Equinox OSGi应用嵌入Jersey框架搭建REST服务

2023-08-26 11:48:10

原文地址：https://www.cnblogs.com/kira2will/p/5040264.html

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

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://*.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://*.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

原文地址：https://www.cnblogs.com/kira2will/p/5040264.html

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