code: public Vector query(String content)
      {
          if (content == null || content.length() == 0) return null;
          List<Term> termList = NotionalTokenizer.segment(content);
          Vector result = new Vector(dimension());
          int n = 0;
          for (Term term : termList)
          {
              Vector vector = wordVectorModel.vector(term.word);
              if (vector == null)
              {
                  continue;
              }
              ++n;
              result.addToSelf(vector);
          }
          if (n == 0)
          {
              return null;
          }
          result.normalize();
          return result;
      }
docs: 将一个文档转为向量
  
  @param content 文档
  @return 向量