Java 时间戳与格式化字符串互转

直接看代码：

import java.text.SimpleDateFormat;
import java.util.Date;
 
public class Timestamp2DateFormatUsage {
    public static void main(String[] args) {
        System.out.println("当前时间: " + timestampToFormatDatetime());
        System.out.println("当前时间戳(ms): " + formatDatetimeToTimestamp());
    }
 
    public static Long formatDatetimeToTimestamp() {
        Date date = new Date();
        long dateTimestamp = date.getTime();
 
        return dateTimestamp;
    }
 
    public static String timestampToFormatDatetime() {
        long ts = System.currentTimeMillis();
        Date date = new Date(ts);
        String formatTime = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS").format(date);
        return formatTime;
    }
}

测试结果：

当前时间: 2023-12-05 16:33:08.070
当前时间戳(ms): 1701765188100