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 org.apache.activemq.transport.discovery.http; 018 019 import java.io.IOException; 020 import java.io.PrintWriter; 021 import java.util.ArrayList; 022 import java.util.Map; 023 import java.util.concurrent.ConcurrentHashMap; 024 025 import javax.servlet.ServletException; 026 import javax.servlet.http.HttpServlet; 027 import javax.servlet.http.HttpServletRequest; 028 import javax.servlet.http.HttpServletResponse; 029 030 import org.apache.commons.logging.Log; 031 import org.apache.commons.logging.LogFactory; 032 033 public class DiscoveryRegistryServlet extends HttpServlet { 034 035 private static final Log LOG = LogFactory.getLog(HTTPDiscoveryAgent.class); 036 long maxKeepAge = 1000*60*60; // 1 hour. 037 ConcurrentHashMap<String, ConcurrentHashMap<String, Long>> serviceGroups = new ConcurrentHashMap<String, ConcurrentHashMap<String, Long>>(); 038 039 @Override 040 protected void doPut(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { 041 String group = req.getPathInfo(); 042 String service = req.getHeader("service"); 043 LOG.debug("Registering: group="+group+", service="+service); 044 045 ConcurrentHashMap<String, Long> services = getServiceGroup(group); 046 services.put(service, System.currentTimeMillis()); 047 } 048 049 private ConcurrentHashMap<String, Long> getServiceGroup(String group) { 050 ConcurrentHashMap<String, Long> rc = serviceGroups.get(group); 051 if( rc == null ) { 052 rc = new ConcurrentHashMap<String, Long>(); 053 serviceGroups.put(group, rc); 054 } 055 return rc; 056 } 057 058 @Override 059 protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { 060 try { 061 long freshness = 1000*30; 062 String p = req.getParameter("freshness"); 063 if( p!=null ) { 064 freshness = Long.parseLong(p); 065 } 066 067 String group = req.getPathInfo(); 068 LOG.debug("group="+group); 069 ConcurrentHashMap<String, Long> services = getServiceGroup(group); 070 PrintWriter writer = resp.getWriter(); 071 072 long now = System.currentTimeMillis(); 073 long dropTime = now-maxKeepAge; 074 long minimumTime = now-freshness; 075 076 ArrayList<String> dropList = new ArrayList<String>(); 077 for (Map.Entry<String, Long> entry : services.entrySet()) { 078 if( entry.getValue() > minimumTime ) { 079 writer.println(entry.getKey()); 080 } else if( entry.getValue() < dropTime ) { 081 dropList.add(entry.getKey()); 082 } 083 } 084 085 // We might as well get rid of the really old entries. 086 for (String service : dropList) { 087 services.remove(service); 088 } 089 090 091 } catch (Exception e) { 092 resp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Error occured: "+e); 093 } 094 } 095 096 @Override 097 protected void doDelete(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { 098 String group = req.getPathInfo(); 099 String service = req.getHeader("service"); 100 LOG.debug("Unregistering: group="+group+", service="+service); 101 102 ConcurrentHashMap<String, Long> services = getServiceGroup(group); 103 services.remove(service); 104 } 105 106 }