How to Delete Stuff Printed to Console by System.Out.Println()

How to delete previous character printed to console/terminal?

You might want to take a look at

System.out.printf

Look at the example shown here: http://masterex.github.com/archive/2011/10/23/java-cli-progress-bar.html

edit:

printf displays formatted strings, which means you can adapt that format and change it for your needs.

for example you could do something like:

String[] planets = {"Mars", "Earth", "Jupiter"};        
String format = "\r%s says Hello";

for(String planet : planets) {
    System.out.printf(format, planet);
try { 
        Thread.sleep(1000); 
    }catch(Exception e) { 
        //... oh dear
    }
}

Using the formatted string syntax found here: http://docs.oracle.com/javase/6/docs/api/java/util/Formatter.html#syntax

As the comment says this solution is only limited to a singular line however dependent on your needs this might be enough.

If you require a solution for the whole screen then a possible solution would be (although quite dirty) would be to hook the operating system using JNA and get a handle on the console window, find its height and then loop println() to "clear" the window then redraw your output.

If you would like to read more then I can answer more questions or here is a link: https://github.com/twall/jna

How I can delete the System.out.print and to have a unique return

You can achieve your goal by carrying out the following steps:

1. Create an empty StringBuilder object at the beginning of the cipher method (this object will hold the sequence of characters that forms the final String to be returned by that method).

2. Replace each code line of the form (where x represents an int variable)

System.out.print(Character.toString((char) x));

with the following (where (a) s represents the StringBuilder object mentioned in part 1 above, and (b) this resulting line appends the char representation of x to s):

s.append((char) x);

3. Once your StringBuilder sequence is complete, obtain the String representation of that sequence with the following method (where s is the StringBuilder object in question):

s.toString();

Here's a modified version of the cipher method which utilizes the above approach:

public static String cipher(String input2, Integer number) {
        StringBuilder builder = new StringBuilder(input2.length());
        int k = number;
        int lowerBoundlc = 97;
        int upperBoundlc = 122;
        int lowerBounduc = 65;
        int upperBounduc = 90;
        for (int i = 0; i < input2.length(); i++) {
            char c = input2.charAt(i);
            int j = (int) c;
            if ((lowerBoundlc <= j && j <= upperBoundlc) || (j == 45)) {
                if (j == 45) {
                    builder.append((char) j);
                } else {
                    int addk = j + k;
                    if (addk > upperBoundlc) {
                        int lowercase = addk % upperBoundlc;
                        int resultlc = lowerBoundlc + lowercase -1;
                        builder.append((char) resultlc);
                    } else {
                        builder.append((char) addk);
                    }
                }

            } else {
                if ((lowerBounduc <= j && j <= upperBounduc) || (j == 45)) {
                    int addnewk = j + k;
                    if (addnewk > upperBounduc) {
                        int uppercase = addnewk % upperBounduc;
                        int resultuc = lowerBounduc + uppercase -1;
                        builder.append((char) resultuc);
                    } else {
                        builder.append((char) addnewk);
                    }
                }
            }
        }
        return builder.toString();    
    }

Clear the console in Java

You can try something around these lines with System OS dependency :

final String operatingSystem = System.getProperty("os.name");

if (operatingSystem .contains("Windows")) {
    Runtime.getRuntime().exec("cls");
}
else {
    Runtime.getRuntime().exec("clear");
}

Or other way would actually be a bad way but actually to send backspaces to console till it clears out. Something like :

for(int clear = 0; clear < 1000; clear++) {
    System.out.println("\b") ;
}

Adding and removing text from the console in Java

You can delete text by using the backspace character \b. For example:

System.out.print("\b");

An example:

public class Test {

    public static final String[] frames = {"|", "/", "-", "\\"};

    public static void main(String[] args) throws Exception {
        System.out.println();

        for (int ctr = 0; ctr < 50; ctr++) {
            System.out.print(frames[ctr % frames.length]);
            Thread.sleep(250);
            System.out.print("\b");
        }
    }
}

Note, however, that this may not work in the Eclipse console, but will work outside of Eclipse.

What is a regex to replace all System.out.println() with empty space?

you can use following regex and simply do find and replace. There is a option for regex find and replace in Eclipse.

System.out.println\(([^;].*\)*);

I tested for following

 System.out.println("  ");
 System.out.println("  fdfdf");
 System.out.println(")  fdfdf");
 System.out.println(";");
 System.out.println();

This may help you to find regex find and replace in Eclipse

Here is regex online test. I put some data there. any one can test with any thing.

How can I replace text that's been printed out on screen already in Java?

That has nothing to do with java actually. Rather you want the console you are displaying in to overwrite the text.

This can be done (in any language) by sending a carriage return (\r in Java) instead of a linefeed (\n in Java). So you never use println(), only print() if you want to do that. If you add a print("\r") before the very first print it should do what you want.

BTW it would be far more elegant and simple if you built the entire time in a string and then output it all at once :)

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