aw080/main/ooxml/source/framework/SchemaParser/src/org/apache/openoffice/ooxml/schema/model/schema/NamespaceMap.java

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package org.apache.openoffice.ooxml.schema.model.schema;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.TreeMap;

/** Map between namespace prefixes and URIs.
 *  While namespace URIs can have different prefixes in different schemas,
 *  we will use only one prefix in the OOXML parser.  This class
 *  provides these global prefixes. 
 */
public class NamespaceMap
    implements Iterable<Entry<String, String>>
{
    public NamespaceMap ()
    {
        maURIToPrefixMap = new HashMap<>(maPredefinedURIToPrefixMap);
        
        // Predefine namespace prefixes.
        // If possible then use the ones already in use in the schema files or documents written by MS Office,
        // appended with a 06 or 12 for the ECMA-376 standards of 2006 (1st edition) or 2012 (4th edition). 
        maURIToPrefixMap.put("http://schemas.openxmlformats.org/drawingml/2006/main", "a06");
        maURIToPrefixMap.put("http://purl.oclc.org/ooxml/drawingml/main", "a12");

        maURIToPrefixMap.put("http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing", "wp06");
        maURIToPrefixMap.put("http://purl.oclc.org/ooxml/drawingml/wordprocessingDrawing", "wp12");

        maURIToPrefixMap.put("http://schemas.openxmlformats.org/wordprocessingml/2006/main", "w06");
        maURIToPrefixMap.put("http://purl.oclc.org/ooxml/wordprocessingml/main", "w12");

        maURIToPrefixMap.put("http://schemas.openxmlformats.org/drawingml/2006/picture", "dpct06");
        maURIToPrefixMap.put("http://purl.oclc.org/ooxml/drawingml/picture", "dpct12");
        
        maURIToPrefixMap.put("http://schemas.openxmlformats.org/officeDocument/2006/math", "m06");
        maURIToPrefixMap.put("http://purl.oclc.org/ooxml/officeDocument/math", "m12");
        
        maURIToPrefixMap.put("http://schemas.openxmlformats.org/officeDocument/2006/relationships", "r06");
        maURIToPrefixMap.put("http://purl.oclc.org/ooxml/officeDocument/relationships", "r12");
        
        // Invent prefixes that are not in use.
        maURIToPrefixMap.put("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "s06");
        maURIToPrefixMap.put("http://purl.oclc.org/ooxml/spreadsheetml/main", "s12");
        
        maURIToPrefixMap.put("http://schemas.openxmlformats.org/presentationml/2006/main", "p06");
        maURIToPrefixMap.put("http://purl.oclc.org/ooxml/presentationml/main", "p12");
        
        maURIToPrefixMap.put("http://schemas.openxmlformats.org/schemaLibrary/2006/main", "sl06");
        maURIToPrefixMap.put("http://purl.oclc.org/ooxml/schemaLibrary/main", "sl12");

        maURIToPrefixMap.put("http://purl.oclc.org/ooxml/drawingml/diagram", "dd12");
        maURIToPrefixMap.put("http://purl.oclc.org/ooxml/drawingml/chart", "dc12");
        maURIToPrefixMap.put("http://purl.oclc.org/ooxml/drawingml/lockedCanvas", "dlc12");
    }
    
    
    
    
    public void ProvideNamespace (
        final String sNamespaceURI,
        final String sDefaultPrefix)
    {
        if ( ! maURIToPrefixMap.containsKey(sNamespaceURI))
        {
            final String sPrefix;
            // Check if we can use the given prefix.
            if (sDefaultPrefix==null || IsPrefixUsed(sDefaultPrefix))
            {
            	// Prefix is already used.  We have to create a new and unique one.
            	String sCandidate = null;
            	for (int nIndex=0; nIndex<=26; ++nIndex)
            	{
            		if (nIndex == 26)
            			throw new RuntimeException("can not invent more than 26 namespace names");
            		sCandidate= new String(new byte[]{(byte)('A'+nIndex)});
            		if ( ! maURIToPrefixMap.containsKey(sCandidate))
            			break;
            	}
            	sPrefix = sCandidate;
            }
            else
            {
            	// Use the given prefix.
            	sPrefix = sDefaultPrefix;
            }

            maURIToPrefixMap.put(sNamespaceURI, sPrefix);
        }
    }
    
    
    
    
    public String GetNamespacePrefix (final String sURI)
    {
        return maURIToPrefixMap.get(sURI);
    }
    
    
    
    
    public Iterator<Entry<String,String>> iterator ()
    {
        return maURIToPrefixMap.entrySet().iterator();
    }
    
    
    
    
    public Object GetCount()
    {
        return maURIToPrefixMap.size();
    }

    
    
    
    /** Return all namespace entries sorted on the prefix.
     */
    public Iterable<Entry<String,String>> GetSorted ()
    {
    	final Map<String,Entry<String,String>> aSortedEntries = new TreeMap<>();
    	for (final Entry<String,String> aEntry : maURIToPrefixMap.entrySet())
    		if (aEntry.getValue() == null)
        		aSortedEntries.put("", aEntry);
    		else
    			aSortedEntries.put(aEntry.getValue(), aEntry);
    	return aSortedEntries.values();
    }
    
    
    
    
    private boolean IsPrefixUsed (final String sPrefix)
    {
        for (final String sUsedPrefix : maURIToPrefixMap.values())
        {
            if (sUsedPrefix == null)
                continue;
            if (sUsedPrefix.equals(sPrefix))
                return true;
        }
        return false;
    }
    
    
    
    
    private final Map<String,String> maURIToPrefixMap;
    private final static Map<String,String> maPredefinedURIToPrefixMap;
    static
    {
        maPredefinedURIToPrefixMap =  new HashMap<>();
        maPredefinedURIToPrefixMap.put("http://www.w3.org/2001/XMLSchema", "xsd");
    }
}