001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package com.iona.fuse.mb.discovery.http;
018
019 import java.io.IOException;
020 import java.io.PrintWriter;
021 import java.util.ArrayList;
022 import java.util.Iterator;
023 import java.util.Map;
024 import java.util.concurrent.ConcurrentHashMap;
025 import java.util.regex.Matcher;
026 import java.util.regex.Pattern;
027
028 import javax.servlet.ServletException;
029 import javax.servlet.http.HttpServlet;
030 import javax.servlet.http.HttpServletRequest;
031 import javax.servlet.http.HttpServletResponse;
032
033 import org.apache.activemq.command.Response;
034 import org.apache.commons.logging.Log;
035 import org.apache.commons.logging.LogFactory;
036
037 public class DiscoveryRegistryServlet extends HttpServlet {
038
039 private static final Log LOG = LogFactory.getLog(HTTPDiscoveryAgent.class);
040 long maxKeepAge = 1000*60*60; // 1 hour.
041 ConcurrentHashMap<String, ConcurrentHashMap<String, Long>> serviceGroups = new ConcurrentHashMap<String, ConcurrentHashMap<String, Long>>();
042
043 @Override
044 protected void doPut(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
045 String group = req.getPathInfo();
046 String service = req.getHeader("service");
047 LOG.debug("Registering: group="+group+", service="+service);
048
049 ConcurrentHashMap<String, Long> services = getServiceGroup(group);
050 services.put(service, System.currentTimeMillis());
051 }
052
053 private ConcurrentHashMap<String, Long> getServiceGroup(String group) {
054 ConcurrentHashMap<String, Long> rc = serviceGroups.get(group);
055 if( rc == null ) {
056 rc = new ConcurrentHashMap<String, Long>();
057 serviceGroups.put(group, rc);
058 }
059 return rc;
060 }
061
062 @Override
063 protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
064 try {
065 long freshness = 1000*30;
066 String p = req.getParameter("freshness");
067 if( p!=null ) {
068 freshness = Long.parseLong(p);
069 }
070
071 String group = req.getPathInfo();
072 LOG.debug("group="+group);
073 ConcurrentHashMap<String, Long> services = getServiceGroup(group);
074 PrintWriter writer = resp.getWriter();
075
076 long now = System.currentTimeMillis();
077 long dropTime = now-maxKeepAge;
078 long minimumTime = now-freshness;
079
080 ArrayList<String> dropList = new ArrayList<String>();
081 for (Map.Entry<String, Long> entry : services.entrySet()) {
082 if( entry.getValue() > minimumTime ) {
083 writer.println(entry.getKey());
084 } else if( entry.getValue() < dropTime ) {
085 dropList.add(entry.getKey());
086 }
087 }
088
089 // We might as well get rid of the really old entries.
090 for (String service : dropList) {
091 services.remove(service);
092 }
093
094
095 } catch (Exception e) {
096 resp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Error occured: "+e);
097 }
098 }
099
100 @Override
101 protected void doDelete(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
102 String group = req.getPathInfo();
103 String service = req.getHeader("service");
104 LOG.debug("Unregistering: group="+group+", service="+service);
105
106 ConcurrentHashMap<String, Long> services = getServiceGroup(group);
107 services.remove(service);
108 }
109
110 }