code: private boolean openTagSet(String filename)
      {
          int max_size = 0;
          InputStreamReader isr = null;
          y_.clear();
          try
          {
              isr = new InputStreamReader(IOUtil.newInputStream(filename), "UTF-8");
              BufferedReader br = new BufferedReader(isr);
              String line;
              while ((line = br.readLine()) != null)
              {
                  if (line.length() == 0)
                  {
                      continue;
                  }
                  char firstChar = line.charAt(0);
                  if (firstChar == '\0' || firstChar == ' ' || firstChar == '\t')
                  {
                      continue;
                  }
                  String[] cols = line.split("[\t ]", -1);
                  if (max_size == 0)
                  {
                      max_size = cols.length;
                  }
                  if (max_size != cols.length)
                  {
                      String msg = "inconsistent column size: " + max_size +
                          " " + cols.length + " " + filename;
                      throw new RuntimeException(msg);
                  }
                  xsize_ = cols.length - 1;
                  if (y_.indexOf(cols[max_size - 1]) == -1)
                  {
                      y_.add(cols[max_size - 1]);
                  }
              }
              Collections.sort(y_);
              br.close();
          }
          catch (Exception e)
          {
              if (isr != null)
              {
                  try
                  {
                      isr.close();
                  }
                  catch (Exception e2)
                  {
                  }
              }
              e.printStackTrace();
              System.err.println("Error reading " + filename);
              return false;
          }
          return true;
      }
docs: 读取训练文件中的标注集
  
  @param filename
  @return