code: public static void borderTable(XWPFTable table, int size) {
          CTTblPr tblPr = getTblPr(table);
          CTTblBorders tblBorders = tblPr.getTblBorders();
          BigInteger borderSize = BigInteger.valueOf(size);
          tblBorders.getBottom().setSz(borderSize);
          tblBorders.getLeft().setSz(borderSize);
          tblBorders.getTop().setSz(borderSize);
          tblBorders.getRight().setSz(borderSize);
          tblBorders.getInsideH().setSz(borderSize);
          tblBorders.getInsideV().setSz(borderSize);
      }
docs: 设置表格边框
  
  @param table
  @param size