client/src/main/java/com/att/cadi/locator/DNSLocator.java

   1 /*******************************************************************************\r
   2  * ============LICENSE_START====================================================\r
   3  * * org.onap.aai\r
   4  * * ===========================================================================\r
   5  * * Copyright © 2017 AT&T Intellectual Property. All rights reserved.\r
   6  * * Copyright © 2017 Amdocs\r
   7  * * ===========================================================================\r
   8  * * Licensed under the Apache License, Version 2.0 (the "License");\r
   9  * * you may not use this file except in compliance with the License.\r
  10  * * You may obtain a copy of the License at\r
  11  * * \r
  12  *  *      http://www.apache.org/licenses/LICENSE-2.0\r
  13  * * \r
  14  *  * Unless required by applicable law or agreed to in writing, software\r
  15  * * distributed under the License is distributed on an "AS IS" BASIS,\r
  16  * * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
  17  * * See the License for the specific language governing permissions and\r
  18  * * limitations under the License.\r
  19  * * ============LICENSE_END====================================================\r
  20  * *\r
  21  * * ECOMP is a trademark and service mark of AT&T Intellectual Property.\r
  22  * *\r
  23  ******************************************************************************/\r
  24 package com.att.cadi.locator;\r
  25 \r
  26 import java.io.IOException;\r
  27 import java.net.InetAddress;\r
  28 import java.net.URI;\r
  29 import java.net.URISyntaxException;\r
  30 \r
  31 import com.att.cadi.Access;\r
  32 import com.att.cadi.Locator;\r
  33 import com.att.cadi.LocatorException;\r
  34 import com.att.cadi.Access.Level;\r
  35 \r
  36 public class DNSLocator implements Locator<URI> {\r
  37         private static enum Status {UNTRIED, OK, INVALID, SLOW};\r
  38         private static final int CHECK_TIME = 3000;\r
  39         \r
  40         private String host, protocol;\r
  41         private Access access;\r
  42         private Host[] hosts;\r
  43         private int startPort, endPort;\r
  44         private String suffix;\r
  45         \r
  46         public DNSLocator(Access access, String protocol, String host, String range) {\r
  47                 this.host = host;\r
  48                 this.protocol = protocol;\r
  49                 this.access = access;\r
  50                 int dash = range.indexOf('-');\r
  51                 if(dash<0) {\r
  52                         startPort = endPort = Integer.parseInt(range);\r
  53                 } else {\r
  54                         startPort = Integer.parseInt(range.substring(0,dash));\r
  55                         endPort = Integer.parseInt(range.substring(dash + 1));\r
  56                 }\r
  57                 refresh();\r
  58         }\r
  59 \r
  60         @Override\r
  61         public URI get(Item item) throws LocatorException {\r
  62                 return hosts[((DLItem)item).cnt].uri;\r
  63         }\r
  64 \r
  65         @Override\r
  66         public boolean hasItems() {\r
  67                 for(Host h : hosts) {\r
  68                         if(h.status==Status.OK) {\r
  69                                 return true;\r
  70                         }\r
  71                 }\r
  72                 return false;\r
  73         }\r
  74 \r
  75         @Override\r
  76         public void invalidate(Item item) {\r
  77                 DLItem di = (DLItem)item;\r
  78                 hosts[di.cnt].status = Status.INVALID;\r
  79         }\r
  80 \r
  81         @Override\r
  82         public Item best() throws LocatorException {\r
  83                 // not a good "best"\r
  84                 for(int i=0;i<hosts.length;++i) {\r
  85                         switch(hosts[i].status) {\r
  86                                 case OK:\r
  87                                         return new DLItem(i);\r
  88                                 case INVALID:\r
  89                                         break;\r
  90                                 case SLOW:\r
  91                                         break;\r
  92                                 case UNTRIED:\r
  93                                         try {\r
  94                                                 if(hosts[i].ia.isReachable(CHECK_TIME)) {\r
  95                                                         hosts[i].status = Status.OK;\r
  96                                                         return new DLItem(i);\r
  97                                                 }\r
  98                                         } catch (IOException e) {\r
  99                                                 throw new LocatorException(e);\r
 100                                         }\r
 101                                         break;\r
 102                                 default:\r
 103                                         break;\r
 104                         }\r
 105                 }\r
 106                 throw new LocatorException("No Available URIs for " + host);\r
 107         }\r
 108 \r
 109         @Override\r
 110         public Item first() throws LocatorException {\r
 111                 return new DLItem(0);\r
 112         }\r
 113 \r
 114         @Override\r
 115         public Item next(Item item) throws LocatorException {\r
 116                 DLItem di = (DLItem)item;\r
 117                 if(++di.cnt<hosts.length) {\r
 118                         return di;\r
 119                 } else {\r
 120                         return null;\r
 121                 }\r
 122         }\r
 123 \r
 124         @Override\r
 125         public boolean refresh() {\r
 126                 try {\r
 127                         InetAddress[] ias = InetAddress.getAllByName(host);\r
 128                         Host[] temp = new Host[ias.length * (1 + endPort - startPort)];\r
 129                         int cnt = -1;\r
 130                         for(int j=startPort; j<=endPort; ++j) {\r
 131                                 for(int i=0;i<ias.length;++i) {\r
 132                                         temp[++cnt] = new Host(ias[i], j, suffix);\r
 133                                 }\r
 134                         }\r
 135                         hosts = temp;\r
 136                         return true;\r
 137                 } catch (Exception e) {\r
 138                         access.log(Level.ERROR, e);\r
 139                 }\r
 140                 return false;\r
 141         }\r
 142 \r
 143         private class Host {\r
 144                 private URI uri;\r
 145                 private InetAddress ia;\r
 146                 private Status status;\r
 147                 \r
 148                 public Host(InetAddress inetAddress, int port, String suffix) throws URISyntaxException {\r
 149                         ia = inetAddress;\r
 150                         uri = new URI(protocol,null,inetAddress.getHostAddress(),port,suffix,null,null);\r
 151                         status = Status.UNTRIED;\r
 152                 }\r
 153         }\r
 154         \r
 155         private class DLItem implements Item {\r
 156                 public DLItem(int i) {\r
 157                         cnt = i;\r
 158                 }\r
 159 \r
 160                 private int cnt;\r
 161         }\r
 162         \r
 163         public void destroy() {}\r
 164 }\r