我的 OSGi 捆绑包多次意外启动和停止

Question

我实现了一个 OSGi 捆绑包，它根据其 service.xml 注入一些其他服务。事实证明，如果激活策略设置为惰性，我的​​包确实会被激活。其他服务注入正确。

主要问题是，捆绑包会根据注入的其他服务的数量多次启动和停止。如果我将注入服务的数量减少到只有一个，则捆绑只启动一次。通过注入 5 个其他服务，它启动和停止 3 次，其中最后一次启动没有停止，因此启动 TCP 服务器的服务可以正常工作。尽管它工作正常，但这种行为很奇怪并且完全出乎意料。

我不知道如何避免这种情况，因为我不知道这是怎么发生的。

日志：

[Component Resolve Thread] INFO A.B.SimServiceComponent - Setting a 23347814 for instance 28219381
[Component Resolve Thread] INFO A.B.SimServiceComponent - Setting b 260627 for instance 28219381
[Component Resolve Thread] INFO A.B.SimServiceComponent - Setting c 22735430 for instance 28219381
[Component Resolve Thread] INFO A.B.SimServiceComponent - Setting d 4256633 for instance 28219381
[Component Resolve Thread] INFO A.B.SimServiceComponent - Setting e service 27446331 for instance 28219381
[Component Resolve Thread] INFO A.B.SimServiceComponent - Starting SimService now . . . 28219381
[Component Resolve Thread] INFO A.OTHER - starting component
[Component Resolve Thread] INFO A.OTHER - starting component
[Component Resolve Thread] INFO A.OTHER - starting component
[Component Resolve Thread] INFO A.OTHER - starting component
[Component Resolve Thread] INFO A.OTHER - starting component
[Component Resolve Thread] INFO A.B.SimServiceComponent - Stopping SimService now . . . 28219381
[Component Resolve Thread] INFO A.B.SimServiceComponent - SimService stopped.
[Component Resolve Thread] INFO A.B.SimServiceComponent - Setting a 23347814 for instance 606383
[Component Resolve Thread] INFO A.B.SimServiceComponent - Setting b 260627 for instance 606383
[Component Resolve Thread] INFO A.B.SimServiceComponent - Setting c 28883317 for instance 606383
[Component Resolve Thread] INFO A.B.SimServiceComponent - Setting d 4256633 for instance 606383
[Component Resolve Thread] INFO A.B.SimServiceComponent - Setting e service 27446331 for instance 606383
[Component Resolve Thread] INFO A.B.SimServiceComponent - Starting SimService now . . . 606383
[Component Resolve Thread] INFO A.B.SimServiceComponent - Stopping SimService now . . . 606383
[Component Resolve Thread] INFO A.B.SimServiceComponent - SimService stopped.
[Component Resolve Thread] INFO A.B.SimServiceComponent - Setting a 23347814 for instance 33352835
[Component Resolve Thread] INFO A.B.SimServiceComponent - Setting b 260627 for instance 33352835
[Component Resolve Thread] INFO A.B.SimServiceComponent - Setting c 31287346 for instance 33352835
[Component Resolve Thread] INFO A.B.SimServiceComponent - Setting d 4256633 for instance 33352835
[Component Resolve Thread] INFO A.B.SimServiceComponent - Setting e service 27446331 for instance 33352835
[Component Resolve Thread] INFO A.B.SimServiceComponent - Starting SimService now . . . 33352835 

service.xml：

<?xml version="1.0" encoding="UTF-8"?>
<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.1.0" activate="activate" deactivate="deactivate" immediate="true" name="SimService">
   <implementation class="SimServiceComponent"></implementation>
   <service>
        <provide interface="ServiceComponent"></provide>
   </service>
   <reference bind="setA" cardinality="1..1" interface="A" name="A" policy="static"/>
   <reference bind="setB" cardinality="1..1" interface="B" name="B" policy="static"/>
   <reference bind="setC" cardinality="1..1" interface="C" name="C" policy="static"/>
   <reference bind="setD" cardinality="1..1" interface="D" name="D" policy="static"/>
   <reference bind="setE" cardinality="1..1" interface="E" name="E" policy="static"/>
</scr:component>

服务设置器的激活方法和示例：

public void setA(final A a) {
        LOG.info("Setting a {} for instance {} ", a.hashCode(), hashCode());
        _a = a;
 }

 public void setB(final B b) {
        LOG.info("Setting b {} for instance {} ", b.hashCode(), hashCode());
        _b = b;
 }


 public void activate(BundleContext bundleContext) throws Exception {
        LOG.info("Starting SimService now . . . {}", hashCode());       
 }

感谢您的帮助:-)

编辑：

这个包内的服务不被任何其他包/服务消费，所以没有循环依赖。

Answer 1

在您的日志消息中添加哈希码身份是明智之举！说明虽然服务A、B、D和E是不变的，但服务C的身份每次都在变化。

这意味着原始的C 服务由于某种原因已从服务注册表中注销。因为您的SimServiceComponent 组件具有对服务C 的强制1..1 引用，所以当C 消失时，它会被强制停用。然后服务C 回来（更准确地说，注册了一个新的C 服务），它允许您的组件被重新激活。

因此，您需要了解C 服务为何循环。