system.console.readline() throws null pointer exception

Question

i am using the following simple code to read a line of string from console but get nullpointerexception, can you folks help:

import java.io.Console;

public class readline_String {

    public static void main(String[] args)
    {
        // TODO Auto-generated method stub

        //String str=System.console().readLine();
        System.out.println("Enter an input string:");
        Console c=System.console();
        String str=c.readLine();
        System.out.println("The input string is:");
        System.out.println(str);

    }

}

From the doc of `System.console()` : "Returns : The system console, if any, otherwise _null_." — Arnaud, Mar 06 '18 at 10:40
read this https://stackoverflow.com/questions/4644415/java-how-to-get-input-from-system-console — Youcef LAIDANI, Mar 06 '18 at 10:41
Follow Java Naming Conventions: class names should start with uppercase. And don't use underscores, except for constants. — MC Emperor, Mar 06 '18 at 10:45

score 2 · Answer 1 · answered Mar 06 '18 at 10:43

2

Replace your code with:

    System.out.println("Enter an input string:");
    Scanner sc = new Scanner(System.in);
    String str = sc.nextLine();
    System.out.println("The input string is:");
    System.out.println(str);

answered Mar 06 '18 at 10:43

Maciej

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14

Hi Maciej, thanks so much this works. Not sure why it doesn't work with system.console.readline() – Dilip Jena Mar 06 '18 at 10:52

score 2 · Answer 2 · answered Mar 06 '18 at 11:50

If you are trying in a IDE(ex: NetBeans) it might show NullPointerException

It shows proper output in a cmd: code:

public class InputConsole {
    public static void main(String[] args) {
        System.out.print("Enter something:");
String input = System.console().readLine();
        System.out.println("input: "+input);
    }
}

Output:

Alternatively you can use Scanner or BufferedReader

system.console.readline() throws null pointer exception

2 Answers2