public Repackager(String repackageSpecs) 
{
        _fromPackages = new ArrayList();
        _toPackages = new ArrayList();
        List repackages = splitPath( repackageSpecs, ';' );
        // Sort the repackage spec so that longer from's are first to match
        // longest package first
        for ( ; ; )
        {
            boolean swapped = false;
            for ( int i = 1 ; i <  repackages.size() ; i++ )
            {
                String spec1 = (String) repackages.get( i - 1 );
                String spec2 = (String) repackages.get( i );
                if (spec1.indexOf( ':' ) <  spec2.indexOf( ':' ))
                {
                    repackages.set( i - 1, spec2 );
                    repackages.set( i, spec1 );
                    swapped = true;
                }
            }
            if (!swapped)
                break;
        }
        for ( int i = 0 ; i <  repackages.size() ; i++ )
        {
            String spec = (String) repackages.get( i );
            int j = spec.indexOf( ':' );
            if (j <  0 || spec.indexOf( ':', j + 1 )  >= 0)
                throw new RuntimeException( "Illegal repackage specification: " + spec );
            String from = spec.substring( 0, j );
            String to = spec.substring( j + 1 );
            _fromPackages.add( Repackager.splitPath( from, '.' ) );
            _toPackages.add( Repackager.splitPath( to, '.' ) );
        }
        _fromMatchers = new Matcher [ _fromPackages.size() * 2 ];
        _toPackageNames = new String [ _fromPackages.size() * 2 ];
        addPatterns( '.', 0 );
        addPatterns( '/', _fromPackages.size() );
}

  void addPatterns(char sep,
    int off) 
{
        for ( int i = 0 ; i <  _fromPackages.size() ; i++ )
        {
            List from = (List) _fromPackages.get( i );
            List to = (List) _toPackages.get( i );
            String pattern = "";
            for ( int j = 0 ; j <  from.size() ; j++ )
            {
                if (j  > 0)
                    pattern += "\\" + sep;
                pattern += from.get( j );
            }
            String toPackage = "";
            for ( int j = 0 ; j <  to.size() ; j++ )
            {
                if (j  > 0)
                    toPackage += sep;
                toPackage += to.get( j );
            }
            _fromMatchers[ off + i ] = Pattern.compile( pattern ).matcher( "" );
            _toPackageNames[ off + i ] = toPackage;
        }
}

 public static String dirForPath(String path) 
{
        return new File(path).getParent();
}

 public List getFromPackages() 
{
        return _fromPackages;
}

 public List getToPackages() 
{
        return _toPackages;
}

 public StringBuffer repackage(StringBuffer sb) 
{
        StringBuffer result = null;
        for ( int i = 0 ; i <  _fromMatchers.length ; i++ )
        {
            Matcher m = (Matcher) _fromMatchers[ i ];
            m.reset( sb );
            for ( boolean found = m.find() ; found ; found = m.find() )
            {
                if (result == null)
                    result = new StringBuffer();
                m.appendReplacement( result, _toPackageNames[ i ] );
            }
            if (result != null)
            {
                m.appendTail( result );
                sb = result;
                result = null;
            }
        }
        return sb;
}

 public static ArrayList splitPath(String path,
    char separator) 
{
        ArrayList components = new ArrayList();
        for ( ; ; )
        {
            int i = path.indexOf( separator );
            if (i <  0)
                break;
            components.add( path.substring( 0, i ) );
            path = path.substring( i + 1 );
        }
        if (path.length()  > 0)
            components.add( path );
        return components;
}