com.netflix.eureka.resources.ApplicationResource Maven / Gradle / Ivy

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/*
 * Copyright 2012 Netflix, Inc.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */

package com.netflix.eureka.resources;

import javax.ws.rs.Consumes;
import javax.ws.rs.GET;
import javax.ws.rs.HeaderParam;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.Status;

import com.netflix.appinfo.InstanceInfo;
import com.netflix.eureka.CurrentRequestVersion;
import com.netflix.eureka.PeerAwareInstanceRegistry;
import com.netflix.eureka.Version;
import com.netflix.eureka.cluster.PeerEurekaNode;
import com.netflix.eureka.resources.ResponseCache.Key;
import com.netflix.eureka.resources.ResponseCache.KeyType;
import com.netflix.eureka.util.EurekaMonitors;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * A jersey resource that handles request related to a particular
 * {@link com.netflix.discovery.shared.Application}.
 *
 * @author Karthik Ranganathan, Greg Kim
 *
 */
@Produces({"application/xml", "application/json"})
public class ApplicationResource {
    private static final Logger logger = LoggerFactory
            .getLogger(ApplicationResource.class);

    private final PeerAwareInstanceRegistry registry = PeerAwareInstanceRegistry
            .getInstance();

    String appName;

    public ApplicationResource(String appName) {
        this.appName = appName.toUpperCase();
    }

    /**
     * Gets information about a particular {@link com.netflix.discovery.shared.Application}.
     *
     * @param version
     *            the version of the request.
     * @param acceptHeader
     *            the accept header of the request to indicate whether to serve
     *            JSON or XML data.
     * @return the response containing information about a particular
     *         application.
     */
    @GET
    public Response getApplication(@PathParam("version") String version,
                                   @HeaderParam("Accept") final String acceptHeader) {
        if (!PeerAwareInstanceRegistry.getInstance().shouldAllowAccess(false)) {
            return Response.status(Status.FORBIDDEN).build();
        }

        EurekaMonitors.GET_APPLICATION.increment();

        CurrentRequestVersion.set(Version.toEnum(version));
        KeyType keyType = KeyType.JSON;
        if (acceptHeader == null || !acceptHeader.contains("json")) {
            keyType = KeyType.XML;
        }

        Key cacheKey = new Key(Key.EntityType.Application, appName, keyType, CurrentRequestVersion.get());

        String payLoad = ResponseCache.getInstance().get(cacheKey);

        if (payLoad != null) {
            logger.debug("Found: {}", appName);
            return Response.ok(payLoad).build();
        } else {
            logger.debug("Not Found: {}", appName);
            return Response.status(Status.NOT_FOUND).build();
        }
    }

    /**
     * Gets information about a particular instance of an application.
     *
     * @param id
     *            the unique identifier of the instance.
     * @return information about a particular instance.
     */
    @Path("{id}")
    public InstanceResource getInstanceInfo(@PathParam("id") String id) {
        return new InstanceResource(this, id);
    }

    /**
     * Registers information about a particular instance for an
     * {@link com.netflix.discovery.shared.Application}.
     *
     * @param info
     *            {@link InstanceInfo} information of the instance.
     * @param isReplication
     *            a header parameter containing information whether this is
     *            replicated from other nodes.
     */
    @POST
    @Consumes({"application/json", "application/xml"})
    public void addInstance(InstanceInfo info,
                            @HeaderParam(PeerEurekaNode.HEADER_REPLICATION) String isReplication) {
        registry.register(info, "true".equals(isReplication));
    }

    /**
     * Returns the application name of a particular application.
     *
     * @return the application name of a particular application.
     */
    String getName() {
        return appName;
    }

}