Java Progress Bar remote execution

Question

I am writing an utility in java that connects to the linux machine and executes a linux command and then displays the results. example of the code is below

try
{
 Sch jsch=new JSch();                   
 host=JOptionPane.showInputDialog("Enter username@hostname",       
 System.getProperty("user.name")+"@localhost"); 
 String user=host.substring(0, host.indexOf('@'));
 host=host.substring(host.indexOf('@')+1);
 session=jsch.getSession(user, host, 22);
 UserInfo ui=new MyUserInfo();
 session.setUserInfo(ui);
 session.connect();
 executor = (ChannelExec) session.openChannel("exec"); 
 executor.setCommand(command1);
 executor.connect();
 BufferedReader reader = new BufferedReader(new InputStreamReader  
 (executor.getInputStream())); 
 String line;
 StringBuilder sb = new StringBuilder();
 while((line= reader.readLine()) != null )
 {
   System.out.println(line);

}

    }

    catch (Exception exp){

    }

I have done everything but somehow it only shows the progress bar updates after the code is getting executed. I have also used swing uitilities but it only executes after the code is run...I need some assistance in putting me in correct path Vilas

Answer 1

JavaFx can be used for progress bar with rich UI. I'll give a sample layout example here with progress bar.

Stage myStage=new Stage(); 
GridPane rootNode = new GridPane();
Scene myScene = new Scene(rootNode, 700, 400);

//add a label username and Text field
rootNode.add(new Label("Username:"), 0, 0);
TextField uname = new TextField();
rootNode.add(uname, 1, 0);

//add a button
Button aButton = new Button("Submit");
rootNode.add(aButton, 1, 4);

myStage.setScene(myScene);
myStage.show();

aButton.setOnAction(new EventHandler<ActionEvent>() {
@Override
        public void handle(ActionEvent e) {
          //Do any simple things
          //Dont do complex things in button handle
          runtask();
        }
});

//runtask method
public void runtask(){
     //label for progress bar
     Label updateLabel = new Label("Processing...");
     ProgressBar progress = new ProgressBar();

     VBox updatePane = new VBox();
     updatePane.getChildren().addAll(updateLabel, progress);

     rootNode.add(updatePane,1,6);

     //create a task
     Task<Void> longTask = new Task<Void>() {
        @Override
        protected Void call() throws Exception {

                //do whatever u want
         }
     };
     longTask.setOnSucceeded(new EventHandler<WorkerStateEvent>() {
        @Override
        public void handle(WorkerStateEvent t) {
            //progressbar close when the task completes
            updatePane.setVisible(false);
        }
    });
    progress.progressProperty().bind(longTask.progressProperty());
    updateLabel.textProperty().bind(longTask.messageProperty());

    new Thread(longTask).start();

}

You can use CSS to style and refer https://www.tutorialspoint.com/javafx/javafx_overview.htm for more info. Hope it helps :-)

Answer 2

Please see the code below. I am able to do it using an indeterminate and would like to do it using an progress bar update % wise See the code below

package com.vilas.isstexport;


import java.awt.Container;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.border.EmptyBorder;
import com.jcraft.jsch.ChannelExec;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.JSchException;
import com.jcraft.jsch.Session;
import com.jcraft.jsch.UIKeyboardInteractive;
import com.jcraft.jsch.UserInfo;
import javax.swing.BorderFactory;
import javax.swing.GroupLayout;
import javax.swing.GroupLayout.Alignment;
import javax.swing.JTextField;
import javax.swing.SwingWorker;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.awt.event.ActionEvent;
import javax.swing.JProgressBar;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.border.TitledBorder;
import java.awt.Component;

public class Dataexport extends JFrame {

    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    private JPanel contentPane;
    private JTextField textField;
    private JButton btnExecute = new JButton("Execute");
    private JProgressBar progressBar = new JProgressBar();
    private JScrollPane scrollPane = new JScrollPane();
    private JTextArea textArea = new JTextArea();
    private BackgroundTask backgroundTask;
    private final JLabel statusLabel = new JLabel("Status: ", JLabel.CENTER);


     private final ActionListener buttonActions = new ActionListener() {
            public void actionPerformed(ActionEvent ae) {
                JButton source = (JButton) ae.getSource();
                System.out.println(source.toString());
                if (source == btnExecute) {
                    textArea.setText(null);
                    btnExecute.setEnabled(false);
                    backgroundTask = new BackgroundTask();
                    backgroundTask.execute();
                    progressBar.setIndeterminate(true);
                } 
                /*else if (source == stopButton) {
                    backgroundTask.cancel(true);
                    backgroundTask.done();
                }*/
            }
        };
     private final JLabel lblProgressActivity = new JLabel("Progress Activity");


    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    Dataexport frame = new Dataexport();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    public static class MyUserInfo implements UserInfo, UIKeyboardInteractive{
        public String getPassword(){ return passwd; }
        public boolean promptYesNo(String str){
          Object[] options={ "yes", "no" };
          int optionOutput=JOptionPane.showOptionDialog(null, 
                 str,
                 "Warning", 
                 JOptionPane.DEFAULT_OPTION, 
                 JOptionPane.WARNING_MESSAGE,
                 null, options, options[0]);
           return optionOutput==0;
        }

        String passwd;
        JTextField passwordField=(JTextField)new JPasswordField(20);

        public String getPassphrase(){ return null; }
        public boolean promptPassphrase(String message){ return true; }
        public boolean promptPassword(String message){
          Object[] ob={passwordField}; 
          int result=
            JOptionPane.showConfirmDialog(null, ob, message,
                                          JOptionPane.OK_CANCEL_OPTION);
          if(result==JOptionPane.OK_OPTION){
            passwd=passwordField.getText();
            return true;
          }
          else{ 
            return false; 
          }
        }
        public void showMessage(String message){
          JOptionPane.showMessageDialog(null, message);
        }
        final GridBagConstraints gbc = 
          new GridBagConstraints(0,0,1,1,1,1,
                                 GridBagConstraints.NORTHWEST,
                                 GridBagConstraints.NONE,
                                 new Insets(0,0,0,0),0,0);
        private Container panel;
        public String[] promptKeyboardInteractive(String destination,
                                                  String name,
                                                  String instruction,
                                                  String[] prompt,
                                                  boolean[] echo){
          panel = new JPanel();
          panel.setLayout(new GridBagLayout());

          gbc.weightx = 1.0;
          gbc.gridwidth = GridBagConstraints.REMAINDER;
          gbc.gridx = 0;
          panel.add(new JLabel(instruction), gbc);
          gbc.gridy++;

          gbc.gridwidth = GridBagConstraints.RELATIVE;

          JTextField[] texts=new JTextField[prompt.length];
          for(int i=0; i<prompt.length; i++){
            gbc.fill = GridBagConstraints.NONE;
            gbc.gridx = 0;
            gbc.weightx = 1;
            panel.add(new JLabel(prompt[i]),gbc);

            gbc.gridx = 1;
            gbc.fill = GridBagConstraints.HORIZONTAL;
            gbc.weighty = 1;
            if(echo[i]){
              texts[i]=new JTextField(20);
            }
            else{
              texts[i]=new JPasswordField(20);
            }
            panel.add(texts[i], gbc);
            gbc.gridy++;
          }

          if(JOptionPane.showConfirmDialog(null, panel, 
                                           destination+": "+name,
                                           JOptionPane.OK_CANCEL_OPTION,
                                           JOptionPane.QUESTION_MESSAGE)
             ==JOptionPane.OK_OPTION){
            String[] response=new String[prompt.length];
            for(int i=0; i<prompt.length; i++){
              response[i]=texts[i].getText();
            }
        return response;
          }
          else{
            return null;  // cancel
          }
        }
      }

    private class BackgroundTask extends SwingWorker<Integer, String> {

        private int status;

        public BackgroundTask() {
            System.out.println("state:: "+(this.getState()).toString());
            statusLabel.setText((this.getState()).toString());
        }

        @Override
        protected Integer doInBackground() {

            //String[] command = { "ls -lrt" };
            //String command = "ls -lrt";
            String command = textField.getText().toString();
            ChannelExec  exec = null;

            try {

                  JSch jsch=new JSch(); 
                  String host=null;


                    host=JOptionPane.showInputDialog("Enter username@hostname",
                                                     System.getProperty("user.name")+
                                                     "@localhost"); 

                  String user=host.substring(0, host.indexOf('@'));
                  host=host.substring(host.indexOf('@')+1);

                  Session session=jsch.getSession(user, host, 22);

               // username and password will be given via UserInfo interface.
                  UserInfo ui=new MyUserInfo();
                  session.setUserInfo(ui);
                  session.connect();
                  exec = (ChannelExec) session.openChannel("exec");
                  exec.setCommand(command);
                  exec.setInputStream(null);
                  exec.setErrStream(System.err);

                  exec.connect();


                String s;
                BufferedReader stdout = new BufferedReader(
                    new InputStreamReader(exec.getInputStream()));

                //System.out.println("s:: "+stdout.readLine());

                while ((s = stdout.readLine()) != null && !isCancelled()) {
                    //System.out.println("s:: "+s);
                    publish(s);
                }
                if (!isCancelled()) {
                    status = exec.getExitStatus();
                }
                exec.getInputStream().close();
                exec.getOutputStream().close();
               // exec.getErrorStream().close();
                //p.destroy();
                exec.disconnect();
                session.disconnect();
            } catch (IOException ex) {
                ex.printStackTrace(System.err);
            } catch (JSchException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            return status;
        }

        @Override
        protected void process(java.util.List<String> messages) {

            System.out.println("messages:: "+messages);
            statusLabel.setText((this.getState()).toString());
            for (String message : messages) {
                textArea.append(message + "\n");
            }
        }

        @Override
        protected void done() {
            statusLabel.setText((this.getState()).toString() + " " + status);
            //stopButton.setEnabled(false);
            btnExecute.setEnabled(true);
            progressBar.setIndeterminate(false);
        }

    }




    /**
     * Create the frame.
     */
    public Dataexport() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 761, 497);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);


        JPanel panel = new JPanel();
        panel.setAutoscrolls(true);
        GroupLayout gl_contentPane = new GroupLayout(contentPane);
        gl_contentPane.setHorizontalGroup(
            gl_contentPane.createParallelGroup(Alignment.LEADING)
                .addGroup(gl_contentPane.createSequentialGroup()
                    .addContainerGap()
                    .addComponent(panel, GroupLayout.DEFAULT_SIZE, 739, Short.MAX_VALUE))
        );
        gl_contentPane.setVerticalGroup(
            gl_contentPane.createParallelGroup(Alignment.LEADING)
                .addGroup(Alignment.TRAILING, gl_contentPane.createSequentialGroup()
                    .addContainerGap(44, Short.MAX_VALUE)
                    .addComponent(panel, GroupLayout.PREFERRED_SIZE, 431, GroupLayout.PREFERRED_SIZE)
                    .addContainerGap())
        );
        panel.setLayout(null);

        textField = new JTextField();
        textField.setBounds(232, 12, 114, 19);
        textField.setColumns(10);
        panel.add(textField);


        btnExecute.setBounds(232, 95, 114, 25);
        panel.add(btnExecute);
        btnExecute.addActionListener(buttonActions);





        progressBar.setEnabled(false);
        progressBar.setBounds(232, 51, 370, 14);
        panel.add(progressBar);
        scrollPane.setAlignmentY(Component.BOTTOM_ALIGNMENT);
        scrollPane.setAlignmentX(Component.RIGHT_ALIGNMENT);
        scrollPane.setViewportBorder(new TitledBorder(null, "", TitledBorder.LEADING, TitledBorder.TOP, null, null));

        scrollPane.setBounds(33, 163, 680, 240);
        panel.add(scrollPane);
        scrollPane.setBorder(BorderFactory.createTitledBorder("Output: "));
        scrollPane.setViewportView(textArea);

        JLabel lblEnterTheCommand = new JLabel("Enter the Command");
        lblEnterTheCommand.setBounds(33, 14, 152, 15);
        panel.add(lblEnterTheCommand);
        lblProgressActivity.setBounds(33, 51, 152, 15);

        panel.add(lblProgressActivity);
        contentPane.setLayout(gl_contentPane);
    }
}