Java中实现时间类型转换的代码详解

package com.lyp;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;
public class dateFormat {
    public static void main(String[] args) throws ParseException {
        //时间格式转换
        dateToString();         //时间类型转换字符串
        stringToDate();         //字符串转换时间类型
        cstToDate();            //CST格式字符串转换时间类型
        cstToGmt();             //CST时间类型转换GMT格式字符串
        gmtToString();          //GMT格式字符串转换常规字符串
        timeMillisToString();   //时间戳转换字符串
        stringToTimeMillis();   //字符串转换时间戳
        timeMillisToDate();     //时间戳转化时间格式
        dateToTimeMillis();     //时间格式转化时间戳
    }
    public static void dateToString() {
        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Date date = new Date();
        String dateStr = dateFormat.format(date);
        System.out.println("时间类型转换字符串："+date+" --> "+dateStr);
    }
    public static void stringToDate() throws ParseException {
        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String dateStr = "2022-10-14 15:08:33";
        Date date = dateFormat.parse(dateStr);
        System.out.println("字符串转换时间类型："+dateStr+" --> "+date);
    }
    public static void cstToDate() throws ParseException {
        SimpleDateFormat dateFormat = new SimpleDateFormat("EEE MMM dd HH:mm:ss zzz yyyy", Locale.US);//注意使用Locale.US参数
        String cstStr = "Tue May 16 19:30:20 CST 2022";
        Date date = dateFormat.parse(cstStr);
        System.out.println("CST格式字符串转换时间类型："+cstStr+" --> "+date);
    }
    public static void cstToGmt() {
        Date date = new Date();//默认为CST格式时间
        SimpleDateFormat dateFormat = new SimpleDateFormat("EEE MMM dd HH:mm:ss 'GMT+0800' yyyy", Locale.ENGLISH);
        String gmtStr = dateFormat.format(date);
        System.out.println("CST时间类型转换GMT格式字符串: "+date+" --> "+gmtStr);
    }
    public static void gmtToString() throws ParseException {
        String gmtStr = "Sun Oct 2 00:00:00 GMT+0800 2022";
        SimpleDateFormat dateFormat = new SimpleDateFormat("EEE MMM dd HH:mm:ss 'GMT+0800' yyyy", Locale.ENGLISH);
        SimpleDateFormat dateFormat2 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        dateFormat.setTimeZone(TimeZone.getTimeZone("GMT"));
        Date date = dateFormat.parse(gmtStr);
        String dateStr = dateFormat2.format(date);
        System.out.println("GMT格式字符串转换常规字符串："+gmtStr+" --> "+date+" --> "+dateStr);
    }
    public static void timeMillisToString() {
        Long time = System.currentTimeMillis();
        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String dateStr = dateFormat.format(new Date(time));
        System.out.println("时间戳转换字符串: "+time+" --> "+dateStr);
    }
    public static void stringToTimeMillis() throws ParseException {
        String dateStr = "2022-10-19 14:48:13";
        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Long time = dateFormat.parse(dateStr).getTime();
        System.out.println("字符串转换时间戳: "+dateStr+" --> "+time);
    }
    public static void timeMillisToDate() {
        Long time = System.currentTimeMillis();
        Date date = new Date(time);
        System.out.println("时间戳转换时间类型: "+time+" --> "+date);
    }
    public static void dateToTimeMillis() {
        Date date = new Date();
        Long time = date.getTime();
        System.out.println("时间格式转化时间戳: "+date+" --> "+time);
    }
}