java - 线程 "main"java.util.InputMismatchException nextDouble() 错误中出现异常？

Question

这个问题已经有答案了:

Scanner is skipping nextLine() after using next() or nextFoo()? (25 个回答)

已关闭 7 年前。

CitireFisier.java

public class CitireFisier  {
    public static void main(String[] args) {
        File f = new File("fisier.txt");

        Scanner scn = null;
        try {
            scn = new Scanner(f);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }

        int size = scn.nextInt();  
        System.out.println("val  is " + size);

        double var  = scn.nextDouble();
        System.out.println("val  is " + var);
    }
}

输出

val is 3
Exception in thread "main" java.util.InputMismatchException
    at java.util.Scanner.throwFor(Unknown Source)
    at java.util.Scanner.next(Unknown Source)

fisier.txt

3
0.1 0.7 0.2 init g
0.0 0.0 1.0 g y
0.0 0.0 1.0 g y

nextDouble()收到错误，但 0.1 是 double !

Answer 1

如果您的语言环境使用逗号作为小数点分隔符，则 0.1 不是 double 。

要解决此问题，请像这样实例化您的扫描仪:

 scn = new Scanner(f).useLocale(Locale.US);