code: public void readSource(String input) throws GraphVizException
  	{
  		StringBuilder sb = new StringBuilder();
  		try
  		{
  			FileInputStream fis = new FileInputStream(input);
  			DataInputStream dis = new DataInputStream(fis);
  			BufferedReader br = new BufferedReader(new InputStreamReader(dis));
  			String line;
  			while ((line = br.readLine()) != null)
  			{
  				sb.append(line);
  			}
  			dis.close();
  		} catch (Exception e)
  		{
  			throw new GraphVizException("Error: " + e.getMessage());
  		}
  		this.graph = sb;
  	}
docs: Read a DOT graph from a text file.
  
  @param input
  Input text file containing the DOT graph source.
  @throws GraphVizException