code: public String buildSelectExplorerFileEntries(String htmlAttributes) {
  
          String emptyOption = OpenCms.getWorkplaceManager().getDefaultUserSettings().getExplorerFileEntryOptions();
          if (CmsStringUtil.isEmptyOrWhitespaceOnly(emptyOption)) {
              emptyOption = "50,100,200,300,400,500";
          }
          // remove all non digits without ','
          emptyOption = emptyOption.replaceAll("[^0-9|^,]", "");
          // remove all empty entries
          emptyOption = emptyOption.replaceAll(",,", ",");
          List<String> opts = CmsStringUtil.splitAsList(emptyOption, ",", true);
          opts.add(key(Messages.GUI_LABEL_UNLIMITED_0));
          opts.remove("0");
          List<String> vals = CmsStringUtil.splitAsList(emptyOption, ",", true);
          vals.add("" + Integer.MAX_VALUE);
          vals.remove("0");
          int selectedIndex = 2;
          for (int i = 0; i < vals.size(); i++) {
              if (vals.get(i).equals(getParamTabExFileEntries())) {
                  selectedIndex = i;
                  break;
              }
          }
          return buildSelect(htmlAttributes, opts, vals, selectedIndex);
      }
docs: Builds the html for the explorer number of entries per page select box.<p>
  
  @param htmlAttributes optional html attributes for the &lgt;select&gt; tag
  @return the html for the explorer number of entries per page select box