Event("com/demo/timer", time));
                Thread.sleep(60000 - c.get(Calendar.SECOND) * 1000);
            }
            catch (InterruptedException e) {
                // 忽略
            }
    }
 
    void set(Calendar c, int field, String key) {
        time.put(key, new Integer(c.get(field)));
    }
}


在Plug-in ManiFest Editor中打开META-INF/MANIFEST.MF，如果安装了PDE，将会默认使用Plug-in ManiFest Editor打开。将Activator设置为com.demo.eventpublisher.TimerEvent，此时MANIFEST.MF文件中的内容如下： 
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Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: EventPublisher Plug-in
Bundle-SymbolicName: EventPublisher
Bundle-Version: 1.0.0
Bundle-Activator: com.demo.eventpublisher.TimerEvent
Import-Package: org.osgi.framework;version="1.3.0",
 org.osgi.service.event;version="1.1.0",
 org.osgi.service.log;version="1.3.0",
 org.osgi.util.tracker;version="1.3.2"
 

注意：手工写MANIFEST.MF文件时，最后一行一定要有一个回车。

接下来我们再来建立一个Plug-in Project，命名为EventHander。

我们建立一个类，名为：com.demo.eventhandler.CustomEventHandler，代码如下 
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package com.demo.eventhandler;
 
import java.util.Dictionary;
import java.util.Hashtable;
 
import org.osgi.framework.BundleContext;
import org.osgi.service.event.Event;
import org.osgi.service.event.EventConstants;
import org.osgi.service.event.EventHandler;
 
import com.demo.internal.Log;
 
public class CustomEventHandler implements EventHandler
{
    public final static String [] topics = new String[] { 
//        "org/osgi/service/log/LogEntry/LOG_INFO", 
//        "org/osgi/service/log/LogEntry/LOG_WARNING",
//        "org/osgi/framework/ServiceEvent/REGISTERED",
//        "org/osgi/framework/ServiceEvent/MODIFIED",
//        "org/osgi/framework/ServiceEvent/UNREGISTERING",
//        "org/osgi/framework/FrameworkEvent/STARTED",
//        "org/osgi/service/log/LogEntry/LOG_ERROR",
        "com/demo/timer"}; 
    
    public void registry(BundleContext context)
    {
        Dictionary d = new Hashtable(); 
        d.put(EventConstants.EVENT_TOPIC, topics ); 
 
        context.registerService( EventHandler.class.getName(), this, d ); 
    }
    public void handleEvent(Event event)
    {
        if ("com/acme/timer".equals(event.getTopic()))
        {
            Log.info("Received event, EventTopic " + event.getTopic() + " " + event.getProperty("year") + "-" + event.getProperty("month") + "-" + event.getProperty("day"));
        }
        else
        {
            Log.info("Received event, EventTopic " + event.getTopic());
        }  
    }
}


我们再建立一个Activator，名为：com.demo.eventhandler.internal.Activator，代码如下 
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package com.demo.internal;
 
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
 
import com.demo.eventhandler.CustomEventHandler;
 
 
public class Activator implements BundleActivator
{
    public void start(BundleContext context) throws Exception
    {
        Log.init(context);
        CustomEventHandler eventhandler = new CustomEventHandler();
        eventhandler.registry(context);
    }
 
    public void stop(BundleContext context) throws Exception
    {
        Log.dispose();
    }
}

OK，我们将新建立的这两个Bundle加入到运行环境中，Run。
在Console中等待大约60秒后，输入log后可以在最后找到如下日志信息：
引用原文:

>Info [1] Rasie Event initial@reference:file:../../../../../../../../Documents/workspace/EventPublisher/
>Info [7] Received event, EventTopic com/demo/timer initial@reference:file:../../../../../../../../Documents/workspace/ConsumerServiceDemo/

瞧，我们已经收到打印出来的事件接收信息了 Received event, EventTopic com/demo/timer

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文章来自: 本站原创
标签: event OSGi EventHandler 
评论: 4 | 查看次数: 3867
  • 共有 4 条评论
xiaoxue00 [2010-06-07 10:47:13]
Voulez-vous acheter wow gold offre GameSavor, il
offre GameSavor powerleveling depuis de nombreuses années
économiques power level dans GameSavor
beeflee [2009-05-08 15:18:06]
coolflyr_reg [2008-08-22 11:25:57]
没错，不过既然要作OSGi，那么PDE是前提！

不过我是从更新Eclipse的更新里面更新下来得PDE，如果缺少包的话，完全可以去Eclipse的CVS上Checkout一个出来，或者使用maven来使其自动下载依赖的包，但是依赖于apache。
游客 [2008-08-14 16:20:29]
eclipse要装rcp版本的，要不然缺少osgi包
  • 共有 4 条评论
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