ProgressMonitorInputStream creates an instance of ProgressMonitor (last example). The progress of reading an input stream is automatically shown when necessary.

Example

public class ProgressMonitorInputStreamExample {

  public static void main(String[] args) throws IOException {
      JFrame frame = createFrame("ProgressMonitorInputStream Example");
      JButton button = new JButton("read file");
      button.addActionListener(createReadFileListener(frame));
      button.setEnabled(true);

      frame.add(button, BorderLayout.NORTH);
      frame.setVisible(true);
  }

  private static ActionListener createReadFileListener(Component parent) throws IOException {
      File file = createTestFile();
      file.deleteOnExit();
      //for progress dialog title
      UIManager.put("ProgressMonitor.progressText", "Reading a test file");
      return (ae) -> {
          new Thread(() -> {
              ProgressMonitorInputStream pMonitorInputStream;
              try (BufferedInputStream bis = new BufferedInputStream(
                      pMonitorInputStream = new ProgressMonitorInputStream(
                              parent,
                              "Reading " + file.getName(),
                              new FileInputStream(file)))) {
                  ProgressMonitor progressMonitor = pMonitorInputStream.getProgressMonitor();
                  progressMonitor.setMillisToDecideToPopup(100);
                  progressMonitor.setMillisToPopup(100);

                  byte[] buffer = new byte[2048];
                  while ((bis.read(buffer)) != -1) {
                      System.out.println(new String(buffer));
                      progressMonitor.setNote(bis.available()/1000+ " more kb to read.");
                      //simulating some processing delay
                      Thread.sleep(2);
                  }
              } catch (Exception e) {
                  throw new RuntimeException(e);
              }
          }).start();
      };
  }

  private static File createTestFile() throws IOException {
      Path testPath = Files.createTempFile("test", ".txt");
      String textData = IntStream.range(1, 1000000)
                                 .mapToObj(Integer::toString)
                                 .collect(Collectors.joining());
      Files.write(testPath, textData.getBytes());
      return testPath.toFile();
  }

  public static JFrame createFrame(String title) {
      JFrame frame = new JFrame(title);
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.setSize(new Dimension(800, 700));
      return frame;
  }
}

Output

On clicking 'read file' button:

Example Project

Dependencies and Technologies Used:

• JDK 10
• Maven 3.3.9