Java 如何使用OSGi声明性服务正确实现servlet？

我正在尝试（学习如何）使用OSGi提供的声明性服务（DS）创建Servlet（

javax.Servlet.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（2019-03（4.11.0），build id:20190314-1200）上运行时，我使用（

-Dorg.osgi.service.http.port=8080

）在osgi控制台中看到如下内容：

osgi> 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.StdErrLog
2019-05-07 18:22:28.388:INFO:oejs.session:Start Level: Equinox Container: 0d7d3d67-401b-48eb-b016-6e6c0c16352c: DefaultSessionIdManager workerName=node0
2019-05-07 18:22:28.388:INFO:oejs.session:Start Level: Equinox Container: 0d7d3d67-401b-48eb-b016-6e6c0c16352c: No SessionScavenger set, using defaults
2019-05-07 18:22:28.389:INFO:oejs.session:Start Level: Equinox Container: 0d7d3d67-401b-48eb-b016-6e6c0c16352c: node0 Scavenging every 660000ms
2019-05-07 18:22:28.427:INFO:oejs.session:Start Level: Equinox Container: 0d7d3d67-401b-48eb-b016-6e6c0c16352c: node0 Scavenging every 660000ms

现在，当我使用（

http://127.0.0.1:8080/hello

）我得到：

错误404 ProxyServlet:/hello
HTTP错误404
访问/hello时出现问题。原因:
@Component(service = Servlet.class, property = {"osgi.http.whiteboard.servlet.pattern=/hello/*" })

ProxyServlet:/hello

---

如何解决此问题？

使用

osgi.http.whiteboard.servlet.pattern

属性代替

别名

：

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

或者，对于当前的osgi概要依赖项（版本7.0.0），您可以使用

@org.osgi.service.http.whiteboard.propertytypes.HttpWhiteboardServletPattern

注释，如下所示：

---

请参见此处包含所有属性的表：

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