Question

当我在osgi中使用我的Bundle时，我需要ServiceReference和Service Object。但是，当我按照下面的代码显示时，我的bundle无法再找到bind方法。我做错了什么？

public class AServiceImpl implements AService{

    TestService t;
    JournalService journalService;
    BundleContext context;
    ServiceReference testServiceRef;

    public void bindTestService(TestService testService, ServiceReference sv) {
        t = testService;
            testServiceRef = sv;
        //this.testServiceRef = testServiceRef;
        test.api.TestStaticVariable.getUniqueInstance().add("TEST A");
        System.out.println(test.api.TestStaticVariable.getUniqueInstance().toString());
    }

    public void unbindTestService(TestService testService){
        System.out.println("");
        if(t.equals(testService)){
            t = null;
        }
    }

    public void bindJournalService(JournalService journalService){
        this.journalService = journalService;  
    }

    public void unbindJournalService(JournalService journalService){
        if(this.journalService.equals(journalService)){
            this.journalService = null;
        }
    }   
}

Answer 1

见https://osgi.org/download/r4v43/osgi.cmpn-4.3.0.pdf的OSGi纲要4.3第112.3.2节。

所以只需使用ServiceReference并通过组件上下文获取对象，如112.3.2中所述。

Answer 2

我找到了解决问题的正确方法：

我只使用从activate方法中检索的BundleContext。在那里，我使用的方法：

testServiceRef = context.getServiceReference(TestService.class);

从bind方法中检索TestService。

Answer 3

您可以简单地使用FrameworkUtil#getBundle获取任何类的捆绑包，从中可以获取BundleContext。然后从BundleContext中获得ServiceReference，最终可以从BundleContext API中get the service instance。

    import org.apache.sling.api.resource.ResourceResolverFactory;
    import org.osgi.framework.Bundle;
    import org.osgi.framework.BundleContext;
    import org.osgi.framework.FrameworkUtil;
    import org.osgi.framework.ServiceReference;

    public class GetServiceDemo {

        public static ResourceResolverFactory getResourceResolverFactory(){
            Bundle bundle = FrameworkUtil.getBundle(ResourceResolverFactory.class);
            BundleContext bundleContext = bundle.getBundleContext();
            ServiceReference<ResourceResolverFactory> resourceResolverFactoryServiceReference = bundleContext.getServiceReference(ResourceResolverFactory.class);
            ResourceResolverFactory resourceResolverFactory = bundleContext.getService(resourceResolverFactoryServiceReference);
            return resourceResolverFactory;
        }
    }

ResourceResolverFactory是已注册的服务。

使用声明性服务时，如何同时获取Service Object和ServiceReference

3 个答案: