code: package swing.common;
  
  import org.apache.tika.Tika;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.swing.*;
  import javax.swing.table.JTableHeader;
  import javax.swing.table.TableColumn;
  import java.awt.*;
  import java.io.*;
  import java.util.Enumeration;
  
  /**
   * Created by yzhang29 on 23/11/17.
   */
  public class SwingUtils {
      protected static final Logger logger = LoggerFactory.getLogger(SwingUtils.class);
      private final static String PCAP = "application/vnd.tcpdump.pcap";
      public static void fitTableColumns(JTable myTable) {
          JTableHeader header = myTable.getTableHeader();
          int rowCount = myTable.getRowCount();
  
          Enumeration columns = myTable.getColumnModel().getColumns();
          while (columns.hasMoreElements()) {
              TableColumn column = (TableColumn) columns.nextElement();
              int col = header.getColumnModel().getColumnIndex(column.getIdentifier());
              int width = (int) myTable.getTableHeader().getDefaultRenderer()
                      .getTableCellRendererComponent(myTable, column.getIdentifier(), false, false, -1, col)
                      .getPreferredSize().getWidth();
              for (int row = 0; row < rowCount; row++) {
                  int preferedWidth = (int) myTable.getCellRenderer(row, col)
                          .getTableCellRendererComponent(myTable, myTable.getValueAt(row, col), false, false, row, col)
                          .getPreferredSize().getWidth();
                  width = Math.max(width, preferedWidth);
              }
              header.setResizingColumn(column);
              column.setWidth(width + myTable.getIntercellSpacing().width + 10);
          }
      }
  
      public static void setBorderLayoutPane(Container container, Component comp, Object constraints){
  
          if (container == null) {
              throw new IllegalArgumentException("BorderLayoutPane cannot be null!!");
          }
  
          BorderLayout layout = (BorderLayout) container.getLayout();
          Component oldComp = layout.getLayoutComponent(constraints);
  
          if(oldComp==null) {
              if(comp!=null) {
                  container.add(comp,constraints);
              }
              container.repaint();
              container.revalidate();
          }else {
              if(comp!=oldComp) {
                  container.remove(oldComp);
                  if(comp!=null) {
                      container.add(comp,constraints);
                  }
                  container.repaint();
                  container.revalidate();
              }
          }
      }
  
      public static boolean isPcapFile(File file) {
  
          if (file == null) {
              return false;
          }
  
          try {
  
              String contentType;
  
              //Files.probeContentType returns null on Windows
              /*Path filePath = Paths.get(file.getPath());
              contentType = Files.probeContentType(filePath);*/
  
              contentType = new Tika().detect(file);
  
              if (PCAP.equalsIgnoreCase(contentType)) {
                  return true;
              }else{
                  return false;
              }
  
          } catch (IOException e) {
              logger.debug(e.getMessage());
          }
  
          return false;
      }
  
      public static long countLines(String fileName) {
          File file =new File(fileName);
          int linenumber = 0;
          FileReader fr;
          LineNumberReader lnr = null;
          try {
              fr = new FileReader(file);
              lnr = new LineNumberReader(fr);
  
              while (lnr.readLine() != null){
                  linenumber++;
              }
  
          } catch (IOException e) {
              logger.debug(e.getMessage());
          } finally {
  
              if (lnr != null) {
  
                  try {
                      lnr.close();
                  } catch (IOException e) {
                      logger.debug(e.getMessage());
                  }
              }
          }
          return linenumber;
      }
  }
  