util/VersionStack.java

   1
   2 package org.de.metux.util;
   3
   4 import java.util.Hashtable;
   5 import java.util.Enumeration;
   6
   7 public class VersionStack
   8 {
   9     Hashtable index = new Hashtable();
  10
  11     public VersionStack()
  12     {
  13     }
  14
  15     public VersionStack(String[] v)
  16     {
  17         for (int x=0; x<v.length; x++)
  18             if (v[x]!=null)
  19                 add(new Version(v[x]));
  20     }
  21
  22     public VersionStack(Version[] v)
  23     {
  24         for (int x=0; x<v.length; x++)
  25             if (v[x]!=null)
  26                 add(v[x]);
  27     }
  28
  29     public Version[] getVersions()
  30     {
  31         if (index.size()==0)
  32             return null;
  33
  34         Version list[] = new Version[index.size()];
  35         int x=0;
  36         for (Enumeration e=index.keys(); e.hasMoreElements();)
  37             list[x++] = (Version)index.get((Version)e.nextElement());
  38         return list;
  39     }
  40
  41     public String toString()
  42     {
  43         if (index.size()==0)
  44             return null;
  45
  46         String s = null;
  47         for (Enumeration e=index.keys(); e.hasMoreElements();)
  48         {
  49             Version v = (Version)index.get((Version)e.nextElement());
  50             s = ((s==null)?"":s+" ")+v;
  51         }
  52
  53         return s;
  54     }
  55
  56     public boolean containsVersion(Version v)
  57     {
  58         Version v2 = (Version)index.get(v);
  59         if (v2==null)
  60             return false;
  61
  62         if (v2.equals(v))
  63             return true;
  64
  65         throw new RuntimeException("ugh: index mismatch: "+v2+" - "+v);
  66     }
  67
  68     public boolean add(Version nv)
  69     {
  70         index.put(nv,nv);
  71         return true;
  72     }
  73
  74     public Version[] getLowers(Version delim)
  75     {
  76         VersionStack st = new VersionStack();
  77         divide(delim,st,null);
  78         return st.getVersions();
  79     }
  80
  81     public Version[] getHighers(Version delim)
  82     {
  83         VersionStack st = new VersionStack();
  84         divide(delim,null,st);
  85         return st.getVersions();
  86     }
  87
  88     public int size()
  89     {
  90         return index.size();
  91     }
  92
  93     public void divide(Version delim, VersionStack lowers, VersionStack highers)
  94     {
  95         for (Enumeration e=index.keys(); e.hasMoreElements(); )
  96         {
  97             Version v = (Version)index.get((Version)e.nextElement());
  98             switch (v.compareTo(delim))
  99             {
 100                 case 0:  break;
 101                 case -1:
 102                     if (lowers!=null)  lowers.add(v);  break;
 103                 case 1:
 104                     if (highers!=null) highers.add(v); break;
 105             }
 106         }
 107     }
 108 }
 109