public int[] getGlyphIdToCharacterCode() 
{
        return glyphIdToCharacterCode;
}

 public int getPlatformEncodingId() 
{
        return platformEncodingId;
}

 public int getPlatformId() 
{
        return platformId;
}

 public  void initData(TrueTypeFont ttf,
    TTFDataStream data) throws IOException 
{
        platformId = data.readUnsignedShort();
        platformEncodingId = data.readUnsignedShort();
        subTableOffset = data.readUnsignedInt();
}

This will read the required data from the stream.

 public  void initSubtable(TrueTypeFont ttf,
    TTFDataStream data) throws IOException 
{
        data.seek( ttf.getCMAP().getOffset() + subTableOffset );
        int subtableFormat = data.readUnsignedShort();
        int length = data.readUnsignedShort();
        int version = data.readUnsignedShort();
        int numGlyphs = ttf.getMaximumProfile().getNumGlyphs();
        if( subtableFormat == 0 )
        {
            byte[] glyphMapping = data.read( 256 );
            glyphIdToCharacterCode = new int[256];
            for( int i=0;i< glyphMapping.length; i++ )
            {
                glyphIdToCharacterCode[i]=(glyphMapping[i]+256)%256;
            }
        }
        else if( subtableFormat == 2 )
        {
            int[] subHeaderKeys = new int[256];
            for( int i=0; i< 256; i++)
            {
                subHeaderKeys[i] = data.readUnsignedShort();
            }
            int firstCode = data.readUnsignedShort();
            int entryCount = data.readUnsignedShort();
            short idDelta = data.readSignedShort();
            int idRangeOffset = data.readUnsignedShort();
            //BJL
            //HMM the TTF spec is not very clear about what is suppose to
            //happen here.  If you know please submit a patch or point
            //me to some better documentation.
            throw new IOException( "Not yet implemented:" + subtableFormat );
        }
        else if( subtableFormat == 4 )
        {
            int segCountX2 = data.readUnsignedShort();
            int segCount = segCountX2/2;
            int searchRange = data.readUnsignedShort();
            int entrySelector = data.readUnsignedShort();
            int rangeShift = data.readUnsignedShort();
            int[] endCount = data.readUnsignedShortArray( segCount );
            int reservedPad = data.readUnsignedShort();
            int[] startCount = data.readUnsignedShortArray( segCount );
            int[] idDelta = data.readUnsignedShortArray( segCount );
            int[] idRangeOffset = data.readUnsignedShortArray( segCount );
            //this is the final result
            //key=glyphId, value is character codes
            glyphIdToCharacterCode = new int[numGlyphs];
            long currentPosition = data.getCurrentPosition();
            for( int i=0; i< segCount; i++ )
            {
                int start = startCount[i];
                int end = endCount[i];
                int delta = idDelta[i];
                int rangeOffset = idRangeOffset[i];
                if( start != 65535 && end != 65535 )
                {
                    for( int j=start; j< =end; j++ )
                    {
                        if( rangeOffset == 0 )
                        {
                            glyphIdToCharacterCode[ ((j+delta)%65536) ]=j;
                        }
                        else
                        {
                            long glyphOffset = currentPosition +
                                ((rangeOffset/2) + //idRangeOffset[i]/2 
                                (j-start) + //(c - startCount[i])                                   
                                (i-segCount))*2; //&idRangeOffset[i]); 
                            data.seek( glyphOffset );
                            int glyphIndex = data.readUnsignedShort();
                            if( glyphIndex != 0 )
                            {
                                glyphIndex += delta;
                                glyphIndex = glyphIndex % 65536;
                                if( glyphIdToCharacterCode[glyphIndex] == 0 )
                                {
                                    glyphIdToCharacterCode[glyphIndex] = j;
                                }
                            }
                        }
                    }
                }
            }
        }
        else if( subtableFormat == 6 )
        {
            int firstCode = data.readUnsignedShort();
            int entryCount = data.readUnsignedShort();
            glyphIdToCharacterCode = new int[numGlyphs];
            int[] glyphIdArray = data.readUnsignedShortArray( entryCount );
            for( int i=0; i< entryCount; i++)
            {
                glyphIdToCharacterCode[glyphIdArray[i]] = firstCode+i;
            }
        }
        else
        {
            throw new IOException( "Unknown cmap format:" + subtableFormat );
        }
}

This will read the required data from the stream.

 public  void setGlyphIdToCharacterCode(int[] glyphIdToCharacterCodeValue) 
{
        this.glyphIdToCharacterCode = glyphIdToCharacterCodeValue;
}

 public  void setPlatformEncodingId(int platformEncodingIdValue) 
{
        this.platformEncodingId = platformEncodingIdValue;
}

 public  void setPlatformId(int platformIdValue) 
{
        this.platformId = platformIdValue;
}