Source for gnu.java.net.IndexListParser

   1: /* IndexListParser.java --
   2:    Copyright (C) 2006 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., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 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: 
  39: package gnu.java.net;
  40: 
  41: import java.io.BufferedReader;
  42: import java.io.InputStreamReader;
  43: import java.net.URL;
  44: import java.util.HashSet;
  45: import java.util.LinkedHashMap;
  46: import java.util.Set;
  47: import java.util.jar.JarFile;
  48: 
  49: /**
  50:  * The INDEX.LIST file contains sections each separated by a blank line.
  51:  * Each section defines the content of a jar, with a
  52:  * header defining the jar file path name, followed by a list of paths.
  53:  * The jar file paths are relative to the codebase of the root jar.
  54:  *
  55:     Specification
  56:     index file :            version-info blankline section*
  57:     version-info :          JarIndex-Version: version-number
  58:     version-number :        digit+{.digit+}*
  59:     section :               body blankline
  60:     body :                  header name*
  61:     header :                char+.jar newline
  62:     name :                  char+ newline
  63: 
  64:  * @author langel at redhat dot com
  65:  */
  66: public class IndexListParser
  67: {
  68:   public static final String JAR_INDEX_FILE = "META-INF/INDEX.LIST";
  69:   public static final String JAR_INDEX_VERSION_KEY = "JarIndex-Version: ";
  70: 
  71:   double versionNumber;
  72:   // Map each jar to the prefixes defined for the jar.
  73:   // This is intentionally kept in insertion order.
  74:   LinkedHashMap<URL, Set<String>> prefixes
  75:     = new LinkedHashMap<URL, Set<String>>();
  76: 
  77:   /**
  78:    * Parses the given jarfile's INDEX.LIST file if it exists.
  79:    *
  80:    * @param jarfile - the given jar file
  81:    * @param baseJarURL - the codebase of the jar file
  82:    * @param baseURL - the base url for the headers
  83:    */
  84:   public IndexListParser(JarFile jarfile, URL baseJarURL, URL baseURL)
  85:   {
  86:     try
  87:     {
  88:     // Parse INDEX.LIST if it exists
  89:     if (jarfile.getEntry(JAR_INDEX_FILE) != null)
  90:       {
  91:         BufferedReader br = new BufferedReader(new InputStreamReader(new URL(baseJarURL,
  92:                                                                              JAR_INDEX_FILE).openStream()));
  93: 
  94:         // Must start with version info
  95:         String line = br.readLine();
  96:         if (!line.startsWith(JAR_INDEX_VERSION_KEY))
  97:           return;
  98:         versionNumber = Double.parseDouble(line.substring(JAR_INDEX_VERSION_KEY.length()).trim());
  99: 
 100:         // Blank line must be next
 101:         line = br.readLine();
 102:         if (! "".equals(line))
 103:           {
 104:             clearAll();
 105:             return;
 106:           }
 107: 
 108:         // May contain sections.
 109:         while ((line = br.readLine()) != null)
 110:           {
 111:             URL jarURL = new URL(baseURL, line);
 112:             HashSet<String> values = new HashSet<String>();
 113: 
 114:             // Read the names in the section.
 115:             while ((line = br.readLine()) != null)
 116:               {
 117:                 // Stop at section boundary.
 118:                 if ("".equals(line))
 119:                   break;
 120:                 values.add(line.trim());
 121:               }
 122:             prefixes.put(jarURL, values);
 123:             // Might have seen an early EOF.
 124:             if (line == null)
 125:               break;
 126:           }
 127: 
 128:         br.close();
 129:       }
 130:     else
 131:       {
 132:         // INDEX.LIST does not exist
 133:         clearAll();
 134:       }
 135:     }
 136:     catch (Exception ex)
 137:     {
 138:       clearAll();
 139:     }
 140:   }
 141: 
 142:   /**
 143:    * Clears all the variables. This is called when parsing fails.
 144:    */
 145:   void clearAll()
 146:   {
 147:     versionNumber = 0;
 148:     prefixes = null;
 149:   }
 150: 
 151:   /**
 152:    * Gets the version info for the file.
 153:    *
 154:    * @return the version info.
 155:    */
 156:   public String getVersionInfo()
 157:   {
 158:     return JAR_INDEX_VERSION_KEY + getVersionNumber();
 159:   }
 160: 
 161:   /**
 162:    * Gets the version number of the file.
 163:    *
 164:    * @return the version number.
 165:    */
 166:   public double getVersionNumber()
 167:   {
 168:     return versionNumber;
 169:   }
 170: 
 171:   /**
 172:    * Gets the map of all the headers found in the file.
 173:    * The keys in the map are URLs of jars.  The values in the map
 174:    * are Sets of package prefixes (and top-level file names), as
 175:    * specifed in INDEX.LIST.
 176:    *
 177:    * @return an map of all the headers, or null if no INDEX.LIST was found
 178:    */
 179:   public LinkedHashMap<URL, Set<String>> getHeaders()
 180:   {
 181:     return prefixes;
 182:   }
 183: }