如何使用 OSGi 声明式服务正确实现 servlet？

Question

我正在尝试（学习如何）javax.servlet.Servlet使用 OSGi 提供的声明性服务（DS）创建一个 Servlet（），如下所示：import java.io.IOException;import javax.servlet.Servlet;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.osgi.service.component.annotations.Component;@Component(service = Servlet.class, property = { "alias:String=/hello" }, immediate = true)public class LogsHTTPServlet extends HttpServlet {    private static final long serialVersionUID = 2302372200114479484L;    @Override    public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {        try {            resp.setContentType("text/plain");            resp.getWriter().println("It works!");        } catch (Exception e) {            e.printStackTrace();        }        resp.setStatus(200);    }}当我在Eclipse (2019-03 (4.11.0), build id: 20190314-1200)上使用自定义运行配置在此目标平台上运行项目时，我使用此 VM 参数设置（和其他必需的依赖项）（)，我在 osgi 控制台中看到如下内容： org.eclipse.jetty.server-Dorg.osgi.service.http.port=8080osgi> 2019-05-07 18:22:28.236:INFO::Start Level: Equinox Container: 0d7d3d67-401b-48eb-b016-6e6c0c16352c: Logging initialized @1590ms to org.eclipse.jetty.util.log.StdErrLog2019-05-07 18:22:28.388:INFO:oejs.session:Start Level: Equinox Container: 0d7d3d67-401b-48eb-b016-6e6c0c16352c: DefaultSessionIdManager workerName=node02019-05-07 18:22:28.388:INFO:oejs.session:Start Level: Equinox Container: 0d7d3d67-401b-48eb-b016-6e6c0c16352c: No SessionScavenger set, using defaults2019-05-07 18:22:28.389:INFO:oejs.session:Start Level: Equinox Container: 0d7d3d67-401b-48eb-b016-6e6c0c16352c: node0 Scavenging every 660000ms2019-05-07 18:22:28.427:INFO:oejs.session:Start Level: Equinox Container: 0d7d3d67-401b-48eb-b016-6e6c0c16352c: node0 Scavenging every 660000ms我该如何解决这个问题？

Answer 1

而不是alias使用该osgi.http.whiteboard.servlet.pattern属性：

@Component(service = Servlet.class, property = {"osgi.http.whiteboard.servlet.pattern=/hello/*" })

或者，使用当前的 osgi 纲要依赖项（版本 7.0.0），您可以使用如下@org.osgi.service.http.whiteboard.propertytypes.HttpWhiteboardServletPattern注释：

@Component(service=Servlet.class)
@org.osgi.service.http.whiteboard.propertytypes.HttpWhiteboardServletPattern("/hello/*")

见https://osgi.org/specification/osgi.cmpn/7.0.0/service.http.whiteboard.html#service.http.whiteboard-i21223311