Java数据格式转换错误

Question

我需要一个 Java 程序从当前年份减去 5 年。一切正常，但在我运行程序之后：

DateFormat dateFormat = new SimpleDateFormat("yyyy");
Calendar cal = Calendar.getInstance();
cal.add(Calendar.YEAR,-5);
Date today = new Date();
String start = dateFormat.format(cal.getTime()).toString();
String end = dateFormat.format(today).toString();
double start_doub = Double.parseDouble(start);
double end_doub = Double.parseDouble(end);
System.out.println(start_doub);
System.out.println(end_doub);

结果是：

2012.0
2017.0

不知道程序为什么要在年份后面加.0？如何删除最后一部分？

Answer 1

您的代码如下所示

        DateFormat dateFormat = new SimpleDateFormat("yyyy");
        Calendar cal = Calendar.getInstance();
        cal.add(Calendar.YEAR,-5);
        Date today = new Date();
        String start = dateFormat.format(cal.getTime()).toString();
        String end = dateFormat.format(today).toString();
        int start_doub = Integer.parseInt(start);
        int end_doub = Integer.parseInt(end);
        System.out.println(start_doub);
        System.out.println(end_doub);

Java数据格式转换错误

Java wrong data format transformation

java

date

simpledateformat

date-formatting