AgentResource.java

/**
 *  Copyright (C) 2008 Progress Software, Inc. All rights reserved.
 *  http://fusesource.com
 *
 *  The software in this package is published under the terms of the AGPL license
 *  a copy of which has been included with this distribution in the license.txt file.
 */
package org.fusesource.cloudmix.agent.resources;


import java.io.InputStream;
import java.net.URI;

import javax.annotation.PostConstruct;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;

import javax.ws.rs.Consumes;
import javax.ws.rs.DELETE;
import javax.ws.rs.GET;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.UriInfo;

import javax.xml.ws.wsaddressing.W3CEndpointReference;

import com.sun.jersey.spi.inject.Inject;
import com.sun.jersey.spi.resource.Singleton;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.fusesource.cloudmix.agent.EndpointRegistry;
import org.fusesource.cloudmix.agent.webapp.GridAgentWebapp;


@Path("/agent")
@Singleton
public class AgentResource implements LifecycleObserver {
    private static final transient Log LOG = LogFactory.getLog(AgentResource.class);

    @Inject
    private GridAgentWebapp webapp;
    @Inject
    private EndpointRegistry endpointRegistry;
    
    @Context
    private UriInfo uriInfo;
    
    @Context
    private ServletConfig config;

    /**
     * Add an endpoint to the agent details.
     *
     * @param id the endpoint key
     * @param ref the endpoint reference
     * @return a response with appropriate status
     */
    @PUT
    @Path("endpoint/{id}")
    @Consumes("application/xml")
    public Response addEndpoint(@PathParam("id")String id,
                                W3CEndpointReference ref) {
        endpointRegistry.addEndpoint(id, ref);
        URI uri = uriInfo.getAbsolutePath();
        return Response.created(uri).build();       
    }
    
    /**
     * Remove an endpoint from the agent details.
     *
     * @param id the endpoint key
     * @return a response with appropriate status
     */
    @DELETE
    @Path("endpoint/{id}")
    public Response removeEndpoint(@PathParam("id")String id) {
        LOG.info("removing endpoint: " + id);
        boolean exists = endpointRegistry.removeEndpoint(id);
        return exists ? Response.ok().build() : Response.status(404).build(); 
    }

    /**
     * Retrieve the agent status.
     *
     * @return an appropriate status summary in HTML
     */    
    @GET
    @Path("status")
    @Produces("text/html")
    public String getStatus() {
        return webapp.getStatus();
    }
    
    /**
     * Retrieve an image from the agent webapp.
     *
     * @return a response encapculating an image stream
     */  
    @GET
    @Path("images/{image}")
    @Produces("image/gif")
    public Response getImage(@PathParam("image")String image) {
        String res = GridAgentWebapp.IMAGES_ROOT + image;
        InputStream is = config.getServletContext().getResourceAsStream(res);
        return is != null 
               ? Response.ok().entity(is).build() 
               : Response.status(404).build(); 
    }
    
    /**
     * Retrieve the sytle-sheet for the agent webapp.
     *
     * @return a response encapculating the stylesheet
     */ 
    @GET
    @Path(GridAgentWebapp.STYLESHEET_HREF)
    @Produces("text/xml")
    public Response getStyleSheet() {
        String res = GridAgentWebapp.STYLESHEET_HREF;
        InputStream is = config.getServletContext().getResourceAsStream(res);
        return Response.ok().entity(is).build();
    }

    /**
     * Injection setter for grid agent webapp
     *
     * @param webapp grid agent webapp
     */
    public void setGridAgentWebapp(GridAgentWebapp gawebapp) {
        this.webapp = gawebapp;
    }

    /**
     * Injection setter for the endpoint registry
     *
     * @param endpointRegistry the endpoint registry
     */
    public void setEndpointRegistry(EndpointRegistry endpointRegistry) {
        this.endpointRegistry = endpointRegistry;
    }

    /**
     * Setter for the URI info
     *
     * @param uriInfo the URI info
     */
    public void setUriInfo(UriInfo uriInfo) {
        this.uriInfo = uriInfo;
    }

    /**
     * Setter for servlet config
     *
     * @param config servlet config
     */
    public void setConfig(ServletConfig config) {
        this.config = config;
    }

    @PostConstruct
    public void init() {
        try {
            webapp.init(config);
        } catch (ServletException se) {
            LOG.warn("webapp init failed", se);
        }
    }

    /**
     * Work-around for @PreDestroy annotation seemingly not being honoured.
     */
    public void destroy() {
        webapp.destroy();
    }

}