libjava/gnu/java/util/prefs/NodeReader.java

   1 /* NodeReader - Reads and imports preferences nodes from files
   2    Copyright (C) 2001 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38 package gnu.java.util.prefs;
  39
  40 import java.io.BufferedReader;
  41 import java.io.InputStream;
  42 import java.io.InputStreamReader;
  43 import java.io.InputStream;
  44 import java.io.IOException;
  45 import java.io.Reader;
  46
  47 import java.util.prefs.*;
  48
  49 /**
  50  * Reads and imports preferences nodes from files.
  51  *
  52  * @author Mark Wielaard (mark@klomp.org)
  53  */
  54 public class NodeReader {
  55
  56     private final BufferedReader br;
  57     private String line = "";
  58
  59     private final PreferencesFactory factory;
  60
  61     public NodeReader(Reader r, PreferencesFactory factory) {
  62         if(r instanceof BufferedReader) {
  63             br = (BufferedReader) r;
  64         } else {
  65             br = new BufferedReader(r);
  66         }
  67         this.factory = factory;
  68     }
  69
  70     public NodeReader(InputStream is, PreferencesFactory factory) {
  71         this(new InputStreamReader(is), factory);
  72     }
  73
  74     public void importPreferences()
  75                     throws InvalidPreferencesFormatException, IOException
  76     {
  77         readPreferences();
  78     }
  79
  80     private void readPreferences()
  81                     throws InvalidPreferencesFormatException, IOException
  82     {
  83         // Begin starting tag
  84         skipTill("<preferences");
  85
  86         readRoot();
  87
  88         // Ending tag
  89         skipTill("</preferences>");
  90     }
  91
  92     private void readRoot()
  93                     throws InvalidPreferencesFormatException, IOException
  94     {
  95         // Begin starting tag
  96         skipTill("<root");
  97
  98         // type attribute
  99         skipTill("type=\"");
 100         String type = readTill("\"");
 101         Preferences root;
 102         if ("user".equals(type)) {
 103             root = factory.userRoot();
 104         } else if ("system".equals(type)) {
 105             root = factory.systemRoot();
 106         } else {
 107             throw new InvalidPreferencesFormatException("Unknown type: "
 108                                                         + type);
 109         }
 110
 111         // Read root map and subnodes
 112         readMap(root);
 113         readNodes(root);
 114
 115         // Ending tag
 116         skipTill("</root>");
 117     }
 118
 119     private void readNodes(Preferences node)
 120                     throws InvalidPreferencesFormatException, IOException
 121     {
 122         while ("node".equals(nextTag())) {
 123             skipTill("<node");
 124             skipTill("name=\"");
 125             String name = readTill("\"");
 126             Preferences subnode = node.node(name);
 127             System.out.println("Found subnode: " + subnode.absolutePath());
 128             readMap(subnode);
 129             readNodes(subnode);
 130             skipTill("</node>");
 131         }
 132
 133     }
 134
 135     private void readMap(Preferences node)
 136                     throws InvalidPreferencesFormatException, IOException
 137     {
 138         // Begin map tag
 139         skipTill("<map");
 140
 141         // Empty map?
 142         if (line.startsWith("/>")) {
 143             line = line.substring(2);
 144             return;
 145         }
 146
 147         // Map entries
 148         readEntries(node);
 149
 150         // Ending tag
 151         skipTill("</map>");
 152     }
 153
 154     private void readEntries(Preferences node)
 155                     throws InvalidPreferencesFormatException, IOException
 156     {
 157         while ("entry".equals(nextTag())) {
 158             skipTill("<entry");
 159             skipTill("key=\"");
 160             String key = readTill("\"");
 161             skipTill("value=\"");
 162             String value = readTill("\"");
 163             System.out.println("Key: " + key + " Value: " + value);
 164             node.put(key, value);
 165         }
 166     }
 167
 168     private void skipTill(String s)
 169                     throws InvalidPreferencesFormatException, IOException
 170     {
 171         while(true) {
 172             if (line == null)
 173                 throw new InvalidPreferencesFormatException(s + " not found");
 174
 175             int index = line.indexOf(s);
 176             if (index == -1)  {
 177                 line = br.readLine();
 178             } else {
 179                 line = line.substring(index+s.length());
 180                 return;
 181             }
 182         }
 183     }
 184
 185     private String readTill(String s)
 186                     throws InvalidPreferencesFormatException
 187     {
 188         int index = line.indexOf(s);
 189         if (index == -1)
 190                 throw new InvalidPreferencesFormatException(s + " not found");
 191
 192         String read = line.substring(0, index);
 193         line = line.substring(index+s.length());
 194
 195         return read;
 196     }
 197
 198     private String nextTag()
 199                     throws InvalidPreferencesFormatException, IOException
 200     {
 201         while(true) {
 202             if (line == null)
 203                 throw new InvalidPreferencesFormatException("unexpected EOF");
 204
 205             int start = line.indexOf("<");
 206             if (start == -1)  {
 207                 line = br.readLine();
 208             } else {
 209                 // Find end of tag
 210                 int end = start+1;
 211                 while (end != line.length()
 212                        && " \t\r\n".indexOf(line.charAt(end)) == -1) {
 213                     end++;
 214                 }
 215                 // Line now starts at the found tag
 216                 String tag = line.substring(start+1,end);
 217                 line = line.substring(start);
 218                 return tag;
 219             }
 220         }
 221     }
 222
 223 }