使用XML解析器实现作为OSGi服务-UsingXMLparserimplementationasOSGiservice

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Generally it is not a good idea to use JAXP in OSGi (because of the classloading mechanism primarily) and a much better idea to get the factory like a service.

一般来说，在OSGi中使用JAXP并不是一个好主意(因为主要是类加载机制)，而且更好的想法是让工厂像一个服务一样。

If you are using equinox, the SaxParserFactory (using the JRE/JDK one you are running on) is actually provided by the System Bundle, which means you don't need extra bundles:

如果您正在使用equinox, SaxParserFactory(使用您正在运行的JRE/JDK)实际上是由System Bundle提供的，这意味着您不需要额外的Bundle:

{javax.xml.parsers.SAXParserFactory}={service.id=6} Registered by bundle: System Bundle [0]

{ javax.xml.parsers.SAXParserFactory } = {服务。id=6}由bundle注册:System bundle [0

If you want to write code that deals with the lifecycle layer of the OSGi platform, I would suggest to track the reference, rather than looking it up directly. There are many approaches for this; I have written about one I call ServiceMediator here.

如果您想编写处理OSGi平台的生命周期层的代码，我建议您跟踪引用，而不是直接查找它。有很多方法可以解决这个问题;我已经写了一个我称之为ServiceMediator的东西。

e.g. for your case (code is under Apache 2 License, Coalevo Project):

例如，您的案例(代码在Apache 2许可下，合并项目):

        import org.osgi.framework.*;

    import javax.xml.parsers.SAXParserFactory;

    import net.wimpi.telnetd.util.Latch;

    /**
     * Implements a mediator pattern class for services from the OSGi container.
     * 

     *
     * @author Dieter Wimberger (wimpi)
     * @version @version@ (@date@)
     */
    class ServiceMediator {

      private BundleContext m_BundleContext;

      private SAXParserFactory m_SAXParserFactory;
      private Latch m_SAXParserFactoryLatch;

      public SAXParserFactory getSAXParserFactory(long wait) {
        try {
          if (wait <0) {
            m_SAXParserFactoryLatch.acquire();
          } else if (wait > 0) {
            m_SAXParserFactoryLatch.attempt(wait);
          }
        } catch (InterruptedException e) {
          e.printStackTrace(System.err);
        }

        return m_SAXParserFactory;
      }//getSAXParserFactory

      public boolean activate(BundleContext bc) {
        //get the context
        m_BundleCOntext= bc;

        m_SAXParserFactoryLatch = createWaitLatch();

        //prepareDefinitions listener
        ServiceListener serviceListener = new ServiceListenerImpl();

        //prepareDefinitions the filter
        String filter = "(objectclass=" + SAXParserFactory.class.getName() + ")";

        try {
          //add the listener to the bundle context.
          bc.addServiceListener(serviceListener, filter);

          //ensure that already registered Service instances are registered with
          //the manager
          ServiceReference[] srl = bc.getServiceReferences(null, filter);
          for (int i = 0; srl != null && i