Scanner

        Scanner scan = new Scanner(System.in);
        // 判断是否还有下一个输入
        if (scan.hasNext()) {
            String str = scan.next();
        }
        // 判断是否还有下一行输入
        if (scan.hasNextLine()) {
            String str = scan.nextLine();
        }
        //获得不同类型数据
        double a = scan.nextDouble();
        float b = scan.nextFloat();
        int c = scan.nextInt();