通过ServiceTracker能够对查找的Service进行扩展
以下的demo引入装饰器模式对Service进行日志的扩展
demo:
Provider
student-manage/Activator.java
package com.demo.service;import java.util.Dictionary;import java.util.HashMap;import java.util.Hashtable;import java.util.Map;import org.osgi.framework.BundleActivator;import org.osgi.framework.BundleContext;import com.demo.service.impl.StudentManage;public class Activator implements BundleActivator { public void start(BundleContext context) throws Exception { System.out.println("register service start..."); Dictionaryprop=new Hashtable (); prop.put("action", "student_action"); context.registerService(IStudentManage.class.getName(), new StudentManage(), prop); System.out.println("register service end..."); } public void stop(BundleContext context) throws Exception { }}
Consumer
student-action/Activator.java
package com.demo.action;import org.osgi.framework.BundleActivator;import org.osgi.framework.BundleContext;import com.demo.action.log.LogStudentManager;import com.demo.action.tracker.StudentManagerTracker;import com.demo.service.IStudentManage;public class Activator implements BundleActivator{ StudentManagerTracker managerTracker ; public void start(BundleContext context) throws Exception { System.out.println("action start begin..."); managerTracker=new StudentManagerTracker(context); //开启 managerTracker.open(); //获取服务 IStudentManage service=(IStudentManage)managerTracker.getService(); service.add(); System.out.println("action start end..."); } public void stop(BundleContext context) throws Exception { //关闭 managerTracker.close(); }}
student-action/StudentManagerTracker.java
package com.demo.action.tracker;import org.omg.PortableInterceptor.INACTIVE;import org.osgi.framework.BundleContext;import org.osgi.framework.Filter;import org.osgi.framework.ServiceReference;import org.osgi.util.tracker.ServiceTracker;import org.osgi.util.tracker.ServiceTrackerCustomizer;import com.demo.action.log.LogStudentManager;import com.demo.service.IStudentManage;public class StudentManagerTracker extends ServiceTracker { public StudentManagerTracker(BundleContext context) { super(context, IStudentManage.class.getName(), null); } @Override public Object addingService(ServiceReference reference) { IStudentManage manage=new LogStudentManager(context, reference); return manage; } @Override public void open() { super.open(); } }
student-action/LogStudentManager.java
package com.demo.action.log;import org.osgi.framework.BundleContext;import org.osgi.framework.ServiceReference;import com.demo.service.IStudentManage;public class LogStudentManager implements IStudentManage { IStudentManage studentManage; BundleContext context; ServiceReference reference; public LogStudentManager(BundleContext context, ServiceReference reference) { this.context = context; this.reference = reference; } public void add() { studentManage=(IStudentManage) context.getService(reference); System.out.println("log start..."); studentManage.add(); System.out.println("log end..."); }}结果: