原创：Equinox OSGi应用嵌入Jersey框架搭建REST服务

一、环境

eclipse版本：eclipse-luna 4.4

jre版本：1.8

二、Equinox OSGi应用嵌入Jersey框架搭建REST服务

1.新建插件工程HelloWebOSGI

a.

b.

c.

d.在新建的工程中新建文件夹lib，其中放入附件中的jar包（见文末）,全部添加到工程Build Path中。

2.配置运行环境

a.配置引入包、依赖插件

b.选择Run->Run Configuration，new一个环境

保留图中TargetPlatform中的16个Bundle。

c.在Run Configuration中设置参数

友情提示：如果有其他异常请查看提示信息，利用 http://www.aolsearch.com/ 查询提示信息（英文），如果发现http://stackoverflow.com/这个网站有相同提问，基本就知道答案近在咫尺了。

比如笔者遇到的问题：Root exception:java.lang.IllegalStateException: Workbench has not been created yet.

解决方法就是在http://stackoverflow.com/questions/13773582/workbench-has-not-been-created-yet-error-in-eclipse-plugin-programming中找到的。

d.在MANIFEST.MF(META-INF)文件中将lib文件夹中的包都引入如下图中。

3.添加代码

Activator_sample.java

 package helloworldosgi;

 import java.util.Dictionary;
 import java.util.HashMap;
 import java.util.Hashtable;
 import java.util.logging.Logger;

 import javax.servlet.ServletException;

 import org.glassfish.jersey.servlet.ServletContainer;
 import org.osgi.framework.BundleActivator;
 import org.osgi.framework.BundleContext;
 import org.osgi.framework.ServiceReference;
 import org.osgi.service.event.Event;
 import org.osgi.service.event.EventAdmin;
 import org.osgi.service.http.HttpService;
 import org.osgi.service.http.NamespaceException;
 import org.osgi.util.tracker.ServiceTracker;

 /*
  * BundleActivator:让你能够捕捉到bundle的start和stop事件，并对这两个事件作出自定义的反应。
  */
 public class Activator_sample implements BundleActivator {
     private BundleContext bc;
     @SuppressWarnings("rawtypes")
     private ServiceTracker tracker;
     private HttpService httpService = null;
     private static final Logger logger = Logger.getLogger(Activator.class.getName());

     /**
      * URL前缀
      */
     public static final String CONTEXT_PATH = "/rest/json";

     /*
      * BundleContext:一个bundle在框架中的执行时上下文，这个上下文提供了和框架进行交互的方法。
      * @see org.osgi.framework.BundleActivator#start(org.osgi.framework.BundleContext)
      */
     @SuppressWarnings({ "unchecked", "rawtypes" })
     @Override
     public synchronized void start(BundleContext bundleContext)    throws Exception {
         this.bc = bundleContext;
         logger.info("STARTING HTTP SERVICE BUNDLE");

         this.tracker = new ServiceTracker(this.bc, HttpService.class.getName(),    null) {
             @Override
             public Object addingService(ServiceReference serviceRef) {
                 httpService = (HttpService) super.addingService(serviceRef);
                 registerServlets();
                 return httpService;
             }

             @Override
             public void removedService(ServiceReference ref, Object service) {
                 if (httpService == service) {
                     unregisterServlets();
                     httpService = null;
                 }
                 super.removedService(ref, service);
             }
         };

         this.tracker.open();

         logger.info("HTTP SERVICE BUNDLE STARTED");
     }

     /*
      * BundleContext:一个bundle在框架中的执行时上下文，这个上下文提供了和框架进行交互的方法。
      * @see org.osgi.framework.BundleActivator#stop(org.osgi.framework.BundleContext)
      */
     @Override
     public synchronized void stop(BundleContext bundleContext) throws Exception {
         this.tracker.close();
     }

     private void registerServlets() {
         try {
             rawRegisterServlets();
         } catch (InterruptedException | NamespaceException | ServletException ie) {
             throw new RuntimeException(ie);
         }
     }

     private void rawRegisterServlets() throws ServletException,    NamespaceException, InterruptedException {
         logger.info("JERSEY BUNDLE: REGISTERING SERVLETS");
         logger.info("JERSEY BUNDLE: HTTP SERVICE = " + httpService.toString());

         // TODO - temporary workaround
         // This is a workaround related to issue JERSEY-2093; grizzly (1.9.5)
         // needs to have the correct context
         // classloader set
         ClassLoader myClassLoader = getClass().getClassLoader();
         ClassLoader originalContextClassLoader = Thread.currentThread()
                 .getContextClassLoader();
         try {
             Thread.currentThread().setContextClassLoader(myClassLoader);
             httpService.registerServlet(CONTEXT_PATH, new ServletContainer(),
                     getJerseyServletParams(), null);
             httpService.registerResources(CONTEXT_PATH + "/hello", "/webroot", null);//前面必须带“/”，后面不一定
         } finally {
             Thread.currentThread().setContextClassLoader(
                     originalContextClassLoader);
         }
         // END of workaround - after grizzly updated to the recent version, only
         // the inner call from try block will remain:
         // httpService.registerServlet("/jersey-http-service", new
         // ServletContainer(), getJerseyServletParams(), null);

         sendAdminEvent();
         logger.info("JERSEY BUNDLE: SERVLETS REGISTERED");
     }

     @SuppressWarnings("serial")
     private void sendAdminEvent() {
         @SuppressWarnings("rawtypes")
         ServiceReference eaRef = bc.getServiceReference(EventAdmin.class
                 .getName());
         if (eaRef != null) {
             @SuppressWarnings("unchecked")
             EventAdmin ea = (EventAdmin) bc.getService(eaRef);
             ea.sendEvent(new Event("jersey/test/DEPLOYED",
                     new HashMap<String, String>() {
                         {
                             put("context-path", "/");
                         }
                     }));
             bc.ungetService(eaRef);
         }
     }

     private void unregisterServlets() {
         if (this.httpService != null) {
             logger.info("JERSEY BUNDLE: UNREGISTERING SERVLETS");
             httpService.unregister(CONTEXT_PATH);
             logger.info("JERSEY BUNDLE: SERVLETS UNREGISTERED");
         }
     }

     private Dictionary<String, String> getJerseyServletParams() {
         Dictionary<String, String> jerseyServletParams = new Hashtable<>();
         jerseyServletParams.put("javax.ws.rs.Application",
                 RestApplication.class.getName());
         logger.info("kira2will" + RestApplication.class.getName());
         return jerseyServletParams;
     }

 }

StatusService.java

 package helloworldosgi;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.logging.Logger;

 import javax.ws.rs.GET;
 import javax.ws.rs.Path;
 import javax.ws.rs.PathParam;
 import javax.ws.rs.Produces;
 import javax.ws.rs.core.MediaType;

 import data.Node;

 @Path("/status")
 public class StatusService {

     private static final Logger logger = Logger.getLogger(StatusService.class.getName());

     @GET
     @Produces(MediaType.APPLICATION_JSON)
     public Node getStatus(){

         List<Node> nodes = new ArrayList<Node>();
         Node node = new Node("001", "60800","192.168.1.1","0","92","92","chizhou","50ms","hw");
         Node nothingNode = new Node("null","null","null","null","null","null","null","null","null");
         //nodes.add(node);
         nodes.add(node);
         logger.info(node.getName());
         return node;
     }

     @Path("/{id}")
     @GET
     @Produces(MediaType.APPLICATION_JSON)
     public Node getID(@PathParam("id") int id){
         List<Node> nodes = new ArrayList<Node>();

         nodes.add(new Node("null","null","null","null","null","null","null","null","null"));
         nodes.add(new Node("001", "60600","192.168.1.1","0","92","92","tonglin","50ms","hw"));
         nodes.add(new Node("002", "60600","192.168.1.1","0","92","92","tonglin","50ms","hw"));
         nodes.add(new Node("003", "60600","192.168.1.1","0","92","92","tonglin","50ms","hw"));
         nodes.add(new Node("004", "60600","192.168.1.1","0","92","92","tonglin","50ms","hw"));
         nodes.add(new Node("005", "60600","192.168.1.1","0","92","92","tonglin","50ms","hw"));        

         int defaultIndex = 0;
         if ( (id < 1) || (id > nodes.size() - 1) ){
             logger.info(nodes.get(defaultIndex).getId());
             return nodes.get(defaultIndex);
         }
         else{
             logger.info(nodes.get(id).getId());
             return nodes.get(id);
         }
     }
 }

RestApplication.java

 package helloworldosgi;

 import java.util.HashSet;
 import java.util.Set;

 import javax.ws.rs.core.Application;

 import com.fasterxml.jackson.jaxrs.json.JacksonJsonProvider;

 public class RestApplication extends Application {

     @Override
     public Set<Class<?>> getClasses() {
         Set<Class<?>> result = new HashSet<Class<?>>();

         result.add(JacksonJsonProvider.class);

         result.add(StatusService.class);

         return result;
     }
 }

Node.java

 package data;

 import javax.xml.bind.annotation.XmlRootElement;

 @XmlRootElement
 public class Node {

     private String id;
     private String name;
     private String admin_ip;
     private String admin_status;
     private String longitude;
     private String latitude;
     private String location;
     private String latency;
     private String vendor_name;

     public Node(String id,
                 String name,
                 String admin_ip,
                 String admin_status,
                 String longitude,
                 String latitude,
                 String location,
                 String latency,
                 String vendor_name
                 ){
         this.id = id;
         this.name = name;
         this.admin_ip = admin_ip;
         this.admin_status = admin_status;
         this.longitude = longitude;
         this.latitude = latitude;
         this.location = location;
         this.latency = latency;
         this.vendor_name = vendor_name;
     }
     public String getId() {
         return id;
     }

     public void setId(String id) {
         this.id = id;
     }

     public String getName() {
         return name;
     }

     public void setName(String name) {
         this.name = name;
     }

     public String getAdmin_ip() {
         return admin_ip;
     }

     public void setAdmin_ip(String admin_ip) {
         this.admin_ip = admin_ip;
     }

     public String getAdmin_status() {
         return admin_status;
     }

     public void setAdmin_status(String admin_status) {
         this.admin_status = admin_status;
     }

     public String getLongitude() {
         return longitude;
     }

     public void setLongitude(String longitude) {
         this.longitude = longitude;
     }

     public String getLatitude() {
         return latitude;
     }

     public void setLatitude(String latitude) {
         this.latitude = latitude;
     }

     public String getLocation() {
         return location;
     }

     public void setLocation(String location) {
         this.location = location;
     }

     public String getLatency() {
         return latency;
     }

     public void setLatency(String latency) {
         this.latency = latency;
     }

     public String getVendor_name() {
         return vendor_name;
     }

     public void setVendor_name(String vendor_name) {
         this.vendor_name = vendor_name;
     }
 }

4.浏览器中输入 http://localhost:8080/rest/json/status 即可访问public Node getStatus() 返回值。

或者输入 http://localhost:8080/rest/json/status/2 即可访问public Node getID(@PathParam("id") int id)返回值。

关于@Path @Get @PathParam 参考 http://www.docin.com/p-317614298.html 第七页。

http://download.csdn.net/detail/kira_will/9729055