Command line progress bar in Java

Question

I have a Java program running in command line mode. I would like to display a progress bar, showing the percentage of job done. The same kind of progress bar you would see using wget under unix. Is this possible?

Answer 1

I have recently faced the same problem, you can check my code: I have set it for one # on 5%, which you can modify later.

public static void main (String[] args) throws java.lang.Exception
{
    int i = 0;
    while(i < 21) {
        System.out.print("[");
        for (int j=0;j<i;j++) {
            System.out.print("#");
        }

        for (int j=0;j<20-i;j++) {
            System.out.print(" ");
        }

        System.out.print("] "+  i*5 + "%");
        if(i<20) {
            System.out.print("\r");
            Thread.sleep(300);
        }
        i++;
    }
    System.out.println();
}

Answer 2

public static void main(String[] argv) throws Exception{


    System.out.write("\r".getBytes());
    int percentage =10;
    while(percentage <= 100) {
        String temp =generateStars(percentage);
        System.out.write(temp.getBytes());
        System.out.print("\b\b\b");
        percentage = percentage+10;
        Thread.sleep(500);
    }
}

    public static String generateStars(int percentage)
    {
        int startsNum = percentage / 4;
        StringBuilder builder = new StringBuilder();
        while(startsNum >= 0)
        {
        builder.append("*");
        startsNum--;
        }
        builder.append(percentage+"%");
        return builder.toString();
    }

Answer 3

C# Example but I'm assuming this is the same for System.out.print in Java. Feel free to correct me if I'm wrong.

Basically, you want to write out the \r escape character to the start of your message which will cause the cursor to return to the start of the line (Line Feed) without moving to the next line.

    static string DisplayBar(int i)
    {
        StringBuilder sb = new StringBuilder();

        int x = i / 2;
        sb.Append("|");
        for (int k = 0; k < 50; k++)
            sb.AppendFormat("{0}", ((x <= k) ? " " : "="));
        sb.Append("|");

        return sb.ToString();
    }

    static void Main(string[] args)
    {
        for (int i = 0; i <= 100; i++)
        {
            System.Threading.Thread.Sleep(200);
            Console.Write("\r{0} {1}% Done", DisplayBar(i), i);
        }

        Console.ReadLine();

    }

Answer 4

public class ProgressBar
{
    private int max;

    public ProgressBar(int max0) {
        max = max0;
        update(0);
    }

    public void update(int perc) {
        String toPrint = "|";
        for(int i = 0; i < max; i++) {
            if(i <= (perc + 1))
                toPrint += "=";
            else
                toPrint += " ";
        }

        if(perc >= max)
            Console.print("\r");
        else
            Console.print(toPrint + "|\r");
    }
}

Answer 5

There is https://github.com/ctongfei/progressbar, License: MIT

Simple console progress bar. Progress bar writing now runs on another thread.

Menlo, Fira Mono, Source Code Pro or SF Mono are recommended for optimal visual effects.

For Consolas or Andale Mono fonts, use ProgressBarStyle.ASCII (see below) because the box-drawing glyphs are not aligned properly in these fonts.

Maven:

<dependency>
  <groupId>me.tongfei</groupId>
  <artifactId>progressbar</artifactId>
  <version>0.5.5</version>
</dependency>

Usage:

ProgressBar pb = new ProgressBar("Test", 100); // name, initial max
 // Use ProgressBar("Test", 100, ProgressBarStyle.ASCII) if you want ASCII output style
pb.start(); // the progress bar starts timing
// Or you could combine these two lines like this:
//   ProgressBar pb = new ProgressBar("Test", 100).start();
some loop {
  ...
  pb.step(); // step by 1
  pb.stepBy(n); // step by n
  ...
  pb.stepTo(n); // step directly to n
  ...
  pb.maxHint(n);
  // reset the max of this progress bar as n. This may be useful when the program
  // gets new information about the current progress.
  // Can set n to be less than zero: this means that this progress bar would become
  // indefinite: the max would be unknown.
  ...
  pb.setExtraMessage("Reading..."); // Set extra message to display at the end of the bar
}
pb.stop() // stops the progress bar

Answer 6

Here is a modified version of the above:

private static boolean loading = true;
private static synchronized void loading(String msg) throws IOException, InterruptedException {
    System.out.println(msg);
    Thread th = new Thread() {
        @Override
        public void run() {
            try {
                System.out.write("\r|".getBytes());
                while(loading) {
                    System.out.write("-".getBytes());
                    Thread.sleep(500);
                }
                System.out.write("| Done \r\n".getBytes());
            } catch (IOException e) {
                e.printStackTrace();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    };
    th.start();
}

... and in main:

loading("Calculating ...");