简单控制台测试应用程序中的NullPointerException

这个问题已经在这里有了答案：            >            Trying to read from the console in Java                                    4个
>            What is a NullPointerException, and how do I fix it?                                    12个
我刚开始学习一些Java,并编写了这个简单的程序,但是我不知道我的代码有什么问题.

这是我在运行时看到的错误：

Exception in thread “main” java.lang.NullPointerException
at treehousejava.Main.main(Main.java:9)

这是我的代码：

package treehousejava;

import java.io.Console;

public class Main {
@SuppressWarnings("unused")
    public static void main (String[] args){
        Console console = System.console();
        String q = console.readLine("Hi there! what's your name? ");
        console.printf("hi there %s ! my name is console! ");
    }
}

解决方法:

我怀疑您想将system.in和System.out用于此类学习程序. System.console()可能在您的平台上不可用,并且该调用将返回null,因此返回NullPointException.标准输入和输出将始终可用.

Scanner scanner = new Scanner(system.in);
System.out.println("Hi there! what's your name? ");
String q = scanner.nextLine();
System.out.printf("hi there %s ! my name is console! ", q);