datasource/Cached_TextDB_Loader.java

   1 package org.de.metux.datasource;
   2
   3 import java.io.File;
   4 import java.util.Hashtable;
   5 import java.util.Properties;
   6
   7 import org.de.metux.util.TextDB;
   8
   9 public class Cached_TextDB_Loader implements ITextDB_Loader
  10 {
  11     public boolean enabled = true;
  12
  13     Hashtable<String,Properties> cache = null;
  14
  15     public void clearCache()
  16     {
  17         cache = null;
  18     }
  19
  20     public void setCaching(boolean e)
  21     {
  22         enabled = e;
  23     }
  24
  25     private Properties __load(String fn)
  26     {
  27         Properties pr = new Properties();
  28         if (TextDB.LoadIntoHashtable(fn,pr))
  29             return pr;
  30         else
  31             return null;
  32     }
  33
  34     public Properties load(String filename)
  35     {
  36         if (filename == null)
  37             return null;
  38
  39         if (!enabled)
  40             return __load(filename);
  41
  42         Properties pr;
  43
  44         if (cache == null)
  45             cache = new Hashtable<String,Properties>();
  46         else if ((pr = cache.get(filename)) != null)
  47             return pr;
  48
  49         if ((pr = __load(filename)) != null)
  50             cache.put(filename,pr);
  51
  52         return pr;
  53     }
  54
  55     public Properties load(File filename)
  56     {
  57         return load(filename.toString());
  58     }
  59 }