Question

我正在尝试向消费者发送事件。我收到NullPointerException

这是我的活动代码

public class Activator implements BundleActivator {

    EventAdmin eventAdmin;
    @Override
    public void start(BundleContext bundleContext) throws Exception {
        System.out.println("started");
        Dictionary<String, String> properties = new Hashtable<>();
        properties.put("test", "blah");
        Event event = new Event("test/sent", properties);
        System.out.println("sending");
        eventAdmin.sendEvent(event);
    }

    @Override
    public void stop(BundleContext bundleContext) throws Exception {
        System.out.println("stopped ");
    }
}

这是日志

org.osgi.framework.BundleException：中的异常套件h的com.aml.project.Activator.start（）。在 org.eclipse.osgi.internal.framework.BundleContextImpl.startActivator（BundleContextImpl.java:863）在 org.eclipse.osgi.internal.framework.BundleContextImpl.start（BundleContextImpl.java:791）在 org.eclipse.osgi.internal.framework.EquinoxBundle.startWorker0（EquinoxBundle.java:1013）在 org.eclipse.osgi.internal.framework.EquinoxBundle $ EquinoxModule.startWorker（EquinoxBundle.java:365）在org.eclipse.osgi.container.Module.doStart（Module.java:598）处 org.eclipse.osgi.container.Module.start（Module.java:462）在 org.eclipse.osgi.internal.framework.EquinoxBundle.start（EquinoxBundle.java:439）在org.apache.felix.gogo.command.Basic.start（Basic.java:739）处 java.base / jdk.internal.reflect.NativeMethodAccessorImpl.invoke0（本机方法） java.base / jdk.internal.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:62）在 java.base / jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）在java.base / java.lang.reflect.Method.invoke（Method.java:567）在 org.apache.felix.gogo.runtime.Reflective.invoke（Reflective.java:139）在 org.apache.felix.gogo.runtime.CommandProxy.execute（CommandProxy.java:91）在org.apache.felix.gogo.runtime.Closure.executeCmd（Closure.java:599）在 org.apache.felix.gogo.runtime.Closure.executeStatement（Closure.java:526）在org.apache.felix.gogo.runtime.Closure.execute（Closure.java:415）在org.apache.felix.gogo.runtime.Pipe.doCall（Pipe.java:416）处 org.apache.felix.gogo.runtime.Pipe.call（Pipe.java:229）在 org.apache.felix.gogo.runtime.Pipe.call（Pipe.java:59）在 java.base / java.util.concurrent.FutureTask.run（FutureTask.java:264）在 java.base / java.util.concurrent.ThreadPoolExecutor.runWorker（ThreadPoolExecutor.java:1128）在 java.base / java.util.concurrent.ThreadPoolExecutor $ Worker.run（ThreadPoolExecutor.java:628）在java.base / java.lang.Thread.run（Thread.java:835）造成原因： java.lang.NullPointerException在 com.aml.project.Activator.start（Activator.java:21）位于 org.eclipse.osgi.internal.framework.BundleContextImpl $ 3.run（BundleContextImpl.java:842）在 org.eclipse.osgi.internal.framework.BundleContextImpl $ 3.run（BundleContextImpl.java:1）在 java.base / java.security.AccessController.doPrivileged（AccessController.java:552）在 org.eclipse.osgi.internal.framework.BundleContextImpl.startActivator（BundleContextImpl.java:834） ... 23更多java.lang.NullPointerException

Answer 1

您使用从未设置的eventAdmin字段。这样就得到了NullPointerException。我建议改用声明式服务，并使用@Reference注入EventAdmin。

有关所有详细信息，请参见Vogella的OSGi Event Admin – Publish & Subscribe。

OSGI EventAdmin无法发送事件-生产者上出现空点异常

1 个答案: