Java中字符串与日期转换

1.Date转String

1.1Date->String

    //date->String
    Date date = new Date();
    String format = dateFormat.format(date);
    System.out.println("format = " + format);

1.2String->Date

    //yyyy-MM-dd HH:mm:ss
    //SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    String time = "2023-04-03";
    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
    //1.string->date
    Date parse = dateFormat.parse(time);
    System.out.println("parse = " + parse);

2.Date转TimeStamp

2.1Date->TimeStamp

    //Date->TimeStamp
    Date date = new Date();
    long time = date.getTime();
    Timestamp createTime = new Timestamp(time);
    System.out.println("createTime = " + createTime);

2.2TimeStamp->Date

    //TimeStamp->Date
    Timestamp timestamp = new Timestamp(System.currentTimeMillis());
    Date timestampToDate = new Date(timestamp.getTime());
    System.out.println("timestampToDate = " + timestampToDate);

3.Date转DateTime

DateTime使用依赖

    <dependency>
        <groupId>joda-time</groupId>
        <artifactId>joda-time</artifactId>
        <version>2.9.1</version>
    </dependency>

3.1Date->DateTime

方法1：

    //method1
    Date date = new Date();
    DateTime dateTime1 = new DateTime(date);

方法2：

     //method2
    Date date = new Date();
    String dateTimeString = new DateTime(date).toString("yyyy-MM-dd");
    DateTimeFormatter dateTimeFormatter = DateTimeFormat.forPattern("yyyy-MM-dd");
    DateTime time = dateTimeFormatter.parseDateTime(dateTimeString);
    System.out.println("Date->DateTime: " + time);

3.2DateTime->Date

    //DateTime->Date
    DateTime dateTime = new DateTime();
    Date dateToDateTime = dateTime.toDate();
    System.out.println("DateTime->Date" + dateToDateTime);

4.String转DateTime

    //String->DateTime
    String dateTimeString = "2023-04-08";
    DateTimeFormatter dateTimeFormatter = DateTimeFormat.forPattern("yyyy-MM-dd");
    DateTime time = dateTimeFormatter.parseDateTime(dateTimeString);
    System.out.println("String->DateTime: " + time);
    //DateTime->String
    DateTime dt=new DateTime();
    String format="YYYY-MM-dd HH-mm-ss";
    String str= dt.toString(format);
    System.out.println("DateTime->String = " + str);

5.String与TimeStamp互转

     String timeStr = "2023-04-06 10:30:40";
    //String -> Timestamp
    Timestamp time = Timestamp.valueOf(timeStr);
    //Timestamp -> String
    String strn = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(time);
    System.out.println("Timestamp time = " + time);
    System.out.println("strn = " + strn);