src/com/lavans/luz2/lremote/selector/SelectorFactory.java

   1 package com.lavans.luz2.lremote.selector;\r
   2 \r
   3 \r
   4 import java.lang.reflect.Constructor;\r
   5 import java.util.Collections;\r
   6 import java.util.HashMap;\r
   7 import java.util.Map;\r
   8 \r
   9 import org.apache.commons.logging.Log;\r
  10 import org.apache.commons.logging.LogFactory;\r
  11 \r
  12 import com.lavans.luz2.lremote.annotation.LRemote;\r
  13 import com.lavans.luz2.lremote.connector.ConnectManager;\r
  14 import com.lavans.luz2.lremote.node.RemoteNodeGroup;\r
  15 import com.lavans.luz2.lremote.selector.impl.GroupSelector;\r
  16 import com.lavans.luz2.lremote.selector.impl.OrderedSelector;\r
  17 import com.lavans.luz2.lremote.selector.impl.OthersSelector;\r
  18 \r
  19 /**\r
  20  * Selector factory class.\r
  21  * Selector is instanced for each RemoteNodeGroup and it is stateful.\r
  22  * SelectorFactory caches all instance of selector.\r
  23  *\r
  24  * @author dobashi\r
  25  *\r
  26  */\r
  27 public class SelectorFactory {\r
  28         /** logger */\r
  29         private static Log logger = LogFactory.getLog(ConnectManager.class.getName());\r
  30 \r
  31         /** Cache of all selector instance */\r
  32         private static Map<Class<? extends Selector>, Map<RemoteNodeGroup, Selector>> selectorMap = Collections.synchronizedMap(new HashMap<Class<? extends Selector>, Map<RemoteNodeGroup,Selector>>());\r
  33 \r
  34         /**\r
  35          * Get selector.\r
  36          *\r
  37          * @param lremote\r
  38          * @param group\r
  39          * @return\r
  40          */\r
  41         public static Selector getSelector(LRemote lremote, RemoteNodeGroup group){\r
  42                 // connect condition\r
  43                 LRemote.Selector lremoteSelector = lremote.selector();\r
  44 \r
  45                 // search selector class\r
  46                 Class<? extends Selector> selectorClass = null;\r
  47                 switch (lremoteSelector){\r
  48                         case ORDERED:\r
  49                                 selectorClass = OrderedSelector.class;\r
  50                                 break;\r
  51                         case GROUP:\r
  52                                 selectorClass = GroupSelector.class;\r
  53                                 break;\r
  54                         case OTHERS:\r
  55                                 selectorClass = OthersSelector.class;\r
  56                                 break;\r
  57                         default:\r
  58                                 // TODO from String\r
  59                 }\r
  60 \r
  61                 // check class is valid\r
  62                 // throw NoSuchSelectorException?\r
  63                 if(selectorClass == null){\r
  64                         return null;\r
  65                 }\r
  66 \r
  67                 // Search groupMap for this class.\r
  68                 Map<RemoteNodeGroup, Selector> groupMap = selectorMap.get(selectorClass);\r
  69                 if(groupMap==null){\r
  70                         // create new one\r
  71                         groupMap = Collections.synchronizedMap(new HashMap<RemoteNodeGroup, Selector>());\r
  72                         selectorMap.put(selectorClass, groupMap);\r
  73                 }\r
  74 \r
  75                 // Search selector instance for this group.\r
  76                 Selector selector = groupMap.get(group);\r
  77                 if(selector==null){\r
  78                         try {\r
  79                                 Constructor<? extends Selector> constructor = selectorClass.getConstructor(RemoteNodeGroup.class);\r
  80                                 selector = constructor.newInstance(group);\r
  81                                 // save cache to map\r
  82                                 groupMap.put(group, selector);\r
  83                         } catch (Exception e) {\r
  84                                 logger.error("", e);\r
  85                         }\r
  86                 }\r
  87 \r
  88                 return selector;\r
  89         }\r
  90 }\r