Java application that prints its own source code

Question

I have a little quiz that I cannot solve by myself. I want to build a program that will print its own source code with java. Anyone knows how to do this? Like this example:

public class SourcePrint {

    private static final long serialVersionUID = 1L;

    public void test(){
        System.out.println("Hi I'm test");

    }
    public static void main(String[] args) {
        new SourcePrint().test();
    }

}

when we run this, the output would be same like this:

public class SourcePrint {

    private static final long serialVersionUID = 1L;

    public void test(){
        System.out.println("Hi I'm test");

    }
    public static void main(String[] args) {
        new SourcePrint().test();
    }

}

I don't know how to do this. Anybody know the solution or at least the hint? This is not the decompiler, the quiz maker told me the hint is "STATIC".

Quines generally involve printing the source without reading it in from its own source file, which is regarded as cheating [in regards to this kind of problem]. Does your solution requirement specify whether you allowed to do this? — yoonsi, Jun 26 '12 at 04:15

score 6 · Answer 1 · edited Jun 26 '12 at 04:41

6

http://en.wikipedia.org/wiki/Quine_%28computing%29

edited Jun 26 '12 at 04:41

gobernador

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answered Jun 26 '12 at 04:09

Rick Mangi

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A link is not an answer. – dan1st Dec 29 '19 at 19:55

score 3 · Answer 2 · edited Nov 09 '17 at 11:55

3

Here is an example that may be of use for Quine in java:

public class Quine {

    static String s = "public class Quine { public static void main(String[] args) { char c=34; System.out.println(s+c+s+c+';'+'}'); } static String s=";

    public static void main(String[] args) {
        char c = 34;
        System.out.println(s + c + s + c + ';' + '}');
    }
}

and of course the seemingly mandatory link to Wikipedia: Wikipedia: Quine. depending on how large the program is this link here may also have some good examples: Java Quine

edited Nov 09 '17 at 11:55

jazzpi

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answered Jun 26 '12 at 04:17

David Kroukamp

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Last link is broken, please fix. – Georgian Nov 20 '13 at 08:06

score 3 · Answer 3 · edited Dec 17 '13 at 10:05

import java.io.*;  
class Source  
{  
    public static void main(String args[])  
    {  
        try{  

            //open the file  
        FileInputStream fstream=new FileInputStream("D://Springs WorkSpace/Testing/src/Source.java");//here pass the own java file name with full path 

            // use DataInputStream to read binary NOT text  
        // DataInputStream in=new DataInputStream(fstream);  

            //  
        BufferedReader br=new BufferedReader(new InputStreamReader(fstream));  
            //read data line by line from the file  
            String s;  
            while((s = br.readLine() ) != null)  
            {  
                System.out.println(s);  
            }  
            in.close();  
        }  
        catch(Exception e){  
            e.printStackTrace();  
        }  
    }  
}

score 2 · Answer 4 · edited Jun 26 '12 at 04:16

2

a quick google search turned up the following link:

http://en.wikipedia.org/wiki/Quine_%28computing%29

the type of program you are looking for is generally referred to as a quine.

edited Jun 26 '12 at 04:16

gobernador

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answered Jun 26 '12 at 04:07

schadr

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Java application that prints its own source code

4 Answers4