mirror of git://gcc.gnu.org/git/gcc.git
				
				
				
			
		
			
				
	
	
		
			264 lines
		
	
	
		
			9.6 KiB
		
	
	
	
		
			Java
		
	
	
	
			
		
		
	
	
			264 lines
		
	
	
		
			9.6 KiB
		
	
	
	
		
			Java
		
	
	
	
| /* Resolver.java --
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|    Copyright (C) 1999,2000,2001 Free Software Foundation, Inc.
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| 
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| This file is part of GNU Classpath.
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| 
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| GNU Classpath is free software; you can redistribute it and/or modify
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| it under the terms of the GNU General Public License as published by
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| the Free Software Foundation; either version 2, or (at your option)
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| any later version.
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| 
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| GNU Classpath is distributed in the hope that it will be useful, but
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| WITHOUT ANY WARRANTY; without even the implied warranty of
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| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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| General Public License for more details.
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| 
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| You should have received a copy of the GNU General Public License
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| along with GNU Classpath; see the file COPYING.  If not, write to the
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| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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| 02110-1301 USA.
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| 
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| Linking this library statically or dynamically with other modules is
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| making a combined work based on this library.  Thus, the terms and
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| conditions of the GNU General Public License cover the whole
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| combination.
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| 
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| As a special exception, the copyright holders of this library give you
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| permission to link this library with independent modules to produce an
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| executable, regardless of the license terms of these independent
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| modules, and to copy and distribute the resulting executable under
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| terms of your choice, provided that you also meet, for each linked
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| independent module, the terms and conditions of the license of that
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| module.  An independent module is a module which is not derived from
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| or based on this library.  If you modify this library, you may extend
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| this exception to your version of the library, but you are not
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| obligated to do so.  If you do not wish to do so, delete this
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| exception statement from your version. */
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| 
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| package gnu.xml.util;
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| 
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| import java.io.File;
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| import java.io.IOException;
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| import java.util.Dictionary;
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| 
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| import org.xml.sax.EntityResolver;
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| import org.xml.sax.InputSource;
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| import org.xml.sax.SAXException;
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| 
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| /**
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|  * Utility implementation of a SAX resolver, which can be used to improve
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|  * network utilization of SAX based XML components.  It does this by
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|  * supporting local caches of external entities.
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|  * SAX parsers <em>should</em> use such local caches when possible.
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|  *
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|  * @see XCat
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|  */
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| public class Resolver implements EntityResolver, Cloneable
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| {
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|     /**
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|      * Updates a dictionary used to map PUBLIC identifiers to file names,
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|      * so that it uses the mappings in a specified directory.
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|      *
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|      * @param mappings Array of string pairs, where the first member
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|      *  of each pair is a PUBLIC identifier and the second is the
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|      *  name of a file, relative to the specified directory.
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|      * @param directory File holding the specified files.
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|      */
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|     public static void addDirectoryMapping (
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|         Dictionary      table,
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|         String          mappings [][],
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|         File            directory
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|     ) throws IOException
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|     {
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|         for (int i = 0; i < mappings.length; i++) {
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|             File        file = new File (directory, mappings [i][1]);
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|             String      temp;
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| 
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|             if (!file.exists ())        // ?? log a warning ??
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|                 continue;
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| 
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|             temp = fileToURL (file);
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|             table.put (mappings [i][0], temp);
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|         }
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|     }
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| 
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|         // FIXME: these *URL routines don't quite belong here, except
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|         // that they're all in the same spirit of making it easy to
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|         // use local filesystem URIs with XML parsers.
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| 
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|     /**
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|      * Provides the URL for a named file, without relying on the JDK 1.2
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|      * {@link java.io.File#toURL File.toURL}() utility method.
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|      *
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|      * @param filename the file name to convert.  Relative file names
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|      *  are resolved the way the JVM resolves them (current to the
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|      *  process-global current working directory).
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|      *
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|      * @exception IOException if the file does not exist
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|      */
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|     public static String fileNameToURL (String filename)
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|     throws IOException
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|     {
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|         return fileToURL (new File (filename));
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|     }
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| 
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|     /**
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|      * Provides the URL for a file, without relying on the JDK 1.2
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|      * {@link java.io.File#toURL File.toURL}() utility method.
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|      *
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|      * @param f the file to convert.  Relative file names
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|      *  are resolved the way the JVM resolves them (current to the
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|      *  process-global current working directory).
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|      *
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|      * @exception IOException if the file does not exist
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|      */
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|     public static String fileToURL (File f)
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|     throws IOException
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|     {
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|         String  temp;
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| 
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|         // NOTE:  the javax.xml.parsers.DocumentBuilder and
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|         // javax.xml.transform.stream.StreamSource versions
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|         // of this don't have this test.  Some JVM versions
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|         // don't report this error sanely through URL code.
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|         if (!f.exists ())
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|             throw new IOException ("no such file: " + f.getName ());
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| 
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|             // FIXME: getAbsolutePath() seems buggy; I'm seeing components
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|             // like "/foo/../" which are clearly not "absolute"
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|             // and should have been resolved with the filesystem.
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| 
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|             // Substituting "/" would be wrong, "foo" may have been
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|             // symlinked ... the URL code will make that change
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|             // later, so that things can get _really_ broken!
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| 
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|         temp = f.getAbsolutePath ();
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| 
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|         if (File.separatorChar != '/')
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|             temp = temp.replace (File.separatorChar, '/');
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|         if (!temp.startsWith ("/"))
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|             temp = "/" + temp;
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|         if (!temp.endsWith ("/") && f.isDirectory ())
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|             temp = temp + "/";
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|         return "file:" + temp;
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|     }
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| 
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| 
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|     /**
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|      * Returns a URL string.  Note that if a malformed URL is provided, or
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|      * the parameter names a nonexistent file, the resulting URL may be
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|      * malformed.
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|      *
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|      * @param fileOrURL If this is the name of a file which exists,
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|      *  then its URL is returned.  Otherwise the argument is returned.
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|      */
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|     public static String getURL (String fileOrURL)
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|     {
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|         try {
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|             return fileNameToURL (fileOrURL);
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|         } catch (Exception e) {
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|             return fileOrURL;
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|         }
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|     }
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| 
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| 
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| 
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|     // note:  cloneable, this is just copied; unguarded against mods
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|     private Dictionary          pubidMapping;
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| 
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|     /**
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|      * Constructs a resolver which understands how to map PUBLIC identifiers
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|      * to other URIs, typically for local copies of standard DTD components.
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|      *
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|      * @param dict maps PUBLIC identifiers to URIs.  This is not
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|      *  copied; subsequent modifications will be reported through the
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|      *  resolution operations.
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|      */
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|     public Resolver (Dictionary dict)
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|         { pubidMapping = dict; }
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| 
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| 
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|     // FIXME: want notion of a "system default" resolver, presumably
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|     // loaded with all sorts of useful stuff.  At the same time need
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|     // a notion of resolver chaining (failure --> next) so that subsystems
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|     // can set up things that won't interfere with other ones.
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| 
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|     /**
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|      * This parses most MIME content type strings that have <em>charset=...</em>
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|      * encoding declarations to and returns the specified encoding.  This
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|      * conforms to RFC 3023, and is useful when constructing InputSource
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|      * objects from URLConnection objects or other objects using MIME
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|      * content typing.
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|      *
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|      * @param contentType the MIME content type that will be parsed; must
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|      *  not be null.
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|      * @return the appropriate encoding, or null if the content type is
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|      *  not text and there's no <code>charset=...</code> attribute
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|      */
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|     static public String getEncoding (String contentType)
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|     {
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|         // currently a dumb parsing algorithm that works "mostly" and handles
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|         //      ..anything...charset=ABC
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|         //      ..anything...charset=ABC;otherAttr=DEF
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|         //      ..anything...charset=ABC (comment);otherAttr=DEF
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|         //      ..anything...charset= "ABC" (comment);otherAttr=DEF
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| 
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|         int     temp;
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|         String  encoding;
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|         String  defValue = null;
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| 
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|         if (contentType.startsWith ("text/"))
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|             defValue = contentType.startsWith ("text/html")
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|                     ? "ISO-8859-1" : "US-ASCII";
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| 
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|         // Assumes 'charset' is only an attribute name, not part
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|         // of a value, comment, or other attribute name
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|         // ALSO assumes no escaped values like "\;" or "\)"
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|         if ((temp = contentType.indexOf ("charset")) != -1) {
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|             // strip out everything up to '=' ...
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|             temp = contentType.indexOf ('=', temp);
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|             if (temp == -1)
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|                 return defValue;
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|             encoding = contentType.substring (temp + 1);
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|             // ... and any subsequent attributes
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|             if ((temp = encoding.indexOf (';')) != -1)
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|                 encoding = encoding.substring (0, temp);
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|             // ... and any comments after value
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|             if ((temp = encoding.indexOf ('(')) != -1)
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|                 encoding = encoding.substring (0, temp);
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|             // ... then whitespace, and any (double) quotes
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|             encoding = encoding.trim ();
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|             if (encoding.charAt (0) == '"')
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|                 encoding = encoding.substring (1, encoding.length () - 1);
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|         } else
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|             encoding = defValue;
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|         return encoding;
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|     }
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| 
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| 
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|     /**
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|      * Uses a local dictionary of public identifiers to resolve URIs,
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|      * normally with the goal of minimizing network traffic or latencies.
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|      */
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|     public InputSource resolveEntity (String publicId, String systemId)
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|     throws IOException, SAXException
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|     {
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|         InputSource     retval = null;
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|         String          uri;
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| 
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|         if (publicId != null
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|                 && ((uri = (String) pubidMapping.get (publicId)) != null)) {
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|             retval = new InputSource (uri);
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|             retval.setPublicId (publicId);
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|         }
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| 
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|         // Could do URN resolution here
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| 
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|         // URL resolution always done by parser
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| 
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|         // FIXME: chain to "next" resolver
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| 
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|         return retval;
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|     }
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| }
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