code: public ConsoleLog getConsoleOutputText(int bufferOffset, boolean crumbFlag) throws IOException {
          List<NameValuePair> formData = new ArrayList<>();
          formData.add(new BasicNameValuePair("start", Integer.toString(bufferOffset)));
          String path = getUrl() + "logText/progressiveText";
          HttpResponse httpResponse = client.post_form_with_result(path, formData, crumbFlag);
  
          Header moreDataHeader = httpResponse.getFirstHeader(MORE_DATA_HEADER);
          Header textSizeHeader = httpResponse.getFirstHeader(TEXT_SIZE_HEADER);
          String response = EntityUtils.toString(httpResponse.getEntity());
          boolean hasMoreData = false;
          if (moreDataHeader != null) {
              hasMoreData = Boolean.TRUE.toString().equals(moreDataHeader.getValue());
          }
          Integer currentBufferSize = bufferOffset;
          if (textSizeHeader != null) {
              try {
                  currentBufferSize = Integer.parseInt(textSizeHeader.getValue());
              } catch (NumberFormatException e) {
                  LOGGER.warn("Cannot parse buffer size for job {0} build {1}. Using current offset!", this.getDisplayName(), this.getNumber());
              }
          }
          return new ConsoleLog(response, hasMoreData, currentBufferSize);
      }
docs: Get build console output log as text.
  Use this method to periodically obtain logs from jenkins and skip chunks that were already received
  
  @param bufferOffset offset in console lo
  @param crumbFlag <code>true</code> or <code>false</code>.
  @return ConsoleLog object containing console output of the build. The line separation is done by
  {@code CR+LF}.
  @throws IOException in case of a failure.